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The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, January 29, 2003 — 9:15 a.m. to 12:15 p.m., only You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. Your answer booklet for Part B–2 and Part C is stapled in the center of this examination booklet. Open the examination booklet, carefully remove your answer booklet, and close the examination booklet. Then fill in the heading of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for your use while taking this examination. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 1 Which statement best describes electrons? (1) They are positive subatomic particles are found in the nucleus. (2) They are positive subatomic particles are found surrounding the nucleus. (3) They are negative subatomic particles are found in the nucleus. (4) They are negative subatomic particles are found surrounding the nucleus. 6 Which Group of the Periodic Table contains atoms with a stable outer electron configuration? (1) 1 (3) 16 (2) 8 (4) 18 and and and 7 From which of these atoms in the ground state can a valence electron be removed using the least amount of energy? (1) nitrogen (3) oxygen (2) carbon (4) chlorine and 2 During a flame test, ions of a specific metal are heated in the flame of a gas burner. A characteristic color of light is emitted by these ions in the flame when the electrons (1) gain energy as they return to lower energy levels (2) gain energy as they move to higher energy levels (3) emit energy as they return to lower energy levels (4) emit energy as they move to higher energy levels 8 What is the percent by mass of oxygen in H2SO4? [formula mass = 98] (1) 16% (3) 65% (2) 33% (4) 98% 9 An atom of carbon-12 and an atom of carbon-14 differ in (1) atomic number (2) mass number (3) nuclear charge (4) number of electrons 3 In which list are the elements arranged in order of increasing atomic mass? (1) Cl, K, Ar (3) Te, I, Xe (2) Fe, Co, Ni (4) Ne, F, Na 10 The strength of an atom’s attraction for the electrons in a chemical bond is the atom’s (1) electronegativity (3) heat of reaction (2) ionization energy (4) heat of formation 4 In which compound does chlorine have the highest oxidation number? (1) NaClO (3) NaClO3 (2) NaClO2 (4) NaClO4 11 Which type or types of change, if any, can reach equilibrium? (1) a chemical change, only (2) a physical change, only (3) both a chemical and a physical change (4) neither a chemical nor a physical change 5 Which event must always occur for a chemical reaction to take place? (1) formation of a precipitate (2) formation of a gas (3) effective collisions between reacting particles (4) addition of a catalyst to the reaction system P.S./Chem.–Jan. ’03 12 An increase in the average kinetic energy of a sample of copper atoms occurs with an increase in (1) concentration (3) pressure (2) temperature (4) volume [2] 16 One similarity between all mixtures and compounds is that both (1) are heterogeneous (2) are homogeneous (3) combine in a definite ratio (4) consist of two or more substances 13 The empirical formula of a compound is CH2. Which molecular formula is correctly paired with a structural formula for this compound? (1) (2) (3) C2H4 C2H4 C3H8 H H H C C H H H C C H H H H H C C C H H H 17 Which phase change results in the release of energy? (1) H2O(s) → H2O() (2) H2O(s) → H2O(g) (3) H2O() → H2O(g) (4) H2O(g) → H2O() H H 18 Which compound has an isomer? H H (1) H C H (4) C3H8 H H H H C C C H H H H H H H (2) H C C H H H H H (3) H C C C H H H H H H H H (4) H C C C C H H H H H 14 Given the equation: F + 1e – – 19 What occurs when NaCl(s) is added to water? (1) The boiling point of the solution increases, and the freezing point of the solution decreases. (2) The boiling point of the solution increases, and the freezing point of the solution increases. (3) The boiling point of the solution decreases, and the freezing point of the solution decreases. (4) The boiling point of the solution decreases, and the freezing point of the solution increases. F This equation represents the formation of a (1) fluoride ion, which is smaller in radius than a fluorine atom (2) fluoride ion, which is larger in radius than a fluorine atom (3) fluorine atom, which is smaller in radius than a fluoride ion (4) fluorine atom, which is larger is radius than a fluoride ion 20 Which radioisotope is a beta emitter? (1) 90Sr (3) 37K (2) 220Fr (4) 238U 15 The high electrical conductivity of metals is primarily due to (1) high ionization energies (2) filled energy levels (3) mobile electrons (4) high electronegativities P.S./Chem.–Jan. ’03 21 When a mixture of water, sand, and salt is filtered, what passes through the filter paper? (1) water, only (2) water and sand, only (3) water and salt, only (4) water, sand, and salt [3] [OVER] 27 When a neutral atom undergoes oxidation, the atom’s oxidation state (1) decreases as it gains electrons (2) decreases as it loses electrons (3) increases as it gains electrons (4) increases as it loses electrons 22 A hydrate is a compound that includes water molecules within its crystal structure. During an experiment to determine the percent by mass of water in a hydrated crystal, a student found the mass of the hydrated crystal to be 4.10 grams. After heating to constant mass, the mass was 3.70 grams. What is the percent by mass of water in this crystal? (1) 90.% (3) 9.8% (2) 11% (4) 0.40% 28 Given the equation: C(s) + H2O(g) → CO(g) + H2(g) Which species undergoes reduction? 23 Which of these 1 M solutions will have the highest pH? (1) NaOH (3) HCl (2) CH3OH (4) NaCl (1) C(s) (2) H+ 29 Which equation is an example of artificial transmutation? (1) 94Be + 42He → 126C + 10n (2) U + 3 F2 → UF6 (3) Mg(OH)2 + 2 HCl → 2 H2O + MgCl2 (4) Ca + 2 H2O → Ca(OH)2 + H2 24 Which physical property makes it possible to separate the components of crude oil by means of distillation? (1) melting point (3) solubility (2) conductivity (4) boiling point 30 Which species can conduct an electric current? (1) NaOH(s) (3) H2O(s) (2) CH3OH(aq) (4) HCl(aq) 25 In saturated hydrocarbons, carbon atoms are bonded to each other by (1) single covalent bonds, only (2) double covalent bonds, only (3) alternating single and double covalent bonds (4) alternating double and triple covalent bonds 26 Which formula correctly represents the product of an addition reaction between ethene and chlorine? (1) CH2Cl2 (3) C2H4Cl2 (2) CH3Cl (4) C2H3Cl P.S./Chem.–Jan. ’03 (3) C2+ (4) H2(g) [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 According to Table N, which radioactive isotope is best for determining the actual age of Earth? (3) 60Co (1) 238U 90 (2) Sr (4) 14C 36 Hydrogen has three isotopes with mass numbers of 1, 2, and 3 and has an average atomic mass of 1.00794 amu. This information indicates that (1) equal numbers of each isotope are present (2) more isotopes have an atomic mass of 2 or 3 than of 1 (3) more isotopes have an atomic mass of 1 than of 2 or 3 (4) isotopes have only an atomic mass of 1 32 Given the following solutions: Solution A: pH of 10 Solution B: pH of 7 Solution C: pH of 5 Which list has the solutions placed in order of increasing H+ concentration? (3) C, A, B (4) C, B, A 33 Which statement explains why nuclear waste materials may pose a problem? (1) They frequently have short half-lives and remain radioactive for brief periods of time. (2) They frequently have short half-lives and remain radioactive for extended periods of time. (3) They frequently have long half-lives and remain radioactive for brief periods of time. (4) They frequently have long half-lives and remain radioactive for extended periods of time. 38 Given the reaction: S(s) + O2(g) → SO2(g) + energy 35 Which of the following solids has the highest melting point? (3) SO2(s) (1) H2O(s) (2) Na2O(s) (4) CO2(s) P.S./Chem.–Jan. ’03 Reaction Coordinate Reaction Coordinate (1) (3) Potential Energy 34 A compound whose water solution conducts electricity and turns phenolphthalein pink is (1) HCl (3) NaOH (2) HC2H3O2 (4) CH3OH Potential Energy Potential Energy Which diagram best represents the potential energy changes for this reaction? [5] Potential Energy (1) A, B, C (2) B, A, C 37 Which list of elements contains two metalloids? (1) Si, Ge, Po, Pb (3) Si, P, S, Cl (2) As, Bi, Br, Kr (4) Po, Sb, I, Xe Reaction Coordinate Reaction Coordinate (2) (4) [OVER] 39 A chemist performs the same tests on two homogeneous white crystalline solids, A and B. The results are shown in the table below. Solid A Solid B Melting Point High, 801°C Low, decomposes at 186°C Solubility in H2O (grams per 100.0 g H2O at 0°C) 35.7 3.2 Electrical Conductivity (in aqueous solution) Good conductor Nonconductor The results of these tests suggest that (1) both solids contain only ionic bonds (2) both solids contain only covalent bonds (3) solid A contains only covalent bonds and solid B contains only ionic bonds (4) solid A contains only ionic bonds and solid B contains only covalent bonds 43 A student intended to make a salt solution with a concentration of 10.0 grams of solute per liter of solution. When the student’s solution was analyzed, it was found to contain 8.90 grams of solute per liter of solution. What was the percent error in the concentration of the solution? (1) 1.10% (3) 11.0% (2) 8.90% (4) 18.9% 40 Solubility data for four different salts in water at 60°C are shown in the table below. Salt Solubility in Water at 60°C A 10 grams / 50 grams H2O B 20 grams / 60 grams H2O C 30 grams / 120 grams H2O D 40 grams/ 80 grams H2O 44 What is the molarity of a solution of NaOH if 2 liters of the solution contains 4 moles of NaOH? (1) 0.5 M (3) 8 M (2) 2 M (4) 80 M Which salt is most soluble at 60°C? (1) A (2) B (3) C (4) D 45 A gas occupies a volume of 40.0 milliliters at 20°C. If the volume is increased to 80.0 milliliters at constant pressure, the resulting temperature will be equal to 41 Which phase change represents a decrease in entropy? (1) solid to liquid (3) liquid to gas (2) gas to liquid (4) solid to gas 42 Given the equation: 2 C2H2(g) + 5 O2(g) → 4 CO2(g) + 2 H2O(g) P.S./Chem.–Jan. ’03 80.0 mL 40.0 mL (3) 293 K × 80.0 mL 40.0 mL (2) 20°C × 40.0 mL 80.0 mL (4) 293 K × 40.0 mL 80.0 mL 46 According to Reference Table J, which of these metals will react most readily with 1.0 M HCl to produce H2(g)? (1) Ca (3) Mg (2) K (4) Zn How many moles of oxygen are required to react completely with 1.0 mole of C2H2? (1) 2.5 (2) 2.0 (1) 20°C × (3) 5.0 (4) 10 [6] 47 The graph below represents the heating curve of a substance that starts as a solid below its freezing point. • Temperature (°C) 120 90 • 60 • • • 30 • Time (minutes) What is the melting point of this substance? (1) 30°C (2) 55°C 50 Given the system at equilibrium: N2O4(g) + 58.1 kJ 2 NO2(g) 48 Given the unbalanced equation: __Fe2O3 + __CO → __Fe + __CO2 When the equation is correctly balanced using the smallest whole-number coefficients, what is the coefficient of CO? (1) 1 (2) 2 What will be the result of an increase in temperature at constant pressure? (1) The equilibrium will shift to the left, and the concentration of NO2(g) will decrease. (2) The equilibrium will shift to the left, and the concentration of NO2(g) will increase. (3) The equilibrium will shift to the right, and the concentration of NO2(g) will decrease. (4) The equilibrium will shift to the right, and the concentration of NO2(g) will increase. (3) 3 (4) 4 49 Which type of organic compound is represented by the structural formula shown below? H (1) aldehyde (2) alcohol P.S./Chem.–Jan. ’03 H H H C C C H OH H (3) 90°C (4) 120°C H (3) ether (4) ester [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–61): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 In the boxes provided in your answer booklet: a Draw two different compounds, one in each box, using the representations for atoms of element X and element Z given below. [1] Atom of element X = Atom of element Z = b Draw a mixture of these two compounds. [1] •° 52 At equilibrium, nitrogen, hydrogen, and ammonia gases form a mixture in a sealed container. The data table below gives some characteristics of these substances. Data Table Gas Boiling Point Melting Point Solubility in Water Nitrogen –196°C –210°C insoluble Hydrogen –252°C –259°C insoluble Ammonia –33°C –78°C soluble Describe how to separate ammonia from hydrogen and nitrogen. [1] Base your answers to questions 53 through 55 on the diagram of a voltaic cell provided in your answer booklet and on your knowledge of chemistry. 53 On the diagram provided in your answer booklet, indicate with one or more arrows the direction of electron flow through the wire. [1] 54 Write an equation for the half-reaction that occurs at the zinc electrode. 55 Explain the function of the salt bridge. [1] [1] 56 Given the nuclear equation: 235U 92 91 1 + 10n → 142 56Ba + 36Kr + 3 0n + energy a State the type of nuclear reaction represented by the equation. [1] b The sum of the masses of the products is slightly less than the sum of the masses of the reactants. Explain this loss of mass. [1] c This process releases greater energy than an ordinary chemical reaction does. Name another type of nuclear reaction that releases greater energy than an ordinary chemical reaction. [1] P.S./Chem.–Jan. ’03 [8] Base your answers to questions 57 through 60 on the information below. Each molecule listed below is formed by sharing electrons between atoms when the atoms within the molecule are bonded together. Molecule A: Cl2 Molecule B: CCl4 Molecule C: NH3 57 In the box provided in your answer booklet, draw the electron-dot (Lewis) structure for the NH3 molecule. [1] 58 Explain why CCl4 is classified as a nonpolar molecule. [1] 59 Explain why NH3 has stronger intermolecular forces of attraction than Cl2. [1] 60 Explain how the bonding in KCl is different from the bonding in molecules A, B, and C. [1] 61 How is the bonding between carbon atoms different in unsaturated hydrocarbons and saturated hydrocarbons? [1] P.S./Chem.–Jan. ’03 [9] [OVER] Part C Answer all questions in this part. Directions (62–74): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 62 through 64 on the information and diagram below. One model of the atom states that atoms are tiny particles composed of a uniform mixture of positive and negative charges. Scientists conducted an experiment where alpha particles were aimed at a thin layer of gold atoms. Most of the alpha particles passed directly through the gold atoms. A few alpha particles were deflected from their straight-line paths. An illustration of the experiment is shown below. Alpha particles Deflected alpha particle Gold atoms 62 Most of the alpha particles passed directly through the gold atoms undisturbed. What does this evidence suggest about the structure of the gold atoms? [1] 63 A few of the alpha particles were deflected. What does this evidence suggest about the structure of the gold atoms? [1] 64 How should the original model be revised based on the results of this experiment? P.S./Chem.–Jan. ’03 [10] [1] Base your answers to questions 65 through 67 on the information below. When cola, a type of soda pop, is manufactured, CO2(g) is dissolved in it. 65 A capped bottle of cola contains CO2(g) under high pressure. When the cap is removed, how does pressure affect the solubility of the dissolved CO2(g)? [1] 66 A glass of cold cola is left to stand 5 minutes at room temperature. How does temperature affect the solubility of the CO2(g)? [1] 67 a In the space provided in your answer booklet, draw a set of axes and label one of them “Solubility” and the other “Temperature.” [1] b Draw a line to indicate the solubility of CO2(g) versus temperature on the axes drawn in part a. [1] Base your answers to questions 68 through 70 on the graph below, which shows the vapor pressure curves for liquids A and B. 800 700 Pressure (mm Hg) 600 500 400 A 300 B 200 100 0 0 10 20 30 40 50 60 70 80 90 100 110 120 Temperature (°C) 68 What is the vapor pressure of liquid A at 70°C? Your answer must include correct units. [2] 69 At what temperature does liquid B have the same vapor pressure as liquid A at 70°C? Your answer must include correct units. [2] 70 Which liquid will evaporate more rapidly? Explain your answer in terms of intermolecular forces. [2] P.S./Chem.–Jan. ’03 [11] [OVER] Base your answers to question 71 through 74 on the information and data table below. A titration setup was used to determine the unknown molar concentration of a solution of NaOH. A 1.2 M HCl solution was used as the titration standard. The following data were collected. Trial 1 Trial 2 Trial 3 Trial 4 Amount of HCI Standard Used 10.0 mL 10.0 mL 10.0 mL 10.0 mL Initial NaOH Buret Reading 0.0 mL 12.2 mL 23.2 mL 35.2 mL Final NaOH Buret Reading 12.2 mL 23.2 mL 35.2 mL 47.7 mL 71 Calculate the volume of NaOH solution used to neutralize 10.0 mL of the standard HCl solution in trial 3. Show your work. [2] 72 According to Reference Table M, what indicator would be most appropriate in determining the end point of this titration? Give one reason for choosing this indicator. [2] 73 Calculate the average molarity of the unknown NaOH solution for all four trials. Your answer must include the correct number of significant figures and correct units. [3] 74 Explain why it is better to use the average data from multiple trials rather than the data from a single trial to calculate the results of the titration. [1] P.S./Chem.–Jan. ’03 [12] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, January 29, 2003 — 9:15 a.m. to 12:15 p.m., only Student ANSWER SHEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher .............................................. ■ Male ■ Female Grade ........... School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Wednesday, January 29, 2003 — 9:15 a.m. to 12:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A 30 B–1 20 B–2 14 C 21 Student’s Score ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION Grade . . . . . . . . . Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Raters’ Initials: Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only Part B–2 51 a 51a b b 52 52 [a] [OVER] For Raters Only Voltaic Cell 53 Wire V Voltmeter Wire Salt bridge Zinc strip Electrolyte Copper strip 53 Electrolyte 54 54 55 55 56 a 56a b b c c 57 57 58 58 [b] For Raters Only 59 59 60 60 61 61 Total Score for Part B–2 Part C 62 62 63 63 64 64 65 65 66 66 [c] [OVER] For Raters Only 67 a and b 67a b 68 68 69 69 70 Liquid: Explanation: 70 71 71 mL 72 Indicator: Reason: 72 73 73 74 74 [d] Total Score for Part C The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Tuesday, June 24, 2003 — 9:15 a.m. to 12:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for your use while taking this examination. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. Part A Answer all questions in this part. Directions (1–35): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 Alpha particles are emitted during the radioactive decay of (1) carbon-14 (3) calcium-37 (2) neon-19 (4) radon-222 1 The atomic number of an atom is always equal to the number of its (1) protons, only (2) neutrons, only (3) protons plus neutrons (4) protons plus electrons 8 Which is an empirical formula? (1) P2O5 (3) C2H4 (2) P4O6 (4) C3H6 2 Which subatomic particle has no charge? (1) alpha particle (3) neutron (2) beta particle (4) electron 9 Which substance can be decomposed by a chemical change? (1) Co (3) Cr (2) CO (4) Cu 3 When the electrons of an excited atom return to a lower energy state, the energy emitted can result in the production of (1) alpha particles (3) protons (2) isotopes (4) spectra 10 The percent by mass of calcium in the compound calcium sulfate (CaSO4) is approximately (1) 15% (3) 34% (2) 29% (4) 47% 4 The atomic mass of an element is calculated using the (1) atomic number and the ratios of its naturally occurring isotopes (2) atomic number and the half-lives of each of its isotopes (3) masses and the ratios of its naturally occurring isotopes (4) masses and the half-lives of each of its isotopes 11 What is represented by the dots in a Lewis electron-dot diagram of an atom of an element in Period 2 of the Periodic Table? (1) the number of neutrons in the atom (2) the number of protons in the atom (3) the number of valence electrons in the atom (4) the total number of electrons in the atom 5 The region that is the most probable location of an electron in an atom is (1) the nucleus (3) the excited state (2) an orbital (4) an ion 12 Which type of chemical bond is formed between two atoms of bromine? (1) metallic (3) ionic (2) hydrogen (4) covalent 6 Which is a property of most nonmetallic solids? (1) high thermal conductivity (2) high electrical conductivity (3) brittleness (4) malleability P.S./Chem.–June ’03 13 [2] Which of these formulas contains the most polar bond? (1) H–Br (3) H–F (2) H–Cl (4) H–I 14 According to Table F, which of these salts is least soluble in water? (1) LiCl (3) FeCl2 (2) RbCl (4) PbCl2 22 Which statement correctly describes an endothermic chemical reaction? (1) The products have higher potential energy than the reactants, and the ∆H is negative. (2) The products have higher potential energy than the reactants, and the ∆H is positive. (3) The products have lower potential energy than the reactants, and the ∆H is negative. (4) The products have lower potential energy than the reactants, and the ∆H is positive. 15 Which of these terms refers to matter that could be heterogeneous? (1) element (3) compound (2) mixture (4) solution 23 At standard pressure when NaCl is added to water, the solution will have a (1) higher freezing point and a lower boiling point than water (2) higher freezing point and a higher boiling point than water (3) lower freezing point and a higher boiling point than water (4) lower freezing point and a lower boiling point than water 16 In which material are the particles arranged in a regular geometric pattern? (3) H2O() (1) CO2(g) (2) NaCl(aq) (4) C12H22O11(s) 17 Which change is exothermic? (1) freezing of water (2) melting of iron (3) vaporization of ethanol (4) sublimation of iodine 24 Which element has atoms that can form single, double, and triple covalent bonds with other atoms of the same element? (1) hydrogen (3) fluorine (2) oxygen (4) carbon 18 Which type of change must occur to form a compound? (1) chemical (3) nuclear (2) physical (4) phase 25 Which compound is an isomer of pentane? (1) butane (3) methyl butane (2) propane (4) methyl propane 19 Which formula correctly represents the composition of iron (III) oxide? (3) Fe3O (1) FeO3 (2) Fe2O3 (4) Fe3O2 26 In which substance does chlorine have an oxidation number of +1? (1) Cl2 (3) HClO (2) HCl (4) HClO2 20 Given the reaction: PbCl2(aq) + Na2CrO4(aq) → PbCrO4(s) + 2 NaCl(aq) 27 Which statement is true for any electrochemical cell? (1) Oxidation occurs at the anode, only. (2) Reduction occurs at the anode, only. (3) Oxidation occurs at both the anode and the cathode. (4) Reduction occurs at both the anode and the cathode. What is the total number of moles of NaCl formed when 2 moles of Na2CrO4 react completely? (1) 1 mole (2) 2 moles (3) 3 moles (4) 4 moles 21 Which hydrocarbon is saturated? (1) propene (3) butene (2) ethyne (4) heptane P.S./Chem.–June ’03 [3] [OVER] 32 Which type of radioactive emission has a positive charge and weak penetrating power? (1) alpha particle (3) gamma ray (2) beta particle (4) neutron 28 Given the equation: 2 Al + 3 Cu2+ → 2 Al3+ + 3 Cu The reduction half-reaction is (1) Al → Al3+ + 3e– (2) Cu2+ + 2e– → Cu (3) Al + 3e– → Al3+ (4) Cu2+ → Cu + 2e– 33 Which substance contains metallic bonds? (1) Hg() (3) NaCl(s) (2) H2O() (4) C6H12O6(s) 29 Which 0.1 M solution contains an electrolyte? (3) CH3OH(aq) (1) C6H12O6(aq) (2) CH3COOH(aq) (4) CH3OCH3(aq) 34 What is the name of the process in which the nucleus of an atom of one element is changed into the nucleus of an atom of a different element? (1) decomposition (3) substitution (2) transmutation (4) reduction 30 Which equation represents a neutralization reaction? (1) Na2CO3 + CaCl2 → 2 NaCl + CaCO3 (2) Ni(NO3)2 + H2S → NiS + 2 HNO3 (3) NaCl + AgNO3 → AgCl + NaNO3 (4) H2SO4 + Mg(OH)2 → MgSO4 + 2 H2O Note that question 35 has only three choices. 35 A catalyst is added to a system at equilibrium. If the temperature remains constant, the activation energy of the forward reaction (1) decreases (2) increases (3) remains the same 31 An Arrhenius acid has (1) only hydroxide ions in solution (2) only hydrogen ions in solution (3) hydrogen ions as the only positive ions in solution (4) hydrogen ions as the only negative ions in solution P.S./Chem.–June ’03 [4] Part B–1 Answer all questions in this part. Directions (36–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 43 The potential energy diagram below represents a reaction. 36 The nucleus of an atom of K-42 contains (1) 19 protons and 23 neutrons (2) 19 protons and 42 neutrons (3) 20 protons and 19 neutrons (4) 23 protons and 19 neutrons Potential Energy B 37 What is the total number of electrons in a Cu+ ion? (1) 28 (3) 30 (2) 29 (4) 36 38 Which list of elements is arranged in order of increasing atomic radii? (1) Li, Be, B, C (3) Sc, Ti, V, Cr (2) Sr, Ca, Mg, Be (4) F, Cl, Br, I C A D Reaction Coordinate Which arrow represents the activation energy of the forward reaction? (1) A (2) B 39 Which isotope is most commonly used in the radioactive dating of the remains of organic materials? (3) 32P (1) 14C 16 (2) N (4) 37K (3) C (4) D 44 Given the formulas of four organic compounds: H H O (a) H C C C 40 According to Reference Table H, what is the vapor pressure of propanone at 45°C? (1) 22 kPa (3) 70. kPa (2) 33 kPa (4) 98 kPa H H H O OH H H H H H H OH H Which pair below contains an alcohol and an acid? (1) a and b (2) a and c 42 Hexane (C6H14) and water do not form a solution. Which statement explains this phenomenon? (1) Hexane is polar and water is nonpolar. (2) Hexane is ionic and water is polar. (3) Hexane is nonpolar and water is polar. (4) Hexane is nonpolar and water is ionic. [5] H (d) H C C C H H H 41 The freezing point of bromine is (1) 539°C (3) 7°C (2) –539°C (4) –7°C H (c) H C C C H H (b) H C C C P.S./Chem.–June ’03 H O (3) b and d (4) c and d [OVER] 45 Which type of reaction is represented by the equation below? Note: n and n are very large numbers equal to about 2000. H H n C C H H (1) esterification (2) fermentation V Voltmeter Salt bridge Pb(s) + Cu2 +(aq) Cu(s) 1.0 M Cu2+(aq) H H n Solution Conductivity Color with Phenolphthalein A Good Colorless B Poor Colorless C Good Pink D Poor Pink (1) A (2) B Pb2 +(aq) + Cu(s) (3) C (4) D 239 49 In the reaction 239 93Np → 94Pu + X, what does X represent? (1) a neutron (3) an alpha particle (2) a proton (4) a beta particle the Pb(s) to the Cu(s) the Cu(s) to the Pb(s) the Pb2+(aq) to the Pb(s) the Cu2+(aq) to the Cu(s) Note that question 50 has only three choices. 50 As carbon dioxide sublimes, its entropy (1) decreases (2) increases (3) remains the same 47 Which ion has the same electron configuration as an atom of He? (3) Na+ (1) H– 2– (2) O (4) Ca2+ P.S./Chem.–June ’03 C Based on the data table, which unknown solution could be 0.1 M NaOH? When the switch is closed, electrons will flow from (1) (2) (3) (4) C 48 A student was given four unknown solutions. Each solution was checked for conductivity and tested with phenolphthalein. The results are shown in the data table below. Switch 1.0 M Pb2+(aq) H (3) saponification (4) polymerization 46 A diagram of a chemical cell and an equation are shown below. Pb(s) H [6] Part B–2 Answer all questions in this part. Directions (51–63): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 and 52 on the electron configuration table shown below. Element Electron Configuration X 2–8–8–2 Y 2–8–7–3 Z 2–8–8 51 What is the total number of valence electrons in an atom of electron configuration X? [1] 52 Which electron configuration represents the excited state of a calcium atom? [1] Base your answers to questions 53 and 54 on the information below. Given: Samples of Na, Ar, As, Rb 53 Which two of the given elements have the most similar chemical properties? 54 Explain your answer in terms of the Periodic Table of the Elements. [1] [1] Base your answers to questions 55 and 56 on the information below. Diethyl ether is widely used as a solvent. 55 In the space provided in your answer booklet, draw the structural formula for diethyl ether. [1] 56 In the space provided in your answer booklet, draw the structural formula for an alcohol that is an isomer of diethyl ether. [1] P.S./Chem.–June ’03 [7] [OVER] Base your answers to questions 57 and 58 on the information below. Two chemistry students each combine a different metal with hydrochloric acid. Student A uses zinc, and hydrogen gas is readily produced. Student B uses copper, and no hydrogen gas is produced. 57 State one chemical reason for the different results of students A and B. [1] 58 Using Reference Table J, identify another metal that will react with hydrochloric acid to yield hydrogen gas. [1] 59 Given the reaction between two different elements in the gaseous state: + + Box A below represents a mixture of the two reactants before the reaction occurs. The product of this reaction is a gas. In Box B provided in your answer booklet, draw the system after the reaction has gone to completion, based on the Law of Conservation of Matter. [2] Box A System Before Reaction 60 As a neutral sulfur atom gains two electrons, what happens to the radius of the atom? [1] 61 After a neutral sulfur atom gains two electrons, what is the resulting charge of the ion? [1] 62 a In the space provided in your answer booklet, calculate the heat released when 25.0 grams of water freezes at 0°C. Show all work. [1] b Record your answer with an appropriate unit. [1] 63 State one difference between voltaic cells and electrolytic cells. Include information about both types of cells in your answer. [1] P.S./Chem.–June ’03 [8] Part C Answer all questions in this part. Directions (64–79): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 64 and 65 on the diagram below, which shows a piston confining a gas in a cylinder. 64 Using the set of axes provided in your answer booklet, sketch the general relationship between the pressure and the volume of an ideal gas at constant temperature. [1] 65 The gas volume in the cylinder is 6.2 milliliters and its pressure is 1.4 atmospheres. The piston is then pushed in until the gas volume is 3.1 milliliters while the temperature remains constant. a In the space provided in your answer booklet, calculate the pressure, in atmospheres, after the change in volume. Show all work. [1] b Record your answer. [1] 66 A student recorded the following buret readings during a titration of a base with an acid: Standard 0.100 M HCl Unknown KOH Initial reading 9.08 mL 0.55 mL Final reading 19.09 mL 5.56 mL a In the space provided in your answer booklet, calculate the molarity of the KOH. Show all work. [1] b Record your answer to the correct number of significant figures. [1] 67 John Dalton was an English scientist who proposed that atoms were hard, indivisible spheres. In the modern model, the atom has a different internal structure. a Identify one experiment that led scientists to develop the modern model of the atom. [1] b Describe this experiment. [1] c State one conclusion about the internal structure of the atom, based on this experiment. [1] P.S./Chem.–June ’03 [9] [OVER] Base your answers to questions 68 through 73 on the information below and on your knowledge of chemistry. Nuclear Waste Storage Plan for Yucca Mountain In 1978, the U.S. Department of Energy began a study of Yucca Mountain which is located 90 miles from Las Vegas, Nevada. The study was to determine if Yucca Mountain would be suitable for a long-term burial site for high-level radioactive waste. A threedimensional (3-D) computer scale model of the site was used to simulate the Yucca Mountain area. The computer model study for Yucca Mountain included such variables as: the possibility of earthquakes, predicted water flow through the mountain, increased rainfall due to climate changes, radioactive leakage from the waste containers, and increased temperatures from the buried waste within the containers. The containers that will be used to store the radioactive waste are designed to last 10,000 years. Within the 10,000-year time period, cesium and strontium, the most powerful radioactive emitters, would have decayed. Other isotopes found in the waste would decay more slowly, but are not powerful radioactive emitters. In 1998, scientists discovered that the compressed volcanic ash making up Yucca Mountain was full of cracks. Because of the arid climate, scientists assumed that rainwater would move through the cracks at a slow rate. However, when radioactive chlorine-36 was found in rock samples at levels halfway through the mountain, it was clear that rainwater had moved quickly down through Yucca Mountain. It was only 50 years earlier when this chlorine-36 isotope had contaminated rainwater during atmospheric testing of the atom bomb. Some opponents of the Yucca Mountain plan believe that the uncertainties related to the many variables of the computer model result in limited reliability of its predictions. However, advocates of the plan believe it is safer to replace the numerous existing radioactive burial sites around the United States with the one site at Yucca Mountain. Other opponents of the plan believe that transporting the radioactive waste to Yucca Mountain from the existing 131 burial sites creates too much danger to the United States. In 2002, after years of political debate, a final legislative vote approved the development of Yucca Mountain to replace the existing 131 burial sites. 68 State one uncertainty in the computer model that limits the reliability of this computer model. [1] 69 Scientists assume that a manufacturing defect would cause at least one of the waste containers stored in the Yucca Mountain repository to leak within the first 1,000 years. State one possible effect such a leak could have on the environment near Yucca Mountain. [1] 70 State one risk associated with leaving radioactive waste in the 131 sites around the country where it is presently stored. [1] 71 If a sample of cesium-137 is stored in a waste container in Yucca Mountain, how much time must elapse until only 1 32 of the original sample remains unchanged? [1] 72 The information states “Within the 10,000-year time period, cesium and strontium, the most powerful radioactive emitters, would have decayed.” Use information from Reference Table N to support this statement. [1] 73 Why is water flow a crucial factor in deciding whether Yucca Mountain is a suitable burial site? [1] P.S./Chem.–June ’03 [10] Base your answers to questions 74 through 76 on the information below. A student wishes to investigate how the reaction rate changes with a change in concentration of HCl(aq). Given the reaction: Zn(s) + HCl(aq) → H2(g) + ZnCl2(aq) 74 Identify the independent variable in this investigation. [1] 75 Identify one other variable that might affect the rate and should be held constant during this investigation. [1] 76 Describe the effect of increasing the concentration of HCl(aq) on the reaction rate and justify your response in terms of collision theory. [1] Base your answers to questions 77 through 79 on the information below. A truck carrying concentrated nitric acid overturns and spills its contents. The acid drains into a nearby pond. The pH of the pond water was 8.0 before the spill. After the spill, the pond water is 1,000 times more acidic. 77 Name an ion in the pond water that has increased in concentration due to this spill. [1] 78 What is the new pH of the pond water after the spill? 79 What color would bromthymol blue be at this new pH? P.S./Chem.–June ’03 [11] [1] [1] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Tuesday, June 24, 2003 — 9:15 a.m. to 12:15 p.m., only Student ANSWER SHEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher .............................................. ■ Male ■ Female Grade ........... School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 13 . . . . . . . . . . . . 25 . . . . . . . . . . . 36 . . . . . . . . . . . . 44 . . . . . . . . . . . . 2 ............ 14 . . . . . . . . . . . . 26 . . . . . . . . . . . 37 . . . . . . . . . . . . 45 . . . . . . . . . . . . 3 ............ 15 . . . . . . . . . . . . 27 . . . . . . . . . . . 38 . . . . . . . . . . . . 46 . . . . . . . . . . . . 4 ............ 16 . . . . . . . . . . . . 28 . . . . . . . . . . . 39 . . . . . . . . . . . . 47 . . . . . . . . . . . . 5 ............ 17 . . . . . . . . . . . . 29 . . . . . . . . . . . 40 . . . . . . . . . . . . 48 . . . . . . . . . . . . 6 ............ 18 . . . . . . . . . . . . 30 . . . . . . . . . . . 41 . . . . . . . . . . . . 49 . . . . . . . . . . . . 7 ............ 19 . . . . . . . . . . . . 31 . . . . . . . . . . . 42 . . . . . . . . . . . . 50 . . . . . . . . . . . . 8 ............ 20 . . . . . . . . . . . . 32 . . . . . . . . . . . 43 . . . . . . . . . . . . Part B–1 Score 9 ............ 21 . . . . . . . . . . . . 33 . . . . . . . . . . . 10 . . . . . . . . . . . . 22 . . . . . . . . . . . . 34 . . . . . . . . . . . 11 . . . . . . . . . . . . 23 . . . . . . . . . . . . 35 . . . . . . . . . . . 12 . . . . . . . . . . . . 24 . . . . . . . . . . . . Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Tuesday, June 24, 2003 — 9:15 a.m. to 12:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION A 35 B–1 15 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only Part B–2 51 51 52 52 53 and 53 54 54 55 55 [a] [OVER] For Raters Only 56 56 57 57 58 58 59 59 Box A System Before Reaction Box B System After Reaction Has Gone to Completion 60 60 61 61 [b] For Raters Only 62 a 62a b b 63 63 Total Score for Part B–2 Part C 64 64 65 a 65a b b atm [c] [OVER] For Raters Only 66 a 66a b M b 67 a 67a b b c c 68 68 69 69 70 70 [d] For Raters Only 71 71 72 72 73 73 74 74 75 75 76 76 77 77 78 78 79 79 Total Score for Part C [e] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, August 13, 2003 — 12:30 to 3:30 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for your use while taking this examination. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. Part A Answer all questions in this part. Directions (1–35): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 Which element is a solid at STP? (1) H2 (3) N2 (2) I2 (4) O2 1 Which electron transition represents a gain of energy? (1) from 2nd to 3rd shell (2) from 2nd to 1st shell (3) from 3rd to 2nd shell (4) from 3rd to 1st shell 8 In which compound is the percent by mass of oxygen greatest? (1) BeO (3) CaO (2) MgO (4) SrO 2 Which particles are found in the nucleus of an atom? (1) electrons, only (2) neutrons, only (3) protons and electrons (4) protons and neutrons 9 Based on Reference Table F, which of these salts is the best electrolyte? (1) sodium nitrate (2) magnesium carbonate (3) silver chloride (4) barium sulfate 3 What is the total number of valence electrons in an atom of sulfur in the ground state? (1) 6 (3) 3 (2) 8 (4) 4 10 What is conserved during a chemical reaction? (1) mass, only (2) charge, only (3) both mass and charge (4) neither mass nor charge 4 An electron has a charge of (1) –1 and the same mass as a proton (2) +1 and the same mass as a proton (3) –1 and a smaller mass than a proton (4) +1 and a smaller mass than a proton 11 Which type of bond is formed when electrons are transferred from one atom to another? (1) covalent (3) hydrogen (2) ionic (4) metallic 5 The elements in the Periodic Table are arranged in order of increasing (1) atomic number (2) atomic radius (3) mass number (4) neutron number 12 Which Lewis electron-dot structure is drawn correctly for the atom it represents? 6 What is the correct IUPAC name for the compound NH4Cl? (1) nitrogen chloride (2) nitrogen chlorate (3) ammonium chloride (4) ammonium chlorate P.S./Chem.–Aug. ’03 [2] (1) N (3) O (2) F (4) Ne 13 What occurs when an atom of chlorine forms a chloride ion? (1) The chlorine atom gains an electron, and its radius becomes smaller. (2) The chlorine atom gains an electron, and its radius becomes larger. (3) The chlorine atom loses an electron, and its radius becomes smaller. (4) The chlorine atom loses an electron, and its radius becomes larger. 20 At the same temperature and pressure, 1.0 liter of CO(g) and 1.0 liter of CO2(g) have (1) equal masses and the same number of molecules (2) different masses and a different number of molecules (3) equal volumes and the same number of molecules (4) different volumes and a different number of molecules 14 Which substance can not be decomposed by a chemical change? (1) Ne (3) HF (2) N2O (4) H2O 21 Which type of reaction occurs when nonmetal atoms become negative nonmetal ions? (1) oxidation (3) substitution (2) reduction (4) condensation 15 Which of these substances has the strongest intermolecular forces? (3) H2Se (1) H2O (2) H2S (4) H2Te 22 Given the reaction: H2O AgCl(s) Once equilibrium is reached, which statement is accurate? 16 A real gas behaves more like an ideal gas when the gas molecules are (1) close and have strong attractive forces between them (2) close and have weak attractive forces between them (3) far apart and have strong attractive forces between them (4) far apart and have weak attractive forces between them (1) The concentration of Ag+(aq) is greater than the concentration of Cl–(aq). (2) The AgCl(s) will be completely consumed. (3) The rates of the forward and reverse reactions are equal. (4) The entropy of the forward reaction will continue to decrease. 23 Which structural formula correctly represents a hydrocarbon molecule? H _ (1) H _H H _ C _ C __ O H (3) H _ _ C C_ H H H _ H 19 In which group of the Periodic Table do most of the elements exhibit both positive and negative oxidation states? (1) 17 (3) 12 (2) 2 (4) 7 _ (2) [3] H _ _ _ C C_ _ 18 Which of these contains only one substance? (1) distilled water (3) saltwater (2) sugar water (4) rainwater H _ H _ C_ C _ _ H H _ 17 Which phase change is an exothermic process? (1) CO2(s) → CO2(g) (3) Cu(s) → Cu() (2) NH3(g) → NH3() (4) Hg() → Hg(g) P.S./Chem.–Aug. ’03 Ag+(aq) + Cl–(aq) _ H (4) [OVER] 24 Given the structural formulas for two organic compounds: _ _ H _ _ _ _ _ H H _ _ _ and _ H O H H _ C _ C _ C _ O_ C _H H _ _ _ _ H _ H H O H _ C _ C _ C _ C _ OH H H H The differences in their physical and chemical properties are primarily due to their different (1) number of carbon atoms (3) molecular masses (2) number of hydrogen atoms (4) functional groups 28 When the pH of a solution changes from a pH of 5 to a pH of 3, the hydronium ion concentration is (1) 0.01 of the original content (2) 0.1 of the original content (3) 10 times the original content (4) 100 times the original content 25 Which structural formula represents a molecule that is not an isomer of pentane? _ H _ H H _ _ H H_ C_ C_ C_ C_H _ _ _ _ _ _ _ H _ C_ H H H H _ _ _ H H H H (1) _ _ H _ _ H H H H H _ H C _ C _ C _ C __ C __H 29 A sample of Ca(OH)2 is considered to be an Arrhenius base because it dissolves in water to yield (1) Ca2+ ions as the only positive ions in solution (2) H3O+ ions as the only positive ions in solution – (3) OH ions as the only negative ions in solution – (4) H ions as the only negative ions in solution H (3) H _ _ H_ C_ H H H _ _ _ H C C C_ H _ _ _ _ H _ C_ H H H _ H (2) H H C H H C C H H H C C H H 30 Which reaction occurs when hydrogen ions react with hydroxide ions to form water? (1) substitution (3) ionization (2) saponification (4) neutralization H (4) 26 The bonds in the compound MgSO4 can be described as (1) ionic, only (2) covalent, only (3) both ionic and covalent (4) neither ionic nor covalent 31 Which of these types of nuclear radiation has the greatest penetrating power? (1) alpha (3) neutron (2) beta (4) gamma 32 Alpha particles and beta particles differ in (1) mass, only (2) charge, only (3) both mass and charge (4) neither mass nor charge 27 Given the reaction: Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g) Which statement correctly describes what occurs when this reaction takes place in a closed system? (1) (2) (3) (4) Atoms of Zn(s) lose electrons and are oxidized. Atoms of Zn(s) gain electrons and are reduced. There is a net loss of mass. There is a net gain of mass. P.S./Chem.–Aug. ’03 [4] Note that question 35 has only three choices. 33 Given the nuclear reaction: 60 Co 27 → 0 –1e 35 In most aqueous reactions as temperature increases, the effectiveness of collisions between reacting particles (1) decreases (2) increases (3) remains the same + 60 28 Ni This reaction is an example of (1) (2) (3) (4) fission fusion artificial transmutation natural transmutation 34 As two chlorine atoms combine to form a molecule, energy is (1) absorbed (3) created (2) released (4) destroyed P.S./Chem.–Aug. ’03 [5] [OVER] Part B–1 Answer all questions in this part. Directions (36–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 41 Which equation represents a double replacement reaction? (1) 2 Na + 2 H2O → 2 NaOH + H2 (2) CaCO3 → CaO + CO2 (3) LiOH + HCl → LiCl + H2O (4) CH4 + 2 O2 → CO2 + 2 H2O 36 What is the total number of neutrons in an atom of an element that has a mass number of 19 and an atomic number of 9? (1) 9 (3) 19 (2) 10 (4) 28 37 The element in Period 4 and Group 1 of the Periodic Table would be classified as a (1) metal (3) nonmetal (2) metalloid (4) noble gas 42 What is the molecular formula of a compound that has a molecular mass of 54 and the empirical formula C2H3? (3) C6H9 (1) C2H3 (2) C4H6 (4) C8H12 38 As the elements in Period 2 of the Periodic Table are considered in succession from left to right, there is a decrease in atomic radius with increasing atomic number. This may best be explained by the fact that the (1) number of protons increases, and the number of shells of electrons remains the same (2) number of protons increases, and the number of shells of electrons increases (3) number of protons decreases, and the number of shells of electrons remains the same (4) number of protons decreases, and the number of shells of electrons increases 43 Given the diagrams X, Y, and Z below: X Y Z Key Atom of element A = 39 Given the balanced equation: Atom of element B = 2 C4H10(g) + 13 O2(g) → 8 CO2(g) + 10 H2O(g) What is the total number of moles of O2(g) that must react completely with 5.00 moles of C4H10(g)? (1) 10.0 (2) 20.0 Which diagram or diagrams represent a mixture of elements A and B? (1) X, only (2) Z, only (3) 26.5 (4) 32.5 44 Which is an electron configuration for an atom of chlorine in the excited state? (1) 2–8–7 (3) 2–8–6–1 (2) 2–8–8 (4) 2–8–7–1 40 Which particle has the same electron configuration as a potassium ion? (1) fluoride ion (3) neon atom (2) sodium ion (4) argon atom P.S./Chem.–Aug. ’03 (3) X and Y (4) X and Z [6] 45 Based on the nature of the reactants in each of the equations below, which reaction at 25°C will occur at the fastest rate? (1) C(s) + O2(g) → CO2(g) (2) NaOH(aq) + HCl(aq) → NaCl(aq) + H2O() (3) CH3OH() + CH3COOH() → CH3COOCH3(aq) + H2O() (4) CaCO3(s) → CaO(s) + CO2(g) 48 A voltaic cell differs from an electrolytic cell in that in a voltaic cell (1) energy is produced when the reaction occurs (2) energy is required for the reaction to occur (3) both oxidation and reduction occur (4) neither oxidation nor reduction occurs 49 What is the purpose of the salt bridge in a voltaic cell? (1) It blocks the flow of electrons. (2) It blocks the flow of positive and negative ions. (3) It is a path for the flow of electrons. (4) It is a path for the flow of positive and negative ions. 46 Given the reaction at equilibrium: A(g) + B(g) AB(g) + heat The concentration of A(g) can be increased by (1) (2) (3) (4) 50 According to Reference Table N, which radio1 active isotope will retain only one-eighth ( 8 ) its original radioactive atoms after approximately 43 days? (1) gold-198 (3) phosphorus-32 (2) iodine-131 (4) radon-222 lowering the temperature adding a catalyst increasing the concentration of AB(g) increasing the concentration of B(g) 47 Which structural formula represents an alcohol? H H O H C C C H H H H H C H H C C C H H H P.S./Chem.–Aug. ’03 H (3) H (2) C H (1) H O H OH H C O C H OH (4) [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–62): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 Explain how a catalyst may increase the rate of a chemical reaction. [1] 52 On the set of axes provided in your answer booklet, sketch the potential energy diagram for an endothermic chemical reaction that shows the activation energy and the potential energy of the reactants and the potential energy of the products. [2] 53 Given the reaction: Cl2 + 2 HBr → Br2 + 2 HCl Write a correctly balanced reduction half-reaction for this equation. [1] Base your answers to questions 54 and 55 on the information below. Given the unbalanced equation: ____ C6H12O6 enzyme ____ C2H5OH + ____ CO2 54 Balance the equation provided in your answer booklet, using the lowest whole-number coefficients. [1] 55 Identify the type of reaction represented. [1] Base your answers to questions 56 through 58 on the Reference Tables for Physical Setting/Chemistry. 56 Complete the data table provided in your answer booklet for the following Group 18 elements: He, Ne, Ar, Kr, Xe [1] 57 Using information from your data table in question 56, construct a line graph on the grid provided in your answer booklet, following the directions below. • Mark an appropriate scale on the axis labeled “First Ionization Energy (kJ/mol). ” [1] • Plot the data from your data table. Circle each point and connect the points. [1] Example: 58 Based on your graph in question 57, describe the trend in first ionization energy of Group 18 elements as the atomic number increases. [1] P.S./Chem.–Aug. ’03 [8] Base your answers to questions 59 through 62 on the information below. Given the heating curve where substance X starts as a solid below its melting point and is heated uniformly: F Temperature (°C) D E B C A Time (minutes) 59 Identify the process that takes place during line segment DE of the heating curve. 60 Identify a line segment in which the average kinetic energy is increasing. [1] [1] 61 Using (•) to represent particles of substance X, draw at least five particles as they would appear in the substance at point F. Use the box provided in your answer booklet. [1] 62 Describe, in terms of particle behavior or energy, what is happening to substance X during line segment BC . [1] P.S./Chem.–Aug. ’03 [9] [OVER] Part C Answer all questions in this part. Directions (63–78): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 63 and 64 on the diagram below, which shows bright-line spectra of selected elements. Bright-Line Spectra Li H He Na Unknown 63 Identify the two elements in the unknown spectrum. [2] 64 Explain how a bright-line spectrum is produced, in terms of excited state, energy transitions, and ground state. [2] 65 The table below gives information about two isotopes of element X. Isotope Mass Relative Abundance X-10 10.01 19.91% X-11 11.01 80.09% Calculate the average atomic mass of element X. • Show a correct numerical setup in the space provided in your answer booklet. • Record your answer. [1] • Express your answer to the correct number of significant figures. [1] [1] 66 A student determines the density of zinc to be 7.56 grams per milliliter. If the accepted density is 7.14 grams per milliliter, what is the student’s percent error? • Show a correct numerical setup in the space provided in your answer booklet. • Record your answer. [1] P.S./Chem.–Aug. ’03 [10] [1] Base your answers to questions 67 through 69 on the information below. Given the equation for the dissolving of sodium chloride in water: NaCl(s) H2O Na+(aq) + Cl–(aq) 67 Describe what happens to entropy during this dissolving process. [1] 68 Explain, in terms of particles, why NaCl(s) does not conduct electricity. [1] 69 When NaCl(s) is added to water in a 250-milliliter beaker, the temperature of the mixture is lower than the original temperature of the water. Describe this observation in terms of heat flow. [1] Base your answers to questions 70 through 74 on the article below, the Reference Tables for Physical Setting/Chemistry, and your knowledge of chemistry. In the 1920s, paint used to inscribe the numbers on watch dials was composed of a luminescent (glow-in-the-dark) mixture. The powdered-paint base was a mixture of radium salts and zinc sulfide. As the paint was mixed, the powdered base became airborne and drifted throughout the workroom causing the contents of the workroom, including the painters’ clothes and bodies, to glow in the dark. The paint is luminescent because radiation from the radium salts strikes a scintillator. A scintillator is a material that emits visible light in response to ionizing radiation. In watchdial paint, zinc sulfide acts as the scintillator. Radium present in the radium salts decomposes spontaneously, emitting alpha particles. These particles can cause damage to the body when they enter human tissue. Alpha particles are especially harmful to the blood, liver, lungs, and spleen because they can alter genetic information in the cells. Radium can be deposited in the bones because it substitutes for calcium. 70 Write the notation for the alpha particles emitted by radium in the radium salts. 71 How can particles emitted from radioactive nuclei damage human tissue? 72 Why does radium substitute for calcium in bones? [1] 74 Based on Reference Table F, describe the solubility of zinc sulfide in water. [11] [1] [1] 73 Explain why zinc sulfide is used in luminescent paint. P.S./Chem.–Aug. ’03 [1] [1] [OVER] Base your answers to questions 75 through 78 on the article below and on your knowledge of chemistry. Fizzies — A Splash from the Past They’re baaack . . . a splash from the past! Fizzies instant sparkling drink tablets, popular in the 1950s and 1960s, are now back on the market. What sets them apart from other powdered drinks is that they bubble and fizz when placed in water, forming an instant carbonated beverage. The fizz in Fizzies is caused by bubbles of carbon dioxide (CO2) gas that are released when the tablet is dropped into water. Careful observation reveals that these bubbles rise to the surface because CO2 gas is much less dense than water. However, not all of the CO2 gas rises to the surface; some of it dissolves in the water. The dissolved CO2 can react with water to form carbonic acid, H2CO3. H2O( ) + CO2(aq) H2CO3(aq) The pH of the Fizzies drink registers between 5 and 6, showing that the resulting solution is clearly acidic. Carbonic acid is found in other carbonated beverages as well. One of the ingredients on any soft drink label is carbonated water, which is another name for carbonic acid. However, in the production of soft drinks, the CO2 is pumped into the solution under high pressure at the bottling plant. — Brian Rohrig Excerpted from “Fizzies—A Splash from the Past,” Chem Matters, February 1998 75 What is the only positive ion in an aqueous solution of carbonic acid? [1] 76 CO2 is pumped into the soft drink solution under high pressure. Why is high pressure necessary? [1] 77 Describe the solubility of CO2 gas in water. [1] 78 Explain your response to question 77 in terms of the molecular polarities of CO2(g) and H2O(). [1] P.S./Chem.–Aug. ’03 [12] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, August 13, 2003 — 12:30 to 3:30 p.m., only Student ANSWER SHEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher .............................................. ■ Male ■ Female Grade ........... School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 13 . . . . . . . . . . . . 25 . . . . . . . . . . . 36 . . . . . . . . . . . . 44 . . . . . . . . . . . . 2 ............ 14 . . . . . . . . . . . . 26 . . . . . . . . . . . 37 . . . . . . . . . . . . 45 . . . . . . . . . . . . 3 ............ 15 . . . . . . . . . . . . 27 . . . . . . . . . . . 38 . . . . . . . . . . . . 46 . . . . . . . . . . . . 4 ............ 16 . . . . . . . . . . . . 28 . . . . . . . . . . . 39 . . . . . . . . . . . . 47 . . . . . . . . . . . . 5 ............ 17 . . . . . . . . . . . . 29 . . . . . . . . . . . 40 . . . . . . . . . . . . 48 . . . . . . . . . . . . 6 ............ 18 . . . . . . . . . . . . 30 . . . . . . . . . . . 41 . . . . . . . . . . . . 49 . . . . . . . . . . . . 7 ............ 19 . . . . . . . . . . . . 31 . . . . . . . . . . . 42 . . . . . . . . . . . . 50 . . . . . . . . . . . . 8 ............ 20 . . . . . . . . . . . . 32 . . . . . . . . . . . 43 . . . . . . . . . . . . 9 ............ 21 . . . . . . . . . . . . 33 . . . . . . . . . . . 10 . . . . . . . . . . . . 22 . . . . . . . . . . . . 34 . . . . . . . . . . . 11 . . . . . . . . . . . . 23 . . . . . . . . . . . . 35 . . . . . . . . . . . 12 . . . . . . . . . . . . 24 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Wednesday, August 13, 2003 — 12:30 to 3:30 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION A 35 B–1 15 B–2 14 C 21 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only Part B–2 51 51 Potential Energy 52 52 Reaction Coordinate [a] [OVER] For Raters Only 53 53 54 C6H12O6 enzyme C2H5OH + CO2 55 56 54 55 Atomic Number 2 10 18 36 54 Element First Ionization Energy (kJ/mol) He Ne Ar Kr Xe 56 First Ionization Energy (kJ/mol) 57 57 10 20 30 40 50 Atomic Number 58 58 [b] For Raters Only 59 59 60 60 61 61 62 62 Total Score for Part B–2 Part C 63 and 63 64 64 [c] [OVER] For Raters Only 65 65 Average atomic mass of element X: amu 66 66 % error 67 67 68 68 69 69 [d] For Raters Only 70 70 71 71 72 72 73 73 74 74 75 75 76 76 77 77 78 CO2: 78 H2O: Total Score for Part C [e] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, January 28, 2004 — 9:15 a.m. to 12:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for your use while taking this examination. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. Part A Answer all questions in this part. Directions (1–31): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 1 A neutral atom contains 11 electrons. The number atom is (1) 1 (3) (2) 11 (4) 12 neutrons and of protons in this 7 The bond between Br atoms in a Br2 molecule is (1) ionic and is formed by the sharing of two valence electrons (2) ionic and is formed by the transfer of two valence electrons (3) covalent and is formed by the sharing of two valence electrons (4) covalent and is formed by the transfer of two valence electrons 12 23 2 Isotopes of an element must have different (1) atomic numbers (2) mass numbers (3) numbers of protons (4) numbers of electrons 8 The amount of energy required to remove the outermost electron from a gaseous atom in the ground state is known as (1) first ionization energy (2) activation energy (3) conductivity (4) electronegativity 3 Which element is a noble gas? (1) krypton (3) antimony (2) chlorine (4) manganese 4 On the present Periodic Table of the Elements, the elements are arranged according to increasing (1) number of oxidation states (2) number of neutrons (3) atomic mass (4) atomic number 9 What occurs when an atom of chlorine and an atom of hydrogen become a molecule of hydrogen chloride? (1) A chemical bond is broken and energy is released. (2) A chemical bond is broken and energy is absorbed. (3) A chemical bond is formed and energy is released. (4) A chemical bond is formed and energy is absorbed. 5 What is a property of most metals? (1) They tend to gain electrons easily when bonding. (2) They tend to lose electrons easily when bonding. (3) They are poor conductors of heat. (4) They are poor conductors of electricity. 10 Which molecule is nonpolar? (1) H2O (3) CO (4) CO2 (2) NH3 6 What is the correct formula for iron (III) phosphate? (1) FeP (3) FePO4 (2) Fe3P2 (4) Fe3(PO4)2 P.S./Chem.–Jan. ’04 11 Which must be a mixture of substances? (1) solid (3) gas (2) liquid (4) solution [2] 17 Given the reaction at equilibrium: 12 A bottle of rubbing alcohol contains both 2-propanol and water. These liquids can be separated by the process of distillation because the 2-propanol and water (1) have combined chemically and retain their different boiling points (2) have combined chemically and have the same boiling point (3) have combined physically and retain their different boiling points (4) have combined physically and have the same boiling point H2(g) + Br2(g) The rate of the forward reaction is (1) (2) (3) (4) 14 Under which conditions does a real gas behave most like an ideal gas? (1) at low temperatures and high pressures (2) at low temperatures and low pressures (3) at high temperatures and high pressures (4) at high temperatures and low pressures 19 All organic compounds must contain the element (1) phosphorus (3) carbon (2) oxygen (4) nitrogen 15 What is the IUPAC name of the compound with the following structural formula? 20 Which of the following compounds has the highest boiling point? (1) H2O (3) H2Se (2) H2S (4) H2Te H O H H H C C C C H (1) propanone (2) propanal H H 21 The functional group —COOH is found in (1) esters (3) alcohols (2) aldehydes (4) organic acids (3) butanone (4) butanal 16 Which statement best explains the role of a catalyst in a chemical reaction? (1) A catalyst is added as an additional reactant and is consumed but not regenerated. (2) A catalyst limits the amount of reactants used. (3) A catalyst changes the kinds of products produced. (4) A catalyst provides an alternate reaction pathway that requires less activation energy. P.S./Chem.–Jan. ’04 greater than the rate of the reverse reaction less than the rate of the reverse reaction equal to the rate of the reverse reaction independent of the rate of the reverse reaction 18 Which statement best explains why most atomic masses on the Periodic Table are decimal numbers? (1) Atomic masses are determined relative to an H–1 standard. (2) Atomic masses are determined relative to an O–16 standard. (3) Atomic masses are a weighted average of the naturally occurring isotopes. (4) Atomic masses are an estimated average of the artificially produced isotopes. 13 Compared to pure water, an aqueous solution of calcium chloride has a (1) higher boiling point and higher freezing point (2) higher boiling point and lower freezing point (3) lower boiling point and higher freezing point (4) lower boiling point and lower freezing point H 2 HBr(g) 22 Which of these elements is the best conductor of electricity? (1) S (3) Br (2) N (4) Ni [3] [OVER] 23 Given the reaction: 2 Al(s) + Fe2O3(s) heat 28 Which equation represents a spontaneous nuclear decay? (1) C + O2 → CO2 Al2O3(s) + 2 Fe(s) Which species undergoes reduction? (1) Al (2) Fe (2) H2CO3 → CO2 + H2O + Al3 3+ (3) (4) Fe (3) (4) 24 Which energy transformation occurs when an electrolytic cell is in operation? (1) chemical energy → electrical energy (2) electrical energy → chemical energy (3) light energy → heat energy (4) light energy → chemical energy 1 + 42He → 30 15P + 0n → –10 e + 90 39 Y 29 The stability of an isotope is based on its (1) number of neutrons, only (2) number of protons, only (3) ratio of neutrons to protons (4) ratio of electrons to protons 25 Which of these pH numbers indicates the highest level of acidity? (1) 5 (3) 10 (2) 8 (4) 12 Note that questions 30 and 31 have only three choices. 30 As the temperature of a substance decreases, the average kinetic energy of its particles (1) decreases (2) increases (3) remains the same 26 According to the Arrhenius theory, when a base dissolves in water it produces – (1) CO32 as the only negative ion in solution (2) OH– as the only negative ion in solution (3) NH4+ as the only positive ion in solution (4) H+ as the only positive ion in solution 31 When an atom of phosphorus becomes a phos– phide ion (P 3 ), the radius (1) decreases (2) increases (3) remains the same 27 Which compound is an electrolyte? (3) CaCl2 (1) C6H12O6 (2) CH3OH (4) CCl4 P.S./Chem.–Jan. ’04 27 Al 13 90Sr 38 [4] Part B–1 Answer all questions in this part. Directions (32–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 32 The data table below represents the properties determined by the analysis of substances A, B, C, and D. Substance Melting Point (°C) Boiling Point (°C) A – 80 –20 none B 20 190 none C 320 770 as solid D 800 1250 in solution Conductivity Which substance is an ionic compound? (1) A (2) B (3) C (4) D 33 What is the total number of electrons in a Cr3 ion? (1) 18 (3) 24 (2) 21 (4) 27 + 36 What is the empirical formula of a compound with the molecular formula N2O4? (1) NO (3) N2O (2) NO2 (4) N2O3 34 As the atoms of the Group 17 elements in the ground state are considered from top to bottom, each successive element has (1) the same number of valence electrons and similar chemical properties (2) the same number of valence electrons and identical chemical properties (3) an increasing number of valence electrons and similar chemical properties (4) an increasing number of valence electrons and identical chemical properties 37 What is the correct Lewis electron-dot structure for the compound magnesium fluoride? • • •• Mg F •• • • • • •• (1) •• Mg+ •• F •• − •• (3) − •• (2) 35 Which solution when mixed with a drop of bromthymol blue will cause the indicator to change from blue to yellow? (1) 0.1 M HCl (3) 0.1 M CH3OH (2) 0.1 M NH3 (4) 0.1 M NaOH − + •• F •• Mg2 •• F •• •• • • •• •• •• •• •• •• F •• Mg •• F •• (4) 38 Given the reaction: Mg(s) + 2 AgNO3(aq) → Mg(NO3)2(aq) + 2 Ag(s) Which type of reaction is represented? (1) single replacement (3) synthesis (2) double replacement (4) decomposition P.S./Chem.–Jan. ’04 [5] [OVER] 43 Given the equation: 39 Which equation shows conservation of both mass and charge? (1) Cl2 + Br – → Cl – + Br2 + (2) Cu + 2 Ag + → Cu2 + Ag + + (3) Zn + Cr 3 → Zn2 + Cr + + (4) Ni + Pb2 → Ni2 + Pb C2H6 + Cl2 → C2H5Cl + HCl This reaction is best described as (1) addition involving a saturated hydrocarbon (2) addition involving an unsaturated hydrocarbon (3) substitution involving a saturated hydrocarbon (4) substitution involving an unsaturated hydrocarbon 40 The volume of a gas is 4.00 liters at 293 K and constant pressure. For the volume of the gas to become 3.00 liters, the Kelvin temperature must be equal to (1) 3.00 × 293 4.00 (3) 3.00 × 4.00 293 (2) 4.00 × 293 3.00 293 (4) 3.00 × 4.00 44 The diagram below shows a key being plated with copper in an electrolytic cell. + 41 What is the molarity of a solution containing 20 grams of NaOH in 500 milliliters of solution? (1) 1 M (3) 0.04 M (2) 2 M (4) 0.5 M – A B CuSO4(aq) Copper electrode 42 Which graph best represents the pressurevolume relationship for an ideal gas at constant temperature? Battery Given the reduction reaction for this cell: + Cu2 (aq) + 2e– → Cu(s) This reduction occurs at V P P (1) (3) V P.S./Chem.–Jan. ’04 (1) (2) (3) (4) V A, which is the anode A, which is the cathode B, which is the anode B, which is the cathode 45 A student neutralized 16.4 milliliters of HCl by adding 12.7 milliliters of 0.620 M KOH. What was the molarity of the HCl acid? (1) 0.168 M (3) 0.620 M (2) 0.480 M (4) 0.801 M V P P (2) (4) 46 Nuclear fusion differs from nuclear fission because nuclear fusion reactions (1) form heavier isotopes from lighter isotopes (2) form lighter isotopes from heavier isotopes (3) convert mass to energy (4) convert energy to mass [6] 50 Given the equation: 47 After 32 days, 5 milligrams of an 80-milligram sample of a radioactive isotope remains unchanged. What is the half-life of this element? (1) 8 days (3) 16 days (2) 2 days (4) 4 days KNO3(s) H2O() KNO3(aq) As H2O() is added toKNO3(s) to form KNO3(aq), the entropy of the system 48 Which electron configuration represents an atom of chlorine in an excited state? (1) 2–8–7 (3) 2–8–6–1 (2) 2–8–8 (4) 2–8–7–1 (1) decreases (2) increases (3) remains the same Note that questions 49 and 50 have only three choices. 49 As each successive element in Group 15 of the Periodic Table is considered in order of increasing atomic number, the atomic radius (1) decreases (2) increases (3) remains the same P.S./Chem.–Jan. ’04 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–62): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 and 52 on the unbalanced equation provided in your answer booklet. 51 Balance the equation in your answer booklet, using the smallest whole-number coefficients. [1] 52 a Using your balanced equation, show a correct numerical setup for calculating the total number of moles of H2O(g) produced when 5.0 moles of O2(g) are completely consumed. Use the space provided in your answer booklet. [1] b Record your answer. [1] Base your answers to questions 53 through 55 on the data table provided in your answer booklet. 53 In your answer booklet, record the electronegativity for the elements with atomic numbers 11 through 17. [1] 54 On the grid provided in your answer booklet, mark an appropriate scale on the axis labeled “Electronegativity.” [1] 55 On the same grid, plot the data from the data table. Circle and connect the points. [1] Example: P.S./Chem.–Jan. ’04 [8] Base your answers to questions 56 through 58 on the information below. A student uses 200 grams of water at a temperature of 60°C to prepare a saturated solution of potassium chloride, KCl. 56 Identify the solute in this solution. [1] 57 According to Reference Table G, how many grams of KCl must be used to create this saturated solution? [1] 58 This solution is cooled to 10°C and the excess KCl precipitates (settles out). The resulting solution is saturated at 10°C. How many grams of KCl precipitated out of the original solution? [1] Base your answers to questions 59 through 61 on the diagram of the voltaic cell below. Voltaic Cell V Voltmeter Wire Switch Salt bridge Pb(s) electrode 2+ Ag(s) electrode + Pb (aq) Ag (aq) Half-cell 1 Half-cell 2 + 2+ 2 Ag (aq) + Pb(s) Pb (aq) + 2 Ag(s) 59 When the switch is closed, in which half-cell does oxidation occur? [1] 60 When the switch is closed, state the direction that electrons will flow through the wire. [1] 61 Based on the given equation, write the balanced half-reaction that occurs in half-cell 1. [1] 62 In the space provided in your answer booklet, draw a Lewis electron-dot structure for an atom of phosphorus. [1] P.S./Chem.–Jan. ’04 [9] [OVER] Part C Answer all questions in this part. Directions (63–81): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 63 and 64 on the information and the bright-line spectra represented below. Many advertising signs depend on the production of light emissions from gas-filled glass tubes that are subjected to a high-voltage source. When light emissions are passed through a spectroscope, bright-line spectra are produced. Gas A Gas B Gas C Gas D Unknown mixture 63 Identify the two gases in the unknown mixture. [2] 64 Explain the production of an emission spectrum in terms of the energy states of an electron. [1] P.S./Chem.–Jan. ’04 [10] Base your answers to questions 65 through 67 on the particle diagrams below, which show atoms and/or molecules in three different samples of matter at STP. Key atom of x atom of y atom of z Sample 1 Sample 2 65 Which sample represents a pure substance? Sample 3 [1] 66 When two atoms of y react with one atom of z, a compound forms. Using the number of atoms shown in sample 2, what is the maximum number of molecules of this compound that can be formed? [1] 67 Explain why x x does not represent a compound. [1] Base your answers to questions 68 through 70 on the information below. Many artificial flavorings are prepared using the type of organic reaction shown below. H O H C C H H H OH H Reactant 1 H O + HO C C C H H H H H C C O C C C H + H H H H HOH H H H Reactant 2 68 What is the name of this organic reaction? [1] 69 To what class of organic compounds does reactant 2 belong? [1] 70 In the space provided in your answer booklet, draw the structural formula of an isomer of reactant 2. [1] P.S./Chem.–Jan. ’04 [11] [OVER] Base your answers to questions 71 through 74 on the article below, the Reference Tables for Physical Setting/Chemistry, and your knowledge of chemistry. Radioactivity at home You may be surprised to learn that you do not need to visit a nuclear power plant or a hospital X-ray laboratory to find sources of radioactivity. They are all around us. In fact, it is likely that you’ll find a few at home. Your front porch may incorporate cinder blocks or granite blocks. Both contain uranium. Walk through the front door, look up, and you’ll see a smoke detector that owes its effectiveness to the constant source of alpha particle emissions from Americium-241. As long as the gases remain ionized within the shielded container, electricity flows, and all is calm. When smoke enters the chamber, it neutralizes the charges on these ions. In the absence of these ions, the circuit breaks and the alarm goes off. Indicator lights on your appliances may use Krypton-85; electric blankets, promethium147; and fluorescent lights, thorium-229. Even the food we eat is radioactive. The more potassium-rich the food source, the more potassium-40—a radioactive isotope that makes up about 0.01% of the natural supply of this mineral—is present. Thus, brazil nuts, peanuts, bananas, potatoes, and flour, all rich in potassium, are radiation sources. —Chem Matters April 2000 71 Write the equation for the alpha decay that occurs in a smoke detector containing Americium-241 (Am-241). [2] 72 How is the radioactive decay of Krypton-85 different from the radioactive decay of Americium-241? [1] 73 State one benefit or useful application of radioactivity not mentioned in this article. [1] 74 State one risk or danger associated with radioactivity. [1] Base your answers to questions 75 and 76 on the information below. Gypsum is a mineral that is used in the construction industry to make drywall (sheetrock). The chemical formula for this hydrated compound is CaSO4 • 2 H2O. A hydrated compound contains water molecules within its crystalline structure. Gypsum contains 2 moles of water for each 1 mole of calcium sulfate. 75 What is the gram formula mass of CaSO4 • 2 H2O? [1] 76 a In the space provided in your answer booklet, show a correct numerical setup for calculating the percent composition by mass of water in this compound. [1] b Record your answer. [1] P.S./Chem.–Jan. ’04 [12] Base your answers to questions 77 through 79 on the information and potential energy diagram below. Potential Energy Chemical cold packs are often used to reduce swelling after an athletic injury. The diagram represents the potential energy changes when a cold pack is activated. C A B D Reaction Coordinate 77 Which lettered interval on the diagram represents the potential energy of the products? [1] 78 Which lettered interval on the diagram represents the heat of reaction? [1] 79 Identify a reactant listed in Reference Table I that could be mixed with water for use in a chemical cold pack. [1] Base your answers to questions 80 and 81 on the information below. Calcium hydroxide is commonly known as agricultural lime and is used to adjust the soil pH. Before the lime was added to a field, the soil pH was 5. After the lime was added, the soil underwent a 100-fold decrease in hydronium ion concentration. 80 What is the new pH of the soil in the field? [1] 81 According to Reference Table F, calcium hydroxide is soluble in water. Identify another hydroxide compound that contains a Group 2 element and is also soluble in water. [1] P.S./Chem.–Jan. ’04 [13] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, January 28, 2004 — 9:15 a.m. to 12:15 p.m., only Student ANSWER SHEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher .............................................. ■ Male ■ Female Grade ........... School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 12 . . . . . . . . . . . . 23 . . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 2 ............ 13 . . . . . . . . . . . . 24 . . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 3 ............ 14 . . . . . . . . . . . . 25 . . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 4 ............ 15 . . . . . . . . . . . . 26 . . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 5 ............ 16 . . . . . . . . . . . . 27 . . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 6 ............ 17 . . . . . . . . . . . . 28 . . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 7 ............ 18 . . . . . . . . . . . . 29 . . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 8 ............ 19 . . . . . . . . . . . . 30 . . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 9 ............ 20 . . . . . . . . . . . . 31 . . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part A Score 10 . . . . . . . . . . . . 21 . . . . . . . . . . . . 11 . . . . . . . . . . . . 22 . . . . . . . . . . . . Part B–1 Score 41 . . . . . . . . . . . . Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Wednesday, January 28, 2004 — 9:15 a.m. to 12:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION A 31 B–1 19 B–2 13 C 22 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only Part B–2 51 __________ C5H12(g) + __________ O2(g) → __________ CO2(g) + __________H2O(g) 51 52 a 52a b ______________ mol H2O b [1] [OVER] For Raters Only 53 Atomic Number Electronegativity 11 12 13 53 14 15 16 17 Electronegativity 54 and 55 54 55 11 12 13 14 15 16 17 Atomic Number [2] For Raters Only 56 56 57 grams 57 58 grams 58 59 59 60 60 61 61 62 62 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 63 ____________________________ and ___________________________ 63 64 64 65 _______________ 65 66 _______________ 66 67 67 68 68 69 69 70 70 [4] For Raters Only 71 71 72 72 73 73 74 74 75 75 _______________ g/mol 76 a 76a b _____________ % b [5] [OVER] For Raters Only 77 _______________ 77 78 _______________ 78 79 79 80 _______________ 80 81 81 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 23, 2004 — 9:15 a.m. to 12:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for your use while taking this examination. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–33): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 Given the reaction: N2(g) + 3 H2(g) 1 The modern model of the atom is based on the work of (1) one scientist over a short period of time (2) one scientist over a long period of time (3) many scientists over a short period of time (4) many scientists over a long period of time What is the mole-to-mole ratio between nitrogen gas and hydrogen gas? (1) 1:2 (2) 1:3 2 Which statement is true about the charges assigned to an electron and a proton? (1) Both an electron and a proton are positive. (2) An electron is positive and a proton is negative. (3) An electron is negative and a proton is positive. (4) Both an electron and a proton are negative. (3) 2:2 (4) 2:3 8 What is the percent by mass of oxygen in propanal, CH3CH2CHO? (1) 10.0% (3) 38.1% (2) 27.6% (4) 62.1% 9 Covalent bonds are formed when electrons are (1) transferred from one atom to another (2) captured by the nucleus (3) mobile within a metal (4) shared between two atoms 3 In the wave-mechanical model, an orbital is a region of space in an atom where there is (1) a high probability of finding an electron (2) a high probability of finding a neutron (3) a circular path in which electrons are found (4) a circular path in which neutrons are found 10 Which type of molecule is CF4? (1) polar, with a symmetrical distribution of charge (2) polar, with an asymmetrical distribution of charge (3) nonpolar, with a symmetrical distribution of charge (4) nonpolar, with an asymmetrical distribution of charge 4 What is the charge of the nucleus in an atom of oxygen-17? (1) 0 (3) +8 (2) –2 (4) +17 5 Which pair of symbols represents a metalloid and a noble gas? (1) Si and Bi (3) Ge and Te (2) As and Ar (4) Ne and Xe 11 Which change occurs when a barium atom loses two electrons? (1) It becomes a negative ion and its radius decreases. (2) It becomes a negative ion and its radius increases. (3) It becomes a positive ion and its radius decreases. (4) It becomes a positive ion and its radius increases. 6 Which statement describes a chemical property of iron? (1) Iron can be flattened into sheets. (2) Iron conducts electricity and heat. (3) Iron combines with oxygen to form rust. (4) Iron can be drawn into a wire. P.S./Chem.–June ’04 2 NH3(g) [2] 18 Which sample contains particles in a rigid, fixed, geometric pattern? (1) CO2(aq) (3) H2O() (2) HCl(g) (4) KCl(s) 12 Conductivity in a metal results from the metal atoms having (1) high electronegativity (2) high ionization energy (3) highly mobile protons in the nucleus (4) highly mobile electrons in the valence shell 19 Given the reaction at 25°C: Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g) 13 Which of these elements has the least attraction for electrons in a chemical bond? (1) oxygen (3) nitrogen (2) fluorine (4) chlorine The rate of this reaction can be increased by using 5.0 grams of powdered zinc instead of a 5.0-gram strip of zinc because the powdered zinc has (1) (2) (3) (4) 14 Recovering the salt from a mixture of salt and water could best be accomplished by (1) evaporation (2) filtration (3) paper chromatography (4) density determination 20 Which statement about a system at equilibrium is true? (1) The forward reaction rate is less than the reverse reaction rate. (2) The forward reaction rate is greater than the reverse reaction rate. (3) The forward reaction rate is equal to the reverse reaction rate. (4) The forward reaction rate stops and the reverse reaction rate continues. 15 The average kinetic energy of water molecules is greatest in which of these samples? (1) 10 g of water at 35°C (2) 10 g of water at 55°C (3) 100 g of water at 25°C (4) 100 g of water at 45°C 16 Helium is most likely to behave as an ideal gas when it is under (1) high pressure and high temperature (2) high pressure and low temperature (3) low pressure and high temperature (4) low pressure and low temperature 21 A catalyst increases the rate of a chemical reaction by (1) lowering the activation energy of the reaction (2) lowering the potential energy of the products (3) raising the temperature of the reactants (4) raising the concentration of the reactants 17 At STP, the element oxygen can exist as either O2 or O3 gas molecules. These two forms of the element have (1) the same chemical and physical properties (2) the same chemical properties and different physical properties (3) different chemical properties and the same physical properties (4) different chemical and physical properties P.S./Chem.–June ’04 lower kinetic energy lower concentration more surface area more zinc atoms 22 Which element must be present in an organic compound? (1) hydrogen (3) carbon (2) oxygen (4) nitrogen 23 Which compound is a saturated hydrocarbon? (1) hexane (3) hexanol (2) hexene (4) hexanal [3] [OVER] 24 Given the reaction: O O CH3C—O—C2H5 + H2O CH3C— OH + HOC2H5 This reaction is an example of (1) fermentation (2) saponification (3) hydrogenation (4) esterification 25 Which of these compounds has chemical properties most similar to the chemical properties of ethanoic acid? (1) C3H7COOH (3) C2H5COOC2H5 (2) C2H5OH (4) C2H5OC2H5 30 Which compound could serve as a reactant in a neutralization reaction? (1) NaCl (3) CH3OH (2) KOH (4) CH3CHO 31 Which of these particles has the greatest mass? (1) alpha (3) neutron (2) beta (4) positron 26 Given the reaction that occurs in an electrochemical cell: Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s) During this reaction, the oxidation number of Zn changes from (1) 0 to +2 (2) 0 to –2 32 In a nuclear fusion reaction, the mass of the products is (1) less than the mass of the reactants because some of the mass has been converted to energy (2) less than the mass of the reactants because some of the energy has been converted to mass (3) more than the mass of the reactants because some of the mass has been converted to energy (4) more than the mass of the reactants because some of the energy has been converted to mass (3) +2 to 0 (4) –2 to 0 27 A voltaic cell spontaneously converts (1) electrical energy to chemical energy (2) chemical energy to electrical energy (3) electrical energy to nuclear energy (4) nuclear energy to electrical energy 28 Which pair of formulas represents two compounds that are electrolytes? (1) HCl and CH3OH (2) HCl and NaOH (3) C5H12 and CH3OH (4) C5H12 and NaOH 33 Which of these types of radiation has the greatest penetrating power? (1) alpha (3) gamma (2) beta (4) positron 29 Hydrogen chloride, HCl, is classified as an Arrhenius acid because it produces (1) H+ ions in aqueous solution (2) Cl– ions in aqueous solution (3) OH– ions in aqueous solution (4) NH4+ ions in aqueous solution P.S./Chem.–June ’04 [4] Part B–1 Answer all questions in this part. Directions (34–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 40 The graph below represents the uniform heating of a substance, starting with the substance as a solid below its melting point. Temperature 34 How many electrons are contained in an Au3+ ion? (1) 76 (3) 82 (2) 79 (4) 197 35 Which electron configuration represents the electrons of an atom in an excited state? (1) 2–4 (3) 2–7–2 (2) 2–6 (4) 2–8–2 36 In comparison to an atom of 199 F in the ground state, an atom of 126 C in the ground state has (1) three fewer neutrons (2) three fewer valence electrons (3) three more neutrons (4) three more valence electrons E D B C A Time Which line segment represents an increase in potential energy and no change in average kinetic energy? (1) AB (2) BC 37 Element X is a solid that is brittle, lacks luster, and has six valence electrons. In which group on the Periodic Table would element X be found? (1) 1 (3) 15 (2) 2 (4) 16 (3) CD (4) EF 41 Using your knowledge of chemistry and the information in Reference Table H, which statement concerning propanone and water at 50°C is true? (1) Propanone has a higher vapor pressure and stronger intermolecular forces than water. (2) Propanone has a higher vapor pressure and weaker intermolecular forces than water. (3) Propanone has a lower vapor pressure and stronger intermolecular forces than water. (4) Propanone has a lower vapor pressure and weaker intermolecular forces than water. 38 What is the empirical formula for the compound C6H12O6? (3) C3H6O3 (1) CH2O (2) C2H4O2 (4) C6H12O6 39 The bonds between hydrogen and oxygen in a water molecule are classified as (1) polar covalent (2) nonpolar covalent (3) ionic (4) metallic P.S./Chem.–June ’04 F 42 A solution that is at equilibrium must be (1) concentrated (3) saturated (2) dilute (4) unsaturated [5] [OVER] 43 Given the reaction: N2(g) + O2(g) + 182.6 kJ 47 Which structural formula represents an ether? 2 NO(g) Which change would cause an immediate increase in the rate of the forward reaction? (1) (2) (3) (4) H H H H C C C C H H H C H H H H C C H H (1) (1) (2) (3) (4) H H H C C H C H H H H H (2) P.S./Chem.–June ’04 C H H H O C C OH (3) H OH H C H O H C H H (4) C C Al + 3e– → Al3+ Al → Al3+ + 3e– O2 + 4e– → 2 O2– O2 → 2 O2– + 4e– 49 Based on Reference Table N, what fraction of a sample of gold-198 remains radioactive after 2.69 days? (1) 14 (3) 34 C H H H (2) H H C C Which half-reaction correctly represents the oxidation that occurs? (3) C H 48 Given the reaction for the corrosion of aluminum: 4 Al + 3 O2 → 2 Al2O3 H H H H H H (2) 46 Which structural formula represents 2-pentyne? H C H 45 Which pH indicates a basic solution? (1) 1 (3) 7 (2) 5 (4) 12 H C H (1) H2O(g) at 120°C H2O() at 80°C H2O() at 20°C H2O(s) at 0°C H O H increasing the concentration of NO(g) increasing the concentration of N2(g) decreasing the reaction temperature decreasing the reaction pressure 44 Which 10-milliliter sample of water has the greatest degree of disorder? (1) (2) (3) (4) H 1 2 (4) 7 8 Note that question 50 has only three choices. H H H H C C C H H H C C H H 50 As the elements of Group 1 on the Periodic Table are considered in order of increasing atomic radius, the ionization energy of each successive element generally (1) decreases (2) increases (3) remains the same H (4) [6] Part B–2 Answer all questions in this part. Directions (51–64): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 through 53 on the balanced chemical equation below. 2 H2O → 2 H2 + O2 51 What type of reaction does this equation represent? [1] 52 How does the balanced chemical equation show the Law of Conservation of Mass? [1] 53 What is the total number of moles of O2 produced when 8 moles of H2O is completely consumed? [1] Base your answers to questions 54 and 55 on the unbalanced redox reaction below. Cu(s) + AgNO3(aq) → Cu(NO3)2(aq) + Ag(s) 54 Write the reduction half-reaction. [1] 55 Balance the redox equation in your answer booklet, using the smallest whole-number coefficients. [1] Base your answers to questions 56 through 58 on the information below. A student titrates 60.0 mL of HNO3(aq) with 0.30 M NaOH(aq). Phenolphthalein is used as the indicator. After adding 42.2 mL of NaOH(aq), a color change remains for 25 seconds, and the student stops the titration. 56 What color change does phenolphthalein undergo during this titration? [1] 57 In the space provided in your answer booklet, show a correct numerical setup for calculating the molarity of the HNO3(aq). [1] 58 According to the data, how many significant figures should be present in the calculated molarity of the HNO3(aq)? [1] P.S./Chem.–June ’04 [7] [OVER] Base your answers to questions 59 through 61 on the data table below, which shows three isotopes of neon. Isotope Atomic Mass Percent Natural (atomic mass units) Abundance 20Ne 19.99 90.9% 21Ne 20.99 0.3% 22Ne 21.99 8.8% 59 In terms of atomic particles, state one difference between these three isotopes of neon. [1] 60 Based on the atomic masses and the natural abundances shown in the data table, in the space provided in your answer booklet, show a correct numerical setup for calculating the average atomic mass of neon. [1] 61 Based on natural abundances, the average atomic mass of neon is closest to which whole number? [1] 62 Based on the Periodic Table, explain why Na and K have similar chemical properties. [1] 63 In the space to the right of the reactants and arrow provided in your answer booklet, draw the structural formula for the product of the reaction shown. [1] 64 Given the nuclear equation: 58 Cu 29 → 58 28 Ni + X What nuclear particle is represented by X? P.S./Chem.–June ’04 [8] [1] Part C Answer all questions in this part. Directions (65–85): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 65 through 67 on the information and equation below. Antacids can be used to neutralize excess stomach acid. Brand A antacid contains the acidneutralizing agent magnesium hydroxide, Mg(OH)2. It reacts with HCl(aq) in the stomach, according to the following balanced equation: 2 HCl(aq) + Mg(OH)2(s) → MgCl2(aq) + 2 H2O() 65 In the space provided in your answer booklet, show a correct numerical setup for calculating the number of moles of Mg(OH)2 (gram-formula mass = 58.3 grams/mole) in an 8.40-gram sample. [1] 66 If a person produces 0.050 mole of excess HCl in the stomach, how many moles of Mg(OH)2 are needed to neutralize this excess hydrochloric acid? [1] 67 Brand B antacid contains the acid-neutralizing agent sodium hydrogen carbonate. Write the chemical formula for sodium hydrogen carbonate. [1] Base your answers to questions 68 through 70 on the information below. Naphthalene, a nonpolar substance that sublimes at room temperature, can be used to protect wool clothing from being eaten by moths. 68 Explain, in terms of intermolecular forces, why naphthalene sublimes. 69 Explain why naphthalene is not expected to dissolve in water. [1] [1] 70 The empirical formula for naphthalene is C5H4 and the molecular mass of naphthalene is 128 grams/mole. What is the molecular formula for naphthalene? [1] P.S./Chem.–June ’04 [9] [OVER] Base your answers to questions 71 through 74 on the data table below, which shows the solubility of a solid solute. The Solubility of the Solute at Various Temperatures Solute per Temperature 100 g of H2O(g) (°C) 0 18 20 20 40 24 60 29 80 36 100 49 71 On the grid provided in your answer booklet, mark an appropriate scale on the axis labeled “Solute per 100 g of H2O(g).” An appropriate scale is one that allows a trend to be seen. [1] 72 On the same grid, plot the data from the data table. Circle and connect the points. [1] Example: 73 Based on the data table, if 15 grams of solute is dissolved in 100 grams of water at 40°C, how many more grams of solute can be dissolved in this solution to make it saturated at 40°C? [1] 74 According to Reference Table G, how many grams of KClO3 must be dissolved in 100 grams of H2O at 10°C to produce a saturated solution? [1] Base your answers to questions 75 through 78 on the information below. A weather balloon has a volume of 52.5 liters at a temperature of 295 K. The balloon is released and rises to an altitude where the temperature is 252 K. 75 How does this temperature change affect the gas particle motion? [1] 76 The original pressure at 295 K was 100.8 kPa and the pressure at the higher altitude at 252 K is 45.6 kPa. Assume the balloon does not burst. In the space provided in your answer booklet, show a correct numerical setup for calculating the volume of the balloon at the higher altitude. [1] 77 What Celsius temperature is equal to 252 K? [1] 78 What pressure, in atmospheres (atm), is equal to 45.6 kPa? [1] P.S./Chem.–June ’04 [10] Base your answers to questions 79 and 80 on the information and equation below. Human blood contains dissolved carbonic acid, H2CO3, in equilibrium with carbon dioxide and water. The equilibrium system is shown below. H2CO3(aq) CO2(aq) + H2O() 79 Explain, using LeChatelier’s principle, why decreasing the concentration of CO2 decreases the concentration of H2CO3. [1] 80 What is the oxidation number of carbon in H2CO3(aq)? [1] Base your answers to questions 81 through 84 on the information below. A safe level of fluoride ions is added to many public drinking water supplies. Fluoride ions have been found to help prevent tooth decay. Another common source of fluoride ions is toothpaste. One of the fluoride compounds used in toothpaste is tin(II) fluoride. A town located downstream from a chemical plant was concerned about fluoride ions from the plant leaking into its drinking water. According to the Environmental Protection Agency, the fluoride ion concentration in drinking water cannot exceed 4 ppm. The town hired a chemist to analyze its water. The chemist determined that a 175-gram sample of the town’s water contains 0.000 250 gram of fluoride ions. 81 In the box provided in your answer booklet, draw a Lewis electron-dot diagram for a fluoride ion. [1] 82 What is the chemical formula for tin(II) fluoride? [1] 83 How many parts per million of fluoride ions are present in the analyzed sample? [1] 84 Is the town’s drinking water safe to drink? Support your decision using information in the passage and your calculated fluoride level in question 83. [1] 85 A plan is being developed for an experiment to test the effect of concentrated strong acids on a metal surface protected by various coatings. Some safety precautions would be the wearing of chemical safety goggles, an apron, and gloves. State one additional safety precaution that should be included in the plan. [1] P.S./Chem.–June ’04 [11] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, June 23, 2004 — 9:15 a.m. to 12:15 p.m., only ANSWER SHEET ■ Male ■ Female Grade Student .............................................. Sex: ........... Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 12 . . . . . . . . . . . . 23 . . . . . . . . . . . 34 . . . . . . . . . . . . 43 . . . . . . . . . . . . 2 ............ 13 . . . . . . . . . . . . 24 . . . . . . . . . . . 35 . . . . . . . . . . . . 44 . . . . . . . . . . . . 3 ............ 14 . . . . . . . . . . . . 25 . . . . . . . . . . . 36 . . . . . . . . . . . . 45 . . . . . . . . . . . . 4 ............ 15 . . . . . . . . . . . . 26 . . . . . . . . . . . 37 . . . . . . . . . . . . 46 . . . . . . . . . . . . 5 ............ 16 . . . . . . . . . . . . 27 . . . . . . . . . . . 38 . . . . . . . . . . . . 47 . . . . . . . . . . . . 6 ............ 17 . . . . . . . . . . . . 28 . . . . . . . . . . . 39 . . . . . . . . . . . . 48 . . . . . . . . . . . . 7 ............ 18 . . . . . . . . . . . . 29 . . . . . . . . . . . 40 . . . . . . . . . . . . 49 . . . . . . . . . . . . 8 ............ 19 . . . . . . . . . . . . 30 . . . . . . . . . . . 41 . . . . . . . . . . . . 50 . . . . . . . . . . . . 9 ............ 20 . . . . . . . . . . . . 31 . . . . . . . . . . . 42 . . . . . . . . . . . . 10 . . . . . . . . . . . . 21 . . . . . . . . . . . . 32 . . . . . . . . . . . 11 . . . . . . . . . . . . 22 . . . . . . . . . . . . 33 . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Wednesday, June 23, 2004 — 9:15 a.m. to 12:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION A 33 B–1 17 B–2 14 C 21 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only Part B–2 51 51 52 52 53 mol 53 54 54 55 _______ Cu(s) + _______ AgNO3(aq) → _______ Cu(NO3)2(aq) + _______ Ag(s) 55 [1] [OVER] For Raters Only 56 to 56 57 57 58 58 59 59 60 60 61 61 [2] For Raters Only 62 62 63 H H H H H C C C C H 63 H + Br2 H 64 64 Total Score for Part B–2 Part C 65 65 66 66 mol 67 67 [3] [OVER] For Raters Only 68 68 69 69 70 70 [4] For Raters Only 71 and 72 Solute per 100 g of H2O(g) Solubility Curve 71 72 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C) 73 g 73 74 g 74 [5] [OVER] For Raters Only 75 75 76 76 77 °C 77 78 atm 78 79 79 80 80 [6] For Raters Only 81 81 82 83 82 ppm 83 84 84 85 85 Total Score for Part C [7] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Tuesday, August 17, 2004 — 12:30 to 3:30 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–33): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 1 Which of these phrases best describes an atom? (1) a positive nucleus surrounded by a hard negative shell (2) a positive nucleus surrounded by a cloud of negative charges (3) a hard sphere with positive particles uniformly embedded (4) a hard sphere with negative particles uniformly embedded 6 At 298 K, oxygen (O2) and ozone (O3) have different properties because their (1) atoms have different atomic numbers (2) atoms have different atomic masses (3) molecules have different molecular structures (4) molecules have different average kinetic energies 7 Which substance represents a compound? (1) C(s) (3) CO(g) (2) Co(s) (4) O2(g) 2 Which statement is true about a proton and an electron? (1) They have the same masses and the same charges. (2) They have the same masses and different charges. (3) They have different masses and the same charges. (4) They have different masses and different charges. 8 All chemical reactions have a conservation of (1) mass, only (2) mass and charge, only (3) charge and energy, only (4) mass, charge, and energy 9 Which characteristic is a property of molecular substances? (1) good heat conductivity (2) good electrical conductivity (3) low melting point (4) high melting point 3 The atomic mass of an element is the weighted average of the masses of (1) its two most abundant isotopes (2) its two least abundant isotopes (3) all of its naturally occurring isotopes (4) all of its radioactive isotopes 10 Given the Lewis electron-dot diagram: H 4 What determines the order of placement of the elements on the modern Periodic Table? (1) atomic number (2) atomic mass (3) the number of neutrons, only (4) the number of neutrons and protons H C H H Which electrons are represented by all of the dots? (1) (2) (3) (4) 5 Which compound contains only covalent bonds? (1) NaOH (3) Ca(OH)2 (2) Ba(OH)2 (4) CH3OH P.S./Chem.–Aug. ’04 [2] the carbon valence electrons, only the hydrogen valence electrons, only the carbon and hydrogen valence electrons all of the carbon and hydrogen electrons 11 Which grouping of the three phases of bromine is listed in order from left to right for increasing distance between bromine molecules? (1) gas, liquid, solid (3) solid, gas, liquid (2) liquid, solid, gas (4) solid, liquid, gas 17 Which process represents a chemical change? (1) melting of ice (2) corrosion of copper (3) evaporation of water (4) crystallization of sugar 12 Which statement concerning elements is true? (1) Different elements must have different numbers of isotopes. (2) Different elements must have different numbers of neutrons. (3) All atoms of a given element must have the same mass number. (4) All atoms of a given element must have the same atomic number. 18 At STP, which 4.0-gram zinc sample will react fastest with dilute hydrochloric acid? (1) lump (3) powdered (2) bar (4) sheet metal 13 At room temperature, solute in water would change in pressure? (1) methanol (2) sugar 19 Which information about a chemical reaction is provided by a potential energy diagram? (1) the oxidation states of the reactants and products (2) the average kinetic energy of the reactants and products (3) the change in solubility of the reacting substances (4) the energy released or absorbed during the reaction the solubility of which be most affected by a (3) carbon dioxide (4) sodium nitrate 20 A catalyst works by (1) increasing the potential energy of the reactants (2) increasing the energy released during a reaction (3) decreasing the potential energy of the products (4) decreasing the activation energy required for a reaction 14 Based on Reference Table I, which change occurs when pellets of solid NaOH are added to water and stirred? (1) The water temperature increases as chemical energy is converted to heat energy. (2) The water temperature increases as heat energy is stored as chemical energy. (3) The water temperature decreases as chemical energy is converted to heat energy. (4) The water temperature decreases as heat energy is stored as chemical energy. 21 Even though the process is endothermic, snow can sublime. Which tendency in nature accounts for this phase change? (1) a tendency toward greater entropy (2) a tendency toward greater energy (3) a tendency toward less entropy (4) a tendency toward less energy 15 The concept of an ideal gas is used to explain (1) the mass of a gas sample (2) the behavior of a gas sample (3) why some gases are monatomic (4) why some gases are diatomic 22 What is the IUPAC name of the compound with the structural formula shown below? 16 Molecules in a sample of NH3() are held closely together by intermolecular forces (1) existing between ions (2) existing between electrons (3) caused by different numbers of neutrons (4) caused by unequal charge distribution P.S./Chem.–Aug. ’04 H H H H C C C H H (1) 2-pentene (2) 3-pentene [3] H C C H H H (3) 2-pentyne (4) 3-pentyne [OVER] 23 Molecules of 1-bromopropane and 2-bromopropane differ in (1) molecular formula (2) structural formula (3) number of carbon atoms per molecule (4) number of bromine atoms per molecule 28 The only positive ion found in an aqueous solution of sulfuric acid is the (1) hydroxide ion (3) sulfite ion (2) hydronium ion (4) sulfate ion 29 Which process uses a volume of solution of known concentration to determine the concentration of another solution? (1) distillation (3) transmutation (2) substitution (4) titration 24 Which half-reaction correctly represents reduction? 3+ – (1) Ag → Ag+ + e– (3) Au + 3e → Au 2+ – 3+ (2) F2 → 2 F – + 2e– (4) Fe + e → Fe 30 Which pH change represents a hundredfold increase in the concentration of H3O+? (1) pH 5 to pH 7 (3) pH 3 to pH 1 (2) pH 13 to pH 14 (4) pH 4 to pH 3 25 In a redox reaction, how does the total number of electrons lost by the oxidized substance compare to the total number of electrons gained by the reduced substance? (1) The number lost is always greater than the number gained. (2) The number lost is always equal to the number gained. (3) The number lost is sometimes equal to the number gained. (4) The number lost is sometimes less than the number gained. 31 Which radioisotope undergoes beta decay and has a half-life of less than 1 minute? (1) Fr-220 (3) N-16 (2) K-42 (4) P-32 32 Which set of symbols represents atoms with valence electrons in the same electron shell? (1) Ba, Br, Bi (3) O, S, Te (2) Sr, Sn, I (4) Mn, Hg, Cu 26 Which reaction is an example of an oxidationreduction reaction? (1) AgNO3 + KI → AgI + KNO3 (2) Cu + 2 AgNO3 → Cu(NO3)2 + 2 Ag (3) 2 KOH + H2SO4 → K2SO4 + 2 H2O (4) Ba(OH)2 + 2 HCl → BaCl2 + 2 H2O Note that question 33 has only three choices. 33 When compared with the energy of an electron in the first shell of a carbon atom, the energy of an electron in the second shell of a carbon atom is (1) less (2) greater (3) the same 27 Which compound is an Arrhenius base? (3) LiOH (1) CH3OH (2) CO2 (4) NO2 P.S./Chem.–Aug. ’04 [4] Part B–1 Answer all questions in this part. Directions (34–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 34 What is the total number of electrons found in an atom of sulfur? (1) 6 (3) 16 (2) 8 (4) 32 40 At STP, which of these substances is most soluble in H2O? (3) HCl (1) CCl4 (2) CO2 (4) N2 35 Which electron configuration represents the electrons of an atom in an excited state? (1) 2–8–1 (3) 2–8–17–6 (2) 2–8–6 (4) 2–8–18–5 41 Based on intermolecular forces, which of these substances would have the highest boiling point? (1) He (3) CH4 (2) O2 (4) NH3 36 The nucleus of an atom of cobalt-58 contains (1) 27 protons and 31 neutrons (2) 27 protons and 32 neutrons (3) 59 protons and 60 neutrons (4) 60 protons and 60 neutrons 42 How much heat energy must be absorbed to completely melt 35.0 grams of H2O(s) at 0°C? (1) 9.54 J (3) 11 700 J (2) 146 J (4) 79 100 J 43 The graph below represents the uniform heating of a substance, starting below its melting point, when the substance is solid. 38 Which substance is correctly paired with its type of bonding? (1) NaBr—nonpolar covalent (2) HCl—nonpolar covalent (3) NH3—polar covalent (4) Br2—polar covalent D B E C A Time Which line segments represent an increase in average kinetic energy? 39 A gas occupies a volume of 444 mL at 273 K and 79.0 kPa. What is the final kelvin temperature when the volume of the gas is changed to 1880 mL and the pressure is changed to 38.7 kPa? (1) 31.5 K (3) 566 K (2) 292 K (4) 2360 K P.S./Chem.–Aug. ’04 F Temperature 37 Which pair of formulas correctly represents a molecular formula and its corresponding empirical formula? (1) C2H2 and CH (3) C4H6 and CH (2) C3H4 and CH2 (4) C5H8 and C2H2 (1) AB and BC (2) AB and CD [5] (3) BC and DE (4) DE and EF [OVER] 44 Given the three organic structural formulas shown below: H H O H C C C H H H H H O C C H OH H H OH H C C C H H H H Which organic-compound classes are represented by these structural formulas, as shown from left to right? (1) ester, organic acid, ketone (3) ketone, aldehyde, alcohol (2) ester, aldehyde, organic acid (4) ketone, organic acid, alcohol 48 Which statement correctly describes a solution with a pH of 9? 45 Given the reaction at equilibrium: 2 NO(g) N2(g) + O2(g) + energy (1) It has a higher concentration of H3O+ than OH– and causes litmus to turn blue. (2) It has a higher concentration of OH– than H3O+ and causes litmus to turn blue. (3) It has a higher concentration of H3O+ than OH– and causes methyl orange to turn yellow. (4) It has a higher concentration of OH– than H3O+ and causes methyl orange to turn red. Which change will result in a decrease in the amount of NO(g) formed? (1) (2) (3) (4) decreasing the pressure decreasing the concentration of N2(g) increasing the concentration of O2(g) increasing the temperature 46 Given the equation: X + Cl2 → C2H5Cl + HCl 49 How many days are required for 200. grams of radon-222 to decay to 50.0 grams? (1) 1.91 days (3) 7.64 days (2) 3.82 days (4) 11.5 days Which molecule is represented by X? (1) C2H4 (2) C2H6 (3) C3H6 (4) C3H8 47 Which metal reacts spontaneously with a solution containing zinc ions? (1) magnesium (3) copper (2) nickel (4) silver P.S./Chem.–Aug. ’04 50 A student calculates the density of an unknown solid. The mass is 10.04 grams, and the volume is 8.21 cubic centimeters. How many significant figures should appear in the final answer? (1) 1 (3) 3 (2) 2 (4) 4 [6] Part B–2 Answer all questions in this part. Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 In the 19th century, Dmitri Mendeleev predicted the existence of a then unknown element X with a mass of 68. He also predicted that an oxide of X would have the formula X2O3. On the modern Periodic Table, what is the group number and period number of element X? [1] 52 Given the equation: 2 H2(g) + O2(g) → 2 H2O(g) If 8.0 moles of O2 are completely consumed, what is the total number of moles of H2O produced? [1] 53 In the space provided in your answer booklet, show a correct numerical setup for determining how many liters of a 1.2 M solution can be prepared with 0.50 mole of C6H12O6. [1] Base your answers to questions 54 through 57 on the particle diagrams below. Samples A, B, and C contain molecules at STP. A B C 54 Explain why the average kinetic energy of sample B is equal to the average kinetic energy of sample C. [1] 55 Explain, in terms of the composition, why sample A represents a pure substance. [1] 56 Explain why sample C could represent a mixture of fluorine and hydrogen chloride. [1] 57 Contrast sample A and sample B, in terms of compounds and mixtures. Include both sample A and sample B in your answer. [1] P.S./Chem.–Aug. ’04 [7] [OVER] Base your answers to questions 58 through 60 on the electronegativity values and atomic numbers of fluorine, chlorine, bromine, and iodine that are listed on Reference Table S. 58 On the grid provided in your answer booklet, mark an appropriate scale on the axis labeled “Electronegativity.” An appropriate scale is one that allows a trend to be seen. [1] 59 On the same grid, plot the electronegativity and atomic number data from Reference Table S. Circle and connect the points. [1] Example: 60 Explain, in terms of electronegativity, why the H–F bond is expected to be more polar than the H–I bond. [1] 61 What is the gram-formula mass of (NH4)2CO3? Use atomic masses rounded to the nearest whole number. [1] 62 In the space provided in your answer booklet, show a correct numerical setup for calculating the number of moles of CO2 (gram-formula mass = 44 g/mol) present in 11 grams of CO2. [1] Base your answers to questions 63 and 64 on the information below. Given the equilibrium equation at 298 K: KNO3(s) + 34.89 kJ H2O – K+(aq) + NO3 (aq) 63 Describe, in terms of LeChatelier’s principle, why an increase in temperature increases the solubility of KNO3. [1] 64 The equation indicates that KNO3 has formed a saturated solution. Explain, in terms of equilibrium, why the solution is saturated. [1] 65 In the space provided in your answer booklet, draw the structural formula for butanoic acid. [1] P.S./Chem.–Aug. ’04 [8] Part C Answer all questions in this part. Directions (66–85): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 66 through 69 on the information below, which describes the smelting of iron ore, and on your knowledge of chemistry. In the smelting of iron ore, Fe2O3 is reduced in a blast furnace at high temperature by a reaction with carbon monoxide. Crushed limestone, CaCO3, is also added to the mixture to remove impurities in the ore. The carbon monoxide is formed by the oxidation of carbon (coke), as shown in the reaction below: 2 C + O2 → 2 CO + energy Liquid iron flows from the bottom of the blast furnace and is processed into different alloys of iron. 66 Balance the equation for the reaction of Fe2O3 and CO in your answer booklet, using the smallest whole-number coefficients. [1] 67 Using the set of axes provided in your answer booklet, sketch a potential energy diagram for the reaction of carbon and oxygen that produces carbon monoxide. [1] 68 What is the oxidation number of carbon in CaCO3? [1] 69 Convert the melting point of iron metal to degrees Celsius. [1] Base your answers to questions 70 through 72 on the information below. Potassium ions are essential to human health. The movement of dissolved potassium ions, K+(aq), in and out of a nerve cell allows that cell to transmit an electrical impulse. 70 What is the total number of electrons in a potassium ion? [1] 71 Explain, in terms of atomic structure, why a potassium ion is smaller than a potassium atom. [1] 72 What property of potassium ions allows them to transmit an electrical impulse? P.S./Chem.–Aug. ’04 [9] [1] [OVER] Base your answers to questions 73 through 75 on the information below. Ethene (common name ethylene) is a commercially important organic compound. Millions of tons of ethene are produced by the chemical industry each year. Ethene is used in the manufacture of synthetic fibers for carpeting and clothing, and it is widely used in making polyethylene. Low-density polyethylene can be stretched into a clear, thin film that is used for wrapping food products and consumer goods. High-density polyethylene is molded into bottles for milk and other liquids. Ethene can also be oxidized to produce ethylene glycol, which is used in antifreeze for automobiles. The structural formula for ethylene glycol is: H H H C C H OH OH At standard atmospheric pressure, the boiling point of ethylene glycol is 198°C, compared to ethene that boils at –104°C. 73 Identify the type of organic reaction by which ethene (ethylene) is made into polyethylene. [1] 74 According to the information in the reading passage, state two consumer products manufactured from ethene. [1] 75 Explain, in terms of bonding, why ethene is an unsaturated hydrocarbon. [1] Base your answers to questions 76 through 78 on the diagram below, which represents a voltaic cell at 298 K and 1 atm. Voltmeter Wire V Switch S Salt bridge Pb electrode Zn electrode Half-cell 1 Half-cell 2 Pb2+(aq) Pb2+(aq) + Zn Zn2+(aq) Pb + Zn2+(aq) 76 In which half-cell will oxidation occur when switch S is closed? [1] 77 Write the balanced half-reaction equation that will occur in half-cell 1 when switch S is closed. [1] 78 Describe the direction of electron flow between the electrodes when switch S is closed. [1] P.S./Chem.–Aug. ’04 [10] Base your answers to questions 79 through 81 on the information and data table below. Indigestion may be caused by excess stomach acid (hydrochloric acid). Some products used to treat indigestion contain magnesium hydroxide. The magnesium hydroxide neutralizes some of the stomach acid. The amount of acid that can be neutralized by three different brands of antacids is shown in the data table below. Antacid Brand Mass of Antacid Tablet (g) Volume of HCl(aq) Neutralized (mL) X 2.00 25.20 Y 1.20 18.65 Z 1.75 22.50 79 Based on Reference Table F, describe the solubility of magnesium hydroxide in water. [1] 80 In the space provided in your answer booklet, show a correct numerical setup for calculating the milliliters of HCl(aq) neutralized per gram of antacid tablet for each brand of antacid. [1] 81 Which antacid brand neutralizes the most acid per gram of antacid tablet? P.S./Chem.–Aug. ’04 [11] [1] [OVER] Base your answers to questions 82 through 85 on the reading passage below and on your knowledge of chemistry. A Glow in the Dark, and Scientific Peril The [Marie and Pierre] Curies set out to study radioactivity in 1898. Their first accomplishment was to show that radioactivity was a property of atoms themselves. Scientifically, that was the most important of their findings, because it helped other researchers refine their understanding of atomic structure. More famous was their discovery of polonium and radium. Radium was the most radioactive substance the Curies had encountered. Its radioactivity is due to the large size of the atom, which makes the nucleus unstable and prone to decay, usually to radon and then lead, by emitting particles and energy as it seeks a more stable configuration. Marie Curie struggled to purify radium for medical uses, including early radiation treatment for tumors. But radium’s bluish glow caught people’s fancy, and companies in the United States began mining it and selling it as a novelty: for glow-in-the-dark light pulls, for instance, and bogus cure-all patent medicines that actually killed people. What makes radium so dangerous is that it forms chemical bonds in the same way as calcium, and the body can mistake it for calcium and absorb it into the bones. Then, it can bombard cells with radiation at close range, which may cause bone tumors or bone-marrow damage that can give rise to anemia or leukemia. — Denise Grady, The New York Times, October 6, 1998 82 State one risk associated with the use of radium. [1] 83 Using Reference Table N, complete the equation provided in your answer booklet for 226 the nuclear decay of 88Ra. Include both atomic number and mass number for each particle. [1] 84 Using information from the Periodic Table, explain why radium forms chemical bonds in the same way as calcium does. [1] 85 If a scientist purifies 1.0 gram of radium-226, how many years must pass before only 0.50 gram of the original radium-226 sample remains unchanged? [1] P.S./Chem.–Aug. ’04 [12] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Tuesday, August 17, 2004 — 12:30 to 3:30 p.m., only ANSWER SHEET ■ Male ■ Female Grade Student .............................................. Sex: ........... Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 12 . . . . . . . . . . . . 23 . . . . . . . . . . . 34 . . . . . . . . . . . . 43 . . . . . . . . . . . . 2 ............ 13 . . . . . . . . . . . . 24 . . . . . . . . . . . 35 . . . . . . . . . . . . 44 . . . . . . . . . . . . 3 ............ 14 . . . . . . . . . . . . 25 . . . . . . . . . . . 36 . . . . . . . . . . . . 45 . . . . . . . . . . . . 4 ............ 15 . . . . . . . . . . . . 26 . . . . . . . . . . . 37 . . . . . . . . . . . . 46 . . . . . . . . . . . . 5 ............ 16 . . . . . . . . . . . . 27 . . . . . . . . . . . 38 . . . . . . . . . . . . 47 . . . . . . . . . . . . 6 ............ 17 . . . . . . . . . . . . 28 . . . . . . . . . . . 39 . . . . . . . . . . . . 48 . . . . . . . . . . . . 7 ............ 18 . . . . . . . . . . . . 29 . . . . . . . . . . . 40 . . . . . . . . . . . . 49 . . . . . . . . . . . . 8 ............ 19 . . . . . . . . . . . . 30 . . . . . . . . . . . 41 . . . . . . . . . . . . 50 . . . . . . . . . . . . 9 ............ 20 . . . . . . . . . . . . 31 . . . . . . . . . . . 42 . . . . . . . . . . . . 10 . . . . . . . . . . . . 21 . . . . . . . . . . . . 32 . . . . . . . . . . . 11 . . . . . . . . . . . . 22 . . . . . . . . . . . . 33 . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Tuesday, August 17, 2004 — 12:30 to 3:30 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION A 33 B–1 17 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. For Raters Only Part B–2 51 Group 52 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . 51 and Period 52 mol 53 53 [1] For Raters Only 54 54 55 55 56 56 57 57 [2] For Raters Only Electronegativity 58 and 59 58 59 10 20 30 40 50 60 Atomic Number 60 60 61 g/mol 61 62 62 [3] [OVER] For Raters Only 63 63 64 64 65 65 Total Score for Part B–2 [4] For Raters Only Part C 67 Fe2O3 + CO → Fe + CO2 66 Potential Energy 66 67 Reaction Coordinate 68 68 69 70 69 °C 70 electrons 71 71 72 72 73 73 74 74 and 75 75 [5] [OVER] For Raters Only 76 76 77 77 78 78 79 79 X 80 Y Z 80 81 81 82 82 83 226 Ra 88 → + 83 84 84 85 85 y [6] Total Score for Part C PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 27, 2005 — 9:15 a.m. to 12:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 Germanium is classified as a (1) metal (3) nonmetal (2) metalloid (4) noble gas 1 As an electron in an atom moves from the ground state to the excited state, the electron (1) gains energy as it moves to a higher energy level (2) gains energy as it moves to a lower energy level (3) loses energy as it moves to a higher energy level (4) loses energy as it moves to a lower energy level 7 Which statement correctly describes diamond and graphite, which are different forms of solid carbon? (1) They differ in their molecular structure, only. (2) They differ in their properties, only. (3) They differ in their molecular structure and properties. (4) They do not differ in their molecular structure or properties. 2 Which subatomic particle will be attracted by a positively charged object? (1) proton (3) electron (2) neutron (4) positron 3 Which conclusion is based on the “gold experiment” and the resulting model of atom? (1) An atom is mainly empty space, and nucleus has a positive charge. (2) An atom is mainly empty space, and nucleus has a negative charge. (3) An atom has hardly any empty space, the nucleus has a positive charge. (4) An atom has hardly any empty space, the nucleus has a negative charge. foil the 8 What is the chemical formula for copper(II) hydroxide? (1) CuOH (3) Cu2(OH) (4) Cu(OH)2 (2) CuOH2 the the 9 What is the percent composition by mass of aluminum in Al2(SO4)3 (gram-formula mass = 342 grams/mole)? (1) 7.89% (3) 20.8% (2) 15.8% (4) 36.0% and and 4 Which two particles have approximately the same mass? (1) proton and neutron (2) proton and electron (3) neutron and electron (4) neutron and positron 10 Which statement describes a chemical property that can be used to distinguish between compound A and compound B? (1) A is a blue solid, and B is a white solid. (2) A has a high melting point, and B has a low melting point. (3) A dissolves in water, and B does not dissolve in water. (4) A does not burn in air, and B does burn in air. 5 Which element has chemical properties that are most similar to the chemical properties of sodium? (1) Mg (3) Se (2) K (4) Cl P.S./Chem.–Jan. ’05 [2] 18 Which transfer of energy occurs when ice cubes are placed in water that has a temperature of 45°C? (1) Chemical energy is transferred from the ice to the water. (2) Chemical energy is transferred from the water to the ice. (3) Thermal energy is transferred from the ice to the water. (4) Thermal energy is transferred from the water to the ice. 11 Which compound contains both ionic and covalent bonds? (3) MgF2 (1) CaCO3 (2) PCl3 (4) CH2O 12 Which formula represents a nonpolar molecule? (1) HCl (3) NH3 (2) H2O (4) CF4 13 When a lithium atom forms an Li+ ion, the lithium atom (1) gains a proton (2) gains an electron (3) loses a proton (4) loses an electron 19 At STP, 4 liters of O2 contains the same total number of molecules as (3) 8 L of He (1) 1 L of NH3 (2) 2 L of Cl2 (4) 4 L of CO2 14 Which Lewis electron-dot diagram represents a boron atom in the ground state? (1) B (3) B (2) B (4) B 20 What is the total number of electron pairs that are shared between the two carbon atoms in a molecule of ethyne? (1) 1 (3) 3 (2) 2 (4) 4 21 Which pair of compounds are isomers? (1) NO2 and N2O4 (2) P2O5 and P4O10 (3) HCOOH and CH3COOH (4) CH3OCH3 and C2H5OH 15 A sample is prepared by completely dissolving 10.0 grams of NaCl in 1.0 liter of H2O. Which classification best describes this sample? (1) homogeneous compound (2) homogeneous mixture (3) heterogeneous compound (4) heterogeneous mixture 22 Which organic compound is unsaturated? (1) 2-methylbutane (3) 2-hexanol (2) 2-chloropropane (4) 2-pentene 16 Which form of energy is converted to thermal energy when propane burns in air? (1) electromagnetic (3) electrical (2) nuclear (4) chemical 23 Which change in oxidation number indicates oxidation? (1) –1 to +2 (3) +2 to –3 (2) –1 to –2 (4) +3 to +2 17 Which physical changes are endothermic? (1) melting and freezing (2) melting and evaporating (3) condensation and sublimation (4) condensation and deposition P.S./Chem.–Jan. ’05 [3] [OVER] 28 Which reaction is an example of natural transmutation? 24 Given the redox reaction: Cr3+ + Al → Cr + Al3+ As the reaction takes place, there is a transfer of (1) (2) (3) (4) electrons from Al to Cr 3+ electrons from Cr3+ to Al protons from Al to Cr 3+ protons from Cr 3+ to Al 26 According to Reference Table M, what is the color of the indicator methyl orange in a solution that has a pH of 2? (1) blue (3) orange (2) yellow (4) red (2) 27 13Al (3) 238U 92 (4) 239Pu 94 4 → 235 92U + 2He 1 + 24He → 30 15P + 0n 0 + 01n → 239 94Pu + 2 –1e 90 1 + 10n → 147 56Ba + 38Sr + 30n 30 Which change takes place in a nuclear fusion reaction? (1) Matter is converted to energy. (2) Energy is converted to matter. (3) Ionic bonds are converted to covalent bonds. (4) Covalent bonds are converted to ionic bonds. 27 Given the reaction: NH3 + HCl → NH4Cl In this reaction, ammonia molecules (NH3) act as a base because they accept hydrogen ions (H+) accept hydroxide ions (OH–) donate hydrogen ions (H+) donate hydroxide ions (OH–) P.S./Chem.–Jan. ’05 239 Pu 94 29 Which statement best describes gamma radiation? (1) It has a mass of 1 and a charge of 1. (2) It has a mass of 0 and a charge of –1. (3) It has a mass of 0 and a charge of 0. (4) It has a mass of 4 and a charge of +2. 25 The compound HNO3 can be described as an (1) Arrhenius acid and an electrolyte (2) Arrhenius acid and a nonelectrolyte (3) Arrhenius base and an electrolyte (4) Arrhenius base and a nonelectrolyte (1) (2) (3) (4) (1) [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 36 How many electrons are in an Fe2+ ion? (1) 24 (3) 28 (2) 26 (4) 56 31 What is the total number of neutrons in the nucleus of a neutral atom that has 19 electrons and a mass number of 39? (1) 19 (3) 39 (2) 20 (4) 58 37 A substance that does not conduct electricity as a solid but does conduct electricity when melted is most likely classified as (1) an ionic compound (2) a molecular compound (3) a metal (4) a nonmetal 32 An unknown element X can form a compound with the formula XBr3. In which group on the Periodic Table would element X be found? (1) 1 (3) 13 (2) 2 (4) 14 33 As the elements in Group 17 on the Periodic Table are considered from top to bottom, what happens to the atomic radius and the metallic character of each successive element? (1) The atomic radius and the metallic character both increase. (2) The atomic radius increases and the metallic character decreases. (3) The atomic radius decreases and the metallic character increases. (4) The atomic radius and the metallic character both decrease. 38 According to Reference Table H, what is the boiling point of ethanoic acid at 80 kPa? (1) 28°C (3) 111°C (2) 100°C (4) 125°C 39 Which particle diagram represents one pure substance, only? 34 Which pair of compounds has the same empirical formula? (1) C2H2 and C6H6 (2) C2H6 and C3H8 (3) CH3OH and C2H5OH (4) CH3CHO and CH3COOH 35 Which equation shows a conservation of mass? (1) Na + Cl2 → NaCl (2) Al + Br2 → AlBr3 (3) H2O → H2 + O2 (4) PCl5 → PCl3 + Cl2 P.S./Chem.–Jan. ’05 [5] (1) (3) (2) (4) [OVER] 45 Which half-reaction can occur at the anode in a voltaic cell? (1) Ni2+ + 2e– → Ni (3) Zn → Zn2+ + 2e– (2) Sn + 2e– → Sn2+ (4) Fe3+ → Fe2+ + e– 40 A sample of helium gas has a volume of 900. milliliters and a pressure of 2.50 atm at 298 K. What is the new pressure when the temperature is changed to 336 K and the volume is decreased to 450. milliliters? (1) 0.177 atm (3) 5.64 atm (2) 4.43 atm (4) 14.1 atm 46 Given the reaction: Ba(OH)2(aq) + H2SO4(aq) → BaSO4(s) + 2 H2O() + energy 41 Given the particle diagram: As the barium hydroxide solution is added to the solution of sulfuric acid, the electrical conductivity of the acid solution decreases because the Key atom (1) (2) (3) (4) At 101.3 kPa and 298 K, which element could this diagram represent? (1) Rn (2) Xe (3) Ag (4) Kr 47 Which chemical equation represents the reaction of an Arrhenius acid and an Arrhenius base? (1) HC2H3O2(aq) + NaOH(aq) → NaC2H3O2(aq) + H2O() (2) C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O() (3) Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g) (4) BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2 NaCl(aq) 42 For most atoms with an atomic number less than 20, nuclear stability occurs when the ratio of neutrons to protons is 1:1. Which of the following atoms would be most likely to have an unstable nucleus? (1) 42He (3) 167N (2) 12 C 6 (4) 24Mg 12 48 Based on Reference Table F, which of these saturated solutions has the lowest concentration of dissolved ions? (1) NaCl(aq) (3) NiCl2(aq) (2) MgCl2(aq) (4) AgCl(aq) 43 Which of these changes produces the greatest increase in entropy? (1) CaCO3(s) → CaO(s) + CO2(g) (2) 2 Mg(s) + O2(g) → 2 MgO(s) (3) H2O(g) → H2O() (4) CO2(g) → CO2(s) 49 Based on Reference Table N, what fraction of a radioactive 90Sr sample would remain unchanged after 56.2 years? 44 Given the structural formula: H H H C C H N H (1) O C OH (2) P.S./Chem.–Jan. ’05 1 2 1 4 (3) (4) 1 8 1 16 50 Given the nuclear equation: 19 Ne → X + 19F 10 9 H Which particle is represented by X? This structural formula represents a molecule of (1) an aldehyde (2) an ester volume of the reaction mixture increases temperature of the reaction mixture decreases concentration of ions increases concentration of ions decreases (1) alpha (2) beta (3) a ketone (4) an amino acid [6] (3) neutron (4) positron Part B–2 Answer all questions in this part. Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 through 53 on your knowledge of chemical bonding and on the Lewis electron-dot diagrams of H2S, CO2, and F2 below. H S H O C O F F 51 Which atom, when bonded as shown, has the same electron configuration as an atom of argon? [1] 52 Explain, in terms of structure and/or distribution of charge, why CO2 is a nonpolar molecule. [1] – bond in CO is more polar than the 53 Explain, in terms of electronegativity, why a C–O 2 F–F bond in F2. [1] Temperature (K) Base your answers to questions 54 and 55 on the heating curve below, which represents a substance starting as a solid below its melting point and being heated at a constant rate over a period of time. F D E B C A Time (min) 54 What is happening to the average kinetic energy of the particles during segment BC ? [1] 55 How does this heating curve illustrate that the heat of vaporization is greater than the heat of fusion? [1] P.S./Chem.–Jan. ’05 [7] [OVER] Potential Energy Base your answers to questions 56 through 58 on the potential energy diagram and the equation below. B (2) (3) A (4) (1) Reaction Coordinate 2 C(s) + H 2(g) + 227.4 kJ → C 2H 2(g) 56 The letter B represents which chemical formula or formulas in the equation? 57 If 682.2 kilojoules are absorbed, how many moles of C2H2(g) are produced? 58 Describe how the potential energy diagram will change if a catalyst is added. [1] [1] [1] Base your answers to questions 59 and 60 on the condensed structural formula below. CH3CH2CHCH2 59 In the space provided in your answer booklet, draw the structural formula for this compound. [1] 60 The formula below represents a product formed when HCl reacts with CH3CH2CHCH2. H H H H H C C C C H Cl H H What is an IUPAC name for this product? P.S./Chem.–Jan. ’05 [8] [1] H 61 Given the equation: catalyst butanoic acid + 1-pentanol water + X To which class of organic compounds does product X belong? [1] 62 Identify the homologous series of hydrocarbons to which CH3CHCH2 belongs. [1] Base your answers to questions 63 through 65 on the information below. In a titration experiment, a student uses a 1.4 M HBr(aq) solution and the indicator phenolphthalein to determine the concentration of a KOH(aq) solution. The data for trial 1 is recorded in the table below. Trial 1 Buret Readings HBr(aq) KOH(aq) Initial volume (mL) 7.50 11.00 Final volume (mL) 22.90 33.10 Volume used (mL) 15.40 22.10 63 In the space provided in your answer booklet, show a correct numerical setup for calculating the molarity of the KOH(aq) solution for trial 1. [1] 64 Why is it better to use several trials of a titration rather than one trial to determine the molarity of a solution of an unknown concentration? [1] 65 In a second trial of this experiment, the molarity of KOH(aq) was determined to be 0.95 M. The actual molarity was 0.83 M. What is the percent error in the second trial? [1] P.S./Chem.–Jan. ’05 [9] [OVER] Part C Answer all questions in this part. Directions (66–84): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 66 and 67 on the information below. Naturally occurring elemental carbon is a mixture of isotopes. The percent composition of the two most abundant isotopes is listed below. • 98.93% of the carbon atoms have a mass of 12.00 atomic mass units. • 1.07% of the carbon atoms have a mass of 13.00 atomic mass units. 66 In the space provided in your answer booklet, show a correct numerical setup for calculating the average atomic mass of carbon. [1] 67 Describe, in terms of subatomic particles found in the nucleus, one difference between the nuclei of carbon-12 atoms and the nuclei of carbon-13 atoms. The response must include both isotopes. [1] Base your answers to questions 68 and 69 on the information below. A scientist in a chemistry laboratory determined the molecular formulas for two compounds containing nitrogen and oxygen to be NO2 and N2O5. 68 Write an IUPAC name for the compound N2O5. [1] 69 In the space provided in your answer booklet, show a correct numerical setup for calculating the percent composition by mass of oxygen in NO2. [1] P.S./Chem.–Jan. ’05 [10] Base your answers to questions 70 through 72 on the information below. In a laboratory experiment, 10.00 grams of an unknown solid is added to 100.0 milliliters of water and the temperature of the resulting solution is measured over several minutes, as recorded in the table below. Data Table Time (minutes) Temperature (°C) 0 24.0 0.5 28.5 1.0 31.0 1.5 34.5 2.0 41.0 2.5 45.5 3.0 46.5 70 On the grid provided in your answer booklet, mark an appropriate scale on the axis labeled “Temperature (°C).” An appropriate scale is one that allows a trend to be seen. [1] 71 Plot the data from the data table. Circle and connect the points. [1] Example: 72 Given the statement: The unknown solid is either sodium hydroxide or lithium bromide, and both of these compounds dissolve in water exothermically. a Explain how the experimental data support the statement. [1] b State specific information from Reference Table I to support the statement. P.S./Chem.–Jan. ’05 [11] [1] [OVER] Base your answers to questions 73 through 76 on the information below. Figure 1 50.0 g Cu(s) at 100.0°C In a laboratory investigation, a 50.0-gram sample of copper is at 100.0°C in a boiling water bath. Figure 2 100.0 g H2O( ) at 23.2°C A Styrofoam cup with a lid is used as a calorimeter. The cup contains 100.0 grams of distilled water at 23.2°C. Calorimeter Figure 3 The hot copper is poured into the cup of water, and the cup is quickly covered with the lid. Calorimeter Figure 4 A thermometer is inserted through the lid. The copper and water are gently stirred in the cup. The temperature is checked periodically. The highest temperature noted is 26.3°C. Calorimeter P.S./Chem.–Jan. ’05 [12] 73 In terms of energy flow, explain why the temperature of the water in the calorimeter increases. [1] 74 Using the information given, complete the data table provided in your answer booklet. [1] 75 In the space provided in your answer booklet, show a correct numerical setup for calculating the number of joules of heat gained by the water. [1] 76 In this investigation, the change in heat of the copper is greater than the change in heat of the water. What error could account for this apparent violation of the Law of Conservation of Energy? Do not use human error as part of the answer. [1] Base your answers to questions 77 through 79 on the information below. Two alcohols that are used in our everyday lives are rubbing alcohol and ethylene glycol. Rubbing alcohol is used as an antiseptic. Ethylene glycol is the main ingredient in antifreeze, which is used in automobile cooling systems. 77 Explain, in terms of molecular polarity, why rubbing alcohol, 2-propanol, is soluble in water. [1] 78 What is the gram-formula mass of ethylene glycol, C2H4(OH)2? [1] 79 In the space provided in your answer booklet, show a correct numerical setup for calculating the total number of moles of ethylene glycol needed to prepare 2.50 liters of a 10.0 M solution. [1] Base your answers to questions 80 and 81 on the information below. The outer structure of the Statue of Liberty is made of copper metal. The framework is made of iron. Over time, a thin green layer (patina) forms on the copper surface. 80 When copper oxidized to form this patina layer, the copper atoms became copper(II) ions (Cu2+). Write a balanced half-reaction for this oxidation of copper. [1] 81 Where the iron framework came in contact with the copper surface, a reaction occurred in which iron was oxidized. Using information from Reference Table J, explain why the iron was oxidized. [1] P.S./Chem.–Jan. ’05 [13] [OVER] Base your answers to questions 82 through 84 on the information below, the Reference Tables for Physical Setting/Chemistry, and your knowledge of chemistry. Radioactivity and radioactive isotopes have the potential for both benefiting and harming living organisms. One use of radioactive isotopes is in radiation therapy as a treatment for cancer. Cesium-137 is sometimes used in radiation therapy. A sample of cesium-137 was left in an abandoned clinic in Brazil in 1987. Cesium-137 gives off a blue glow because of its radioactivity. The people who discovered the sample were attracted by the blue glow and had no idea of any danger. Hundreds of people were treated for overexposure to radiation, and four people died. 82 Using Reference Table N, complete the equation provided in your answer booklet for the radioactive decay of 137 55Cs. Include both atomic number and mass number for each particle. [1] 83 If 12.5 grams of the original sample of cesium-137 remained after 90.69 years, what was the mass of the original sample? [1] 84 Suppose a 40-gram sample of iodine-131 and a 40-gram sample of cesium-137 were both abandoned in the clinic in 1987. Explain why the sample of iodine-131 would not pose as great a radiation risk to people today as the sample of cesium-137 would. [1] P.S./Chem.–Jan. ’05 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Thursday, January 27, 2005 — 9:15 a.m. to 12:15 p.m., only ANSWER SHEET ■ Male ■ Female Grade . . . . . . . . . . . . Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part A Score Part B–1 Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Thursday, January 27, 2005 — 9:15 a.m. to 12:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION A 30 B–1 20 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only Part B–2 51 51 52 52 53 53 [1] For Raters Only 54 54 55 55 56 57 56 mol 57 58 58 59 59 60 60 61 61 62 62 [2] For Raters Only 63 63 64 64 65 % 65 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 66 66 67 67 68 68 69 69 [4] For Raters Only Change in Temperature During the Dissolving of a Solid Temperature (°C) 70 and 71 70 71 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Time (min) 72 a 72a b b [5] [OVER] For Raters Only 73 73 74 Data Table Data (units are given) Quantity Measured Mass of copper g Temperature of hot copper °C Mass of H2O in calorimeter g Initial temperature of H2O in calorimeter °C Final temperature of H2O and copper °C 74 75 75 76 76 [6] For Raters Only 77 77 78 g/mol 78 79 79 80 80 81 81 82 83 137Cs 55 → + 82 g 83 84 84 Total Score for Part C [7] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 22, 2005 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–33): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 Which element is malleable and conducts electricity? (1) iron (3) sulfur (2) iodine (4) phosphorus 1 In the modern wave-mechanical model of the atom, the orbitals are regions of the most probable location of (1) protons (3) electrons (2) neutrons (4) positrons 8 At STP, solid carbon can exist as graphite or as diamond. These two forms of carbon have (1) the same properties and the same crystal structures (2) the same properties and different crystal structures (3) different properties and the same crystal structures (4) different properties and different crystal structures 2 Compared to a proton, an electron has (1) a greater quantity of charge and the same sign (2) a greater quantity of charge and the opposite sign (3) the same quantity of charge and the same sign (4) the same quantity of charge and the opposite sign 3 Which two notations represent atoms that are isotopes of the same element? (1) (2) 121 Sn 50 121 Sn 50 and 119 50 Sn (3) and 121 50 Sn (4) 9 What is the formula of titanium(II) oxide? (1) TiO (3) Ti2O (2) TiO2 (4) Ti2O3 19 O and 19 F 8 9 39 Cl and 39 K 17 19 4 The elements in Period 5 on the Periodic Table are arranged from left to right in order of (1) decreasing atomic mass (2) decreasing atomic number (3) increasing atomic mass (4) increasing atomic number 10 Which substance can be decomposed by a chemical change? (1) calcium (3) copper (2) potassium (4) ammonia 11 As a chlorine atom becomes a negative ion, the atom (1) gains an electron and its radius increases (2) gains an electron and its radius decreases (3) loses an electron and its radius increases (4) loses an electron and its radius decreases 5 Which list of elements contains a metal, a metalloid, and a nonmetal? (1) Zn, Ga, Ge (3) Cd, Sb, I (2) Si, Ge, Sn (4) F, Cl, Br 6 An example of a physical property of an element is the element’s ability to (1) react with an acid (2) react with oxygen (3) form a compound with chlorine (4) form an aqueous solution P.S./Chem.–June ’05 12 Based on Reference Table S, the atoms of which of these elements have the strongest attraction for electrons in a chemical bond? (1) N (3) P (2) Na (4) Pt [2] 19 Adding a catalyst to a chemical reaction results in (1) a decrease in activation energy and a decrease in the reaction rate (2) a decrease in activation energy and an increase in the reaction rate (3) an increase in activation energy and a decrease in the reaction rate (4) an increase in activation energy and an increase in the reaction rate 13 Which terms are used to identify pure substances? (1) an element and a mixture (2) an element and a compound (3) a solution and a mixture (4) a solution and a compound 14 The solubility of KClO3(s) in water increases as the (1) temperature of the solution increases (2) temperature of the solution decreases (3) pressure on the solution increases (4) pressure on the solution decreases 20 Systems in nature tend to undergo changes toward (1) lower energy and lower entropy (2) lower energy and higher entropy (3) higher energy and lower entropy (4) higher energy and higher entropy 15 Compared to a 0.1 M aqueous solution of NaCl, a 0.8 M aqueous solution of NaCl has a (1) higher boiling point and a higher freezing point (2) higher boiling point and a lower freezing point (3) lower boiling point and a higher freezing point (4) lower boiling point and a lower freezing point 21 Which element has atoms that can bond with each other to form long chains or rings? (1) carbon (3) oxygen (2) nitrogen (4) fluorine 22 Which formula represents an unsaturated hydrocarbon? (1) C2H6 (3) C5H8 (2) C3H8 (4) C6H14 16 The kinetic molecular theory assumes that the particles of an ideal gas (1) are in random, constant, straight-line motion (2) are arranged in a regular geometric pattern (3) have strong attractive forces between them (4) have collisions that result in the system losing energy 23 Given the structural formula: H C 17 In which process does a solid change directly into a vapor? (1) condensation (3) deposition (2) sublimation (4) solidification C H H C H H What is the IUPAC name of this compound? (1) propane (2) propene 18 Which statement must be true about a chemical system at equilibrium? (1) The forward and reverse reactions stop. (2) The concentration of reactants and products are equal. (3) The rate of the forward reaction is equal to the rate of the reverse reaction. (4) The number of moles of reactants is equal to the number of moles of product. P.S./Chem.–June ’05 H (3) propanone (4) propanal 24 What is the oxidation state of nitrogen in NaNO2? (1) +1 (3) +3 (2) +2 (4) +4 [3] [OVER] 30 Which equation represents a transmutation reaction? 25 The three isomers of pentane have different (1) formula masses (2) molecular formulas (3) empirical formulas (4) structural formulas (1) (2) 239 U → 239 U + 0 γ 92 92 0 14 C → 14 N + 0e 6 7 –1 (3) C3H8 + 5O2 → 3CO2 + 4H2O 26 Where does oxidation occur in an electrochemical cell? (1) at the cathode in both an electrolytic cell and a voltaic cell (2) at the cathode in an electrolytic cell and at the anode in a voltaic cell (3) at the anode in both an electrolytic cell and a voltaic cell (4) at the anode in an electrolytic cell and at the cathode in a voltaic cell (4) nC2H4 (–C2H4–)n 31 Which equation represents positron decay? (1) (2) (3) (4) 87 Rb → 0e + 87Sr 37 –1 38 227U → 223 Th + 4He 92 90 2 27 Al + 4He → 30P + 1n 13 2 15 0 11C → 0 e + 11B 6 +1 5 32 Which equation represents a fusion reaction? 27 Which formula represents an electrolyte? (1) CH3OCH3 (3) CH3COOH (2) CH3OH (4) C2H5CHO (1) H2O(g) → H2O() (2) C(s) + O2(g) → CO2(g) (3) 21H + 31H → 42He + 10n (4) 28 When an Arrhenius acid dissolves in water, the only positive ion in the solution is (3) Na+ (1) H+ + (2) Li (4) K+ 235U 92 91 1 + 10n → 142 56Ba + 36Kr + 30n Note that question 33 has only three choices. 33 An electron in an atom moves from the ground state to an excited state when the energy of the electron (1) decreases (2) increases (3) remains the same 29 What is the half-life and decay mode of Rn-222? (1) 1.91 days and alpha decay (2) 1.91 days and beta decay (3) 3.82 days and alpha decay (4) 3.82 days and beta decay P.S./Chem.–June ’05 catalyst [4] Part B–1 Answer all questions in this part. Directions (34–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 34 Which symbol represents a particle that has the same total number of electrons as S2–? (3) Se2– (1) O2– (2) Si (4) Ar 39 A sample of a substance containing only magnesium and chlorine was tested in the laboratory and was found to be composed of 74.5% chlorine by mass. If the total mass of the sample was 190.2 grams, what was the mass of the magnesium? (1) 24.3 g (3) 70.9 g (2) 48.5 g (4) 142 g 35 The data table below shows elements Xx, Yy, and Zz from the same group on the Periodic Table. Element Atomic Mass (atomic mass unit) Atomic Radius (pm) Xx 69.7 141 Yy 114.8 ? Zz 204.4 171 40 Which molecule contains a nonpolar covalent bond? O O Br Br (1) (3) CI C What is the most likely atomic radius of element Yy? (1) 103 pm (2) 127 pm C O CI C CI CI (3) 166 pm (4) 185 pm (2) (4) 41 According to Reference Table G, which substance forms an unsaturated solution when 80 grams of the substance is dissolved in 100 grams of H2O at 10°C? (1) KI (3) NaNO3 (2) KNO3 (4) NaCl 36 Which substance has a chemical formula with the same ratio of metal ions to nonmetal ions as in potassium sulfide? (1) sodium oxide (2) sodium chloride (3) magnesium oxide (4) magnesium chloride 42 What is the concentration of a solution, in parts per million, if 0.02 gram of Na3PO4 is dissolved in 1000 grams of water? (1) 20 ppm (3) 0.2 ppm (2) 2 ppm (4) 0.02 ppm 37 The molecular formula of glucose is C6H12O6. What is the empirical formula of glucose? (1) CHO (3) C6H12O6 (2) CH2O (4) C12H24O12 38 According to Reference Table F, which of these compounds is the least soluble in water? (1) K2CO3 (2) KC2H3O2 P.S./Chem.–June ’05 (3) Ca3(PO4)2 (4) Ca(NO3)2 [5] [OVER] 46 At STP, fluorine is a gas and iodine is a solid. This observation can be explained by the fact that fluorine has (1) weaker intermolecular forces of attraction than iodine (2) stronger intermolecular forces of attraction than iodine (3) lower average kinetic energy than iodine (4) higher average kinetic energy than iodine 43 Given the simple representations for atoms of two elements: = an atom of an element = an atom of a different element Which particle diagram represents molecules of only one compound in the gaseous phase? 47 Given the structural formula: H H H H H C C O C C H (1) H H (3) H H The compound represented by this formula can be classified as an (1) organic acid (2) ether (2) 48 Sulfuric acid, H2SO4(aq), can be used to neutralize barium hydroxide, Ba(OH)2(aq). What is the formula for the salt produced by this neutralization? (1) BaS (3) BaSO3 (2) BaSO2 (4) BaSO4 (4) 44 Given the balanced equation: KNO3(s) + 34.89 kJ H2O K+(aq) + NO3–(aq) Which statement best describes this process? (1) (2) (3) (4) 49 Given the balanced ionic equation: It is endothermic and entropy increases. It is endothermic and entropy decreases. It is exothermic and entropy increases. It is exothermic and entropy decreases. Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s) Which equation represents the oxidation halfreaction? (1) (2) (3) (4) 45 A 1.0-gram piece of zinc reacts with 5 milliliters of HCl(aq). Which of these conditions of concentration and temperature would produce the greatest rate of reaction? (1) 1.0 M HCl(aq) at 20.°C (2) 1.0 M HCl(aq) at 40.°C (3) 2.0 M HCl(aq) at 20.°C (4) 2.0 M HCl(aq) at 40.°C P.S./Chem.–June ’05 (3) ester (4) aldehyde Zn(s) + 2e– → Zn2+(aq) Zn(s) → Zn2+(aq) + 2e– Cu2+(aq) → Cu(s) + 2e– Cu2+(aq) + 2e– → Cu(s) 50 In which solution will thymol blue indicator appear blue? (1) 0.1 M CH3COOH (3) 0.1 M HCl (2) 0.1 M KOH (4) 0.1 M H2SO4 [6] Part B–2 Answer all questions in this part. Directions (51–64): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 and 52 on the diagram below, which represents an atom of magnesium-26 in the ground state. Mg-26 nucleus 2 8 2 51 What is the total number of valence electrons in an atom of Mg-26 in the ground state? [1] 52 On the diagram in your answer booklet, write an appropriate number of electrons in each shell to represent a Mg-26 atom in an excited state. Your answer may include additional shells. [1] 53 Explain, in terms of atomic structure, why germanium is chemically similar to silicon. [1] 54 Given the balanced equation: 4Al(s) + 3O2(g) → 2Al2O3(s) What is the total number of moles of O2(g) that must react completely with 8.0 moles of Al(s) in order to form Al2O3(s)? [1] Base your answers to questions 55 and 56 on the balanced equation below. 2Na(s) + Cl2(g) → 2NaCl(s) 55 In the box in your answer booklet, draw a Lewis electron-dot diagram for a molecule of chlorine, Cl2. [1] 56 Explain, in terms of electrons, why the bonding in NaCl is ionic. [1] P.S./Chem.–June ’05 [7] [OVER] Base your answers to questions 57 and 58 on the information below. Given the reaction at equilibrium: 2NO2(g) + 7H2(g) 2NH3(g) + 4H2O(g) + 1127 kJ 57 On the diagram in your answer booklet, complete the potential energy diagram for the forward reaction. Be sure your drawing shows the activation energy and the potential energy of the products. [2] 58 Explain, in terms of Le Chatelier’s principle, why the concentration of NH3(g) decreases when the temperature of the equilibrium system increases. [1] Base your answers to questions 59 and 60 on the information below. Given the reaction between 1-butene and chlorine gas: C4H8 + Cl2 → C4H8Cl2 59 Which type of chemical reaction is represented by this equation? [1] 60 In the space in your answer booklet, draw the structural formula of the product 1,2-dichlorobutane. [1] P.S./Chem.–June ’05 [8] Base your answers to questions 61 through 64 on the information below, which relates the numbers of neutrons and protons for specific nuclides of C, N, Ne, and S. Number of Neutrons Versus Number of Protons in Selected Nuclides 20 This line connects points where the neutron-to-proton ratio is 1:1 S Number of Neutrons 15 10 N Ne C 5 0 5 10 15 Number of Protons 20 61 Using the point plotted on the graph for neon, complete the table in your answer booklet. [1] 62 Explain, in terms of atomic particles, why S-32 is a stable nuclide. [1] 63 Using the point plotted on the graph for nitrogen, what is the neutron-to-proton ratio of this nuclide? [1] 64 Based on Reference Table N, complete the decay equation for N-16 in your answer booklet. [1] P.S./Chem.–June ’05 [9] [OVER] Part C Answer all questions in this part. Directions (65–83): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 65 In the early 1900s, experiments were conducted to determine the structure of the atom. One of these experiments involved bombarding gold foil with alpha particles. Most alpha particles passed directly through the foil. Some, however, were deflected at various angles. Based on this alpha particle experiment, state two conclusions that were made concerning the structure of an atom. [2] Base your answers to questions 66 through 70 on the information below. A substance is a solid at 15°C. A student heated a sample of the solid substance and recorded the temperature at one-minute intervals in the data table below. Time (min) 0 1 2 3 4 5 6 7 8 9 10 11 12 Temperature (°C) 15 32 46 53 53 53 53 53 53 53 53 60 65 66 On the grid in your answer booklet, mark an appropriate scale on the axis labeled “Temperature (°C).” An appropriate scale is one that allows a trend to be seen. [1] 67 Plot the data from the data table. Circle and connect the points. [1] Example: 68 Based on the data table, what is the melting point of this substance? [1] 69 What is the evidence that the average kinetic energy of the particles of this substance is increasing during the first three minutes? [1] 70 The heat of fusion for this substance is 122 joules per gram. How many joules of heat are needed to melt 7.50 grams of this substance at its melting point? [1] P.S./Chem.–June ’05 [10] Base your answers to questions 71 through 73 on the diagram of a voltaic cell and the balanced ionic equation below. Wire Wire V Voltmeter Salt bridge Mg(s) Mg2+(aq) Ni(s) Ni2+(aq) Mg(s) + Ni2+(aq) Mg2+(aq) + Ni(s) 71 What is the total number of moles of electrons needed to completely reduce 6.0 moles of Ni2+(aq) ions? [1] 72 Identify one metal from Reference Table J that is more easily oxidized than Mg(s). [1] 73 Explain the function of the salt bridge in the voltaic cell. [1] Base your answers to questions 74 through 76 on the passage below. Acid rain is a problem in industrialized countries around the world. Oxides of sulfur and nitrogen are formed when various fuels are burned. These oxides dissolve in atmospheric water droplets that fall to earth as acid rain or acid snow. While normal rain has a pH between 5.0 and 6.0 due to the presence of dissolved carbon dioxide, acid rain often has a pH of 4.0 or lower. This level of acidity can damage trees and plants, leach minerals from the soil, and cause the death of aquatic animals and plants. If the pH of the soil is too low, then quicklime, CaO, can be added to the soil to increase the pH. Quicklime produces calcium hydroxide when it dissolves in water. 74 Balance the neutralization equation in your answer booklet, using the smallest wholenumber coefficients. [1] 75 A sample of wet soil has a pH of 4.0. After the addition of quicklime, the H+ ion concentration of the soil is 1 100 of the original H+ ion concentration of the soil. What is the new pH of the soil sample? [1] 76 Samples of acid rain are brought to a laboratory for analysis. Several titrations are performed and it is determined that a 20.0-milliliter sample of acid rain is neutralized with 6.50 milliliters of 0.010 M NaOH. What is the molarity of the H+ ions in the acid rain? [1] P.S./Chem.–June ’05 [11] [OVER] Base your answers to questions 77 through 79 on the information and diagrams below. Cylinder A contains 22.0 grams of CO2(g) and cylinder B contains N2(g). The volumes, pressures, and temperatures of the two gases are indicated under each cylinder. Cylinder A Cylinder B CO2(g) N2(g) V = 12.3 L P = 1.0 atm T = 300. K V = 12.3 L P = 1.0 atm T = 300. K 77 What is the total number of moles of CO2(g) in cylinder A? [1] 78 Explain why the number of molecules of N2(g) in cylinder B is the same as the number of molecules of CO2(g) in cylinder A. [1] 79 The temperature of the CO2(g) is increased to 450. K and the volume of cylinder A remains constant. In the space in your answer booklet, show a correct numerical setup for calculating the new pressure of the CO2(g) in cylinder A. [1] P.S./Chem.–June ’05 [12] Base your answers to questions 80 through 83 on the information and diagram below and on your knowledge of chemistry. Crude oil is a mixture of many hydrocarbons that have different numbers of carbon atoms. The use of a fractionating tower allows the separation of this mixture based on the boiling points of the hydrocarbons. To begin the separation process, the crude oil is heated to about 400°C in a furnace, causing many of the hydrocarbons of the crude oil to vaporize. The vaporized mixture is pumped into a fractionating tower that is usually more than 30 meters tall. The temperature of the tower is highest at the bottom. As vaporized samples of hydrocarbons travel up the tower, they cool and condense. The liquid hydrocarbons are collected on trays and removed from the tower. The diagram below illustrates the fractional distillation of the crude oil and the temperature ranges in which the different hydrocarbons condense. Distillation of Crude Oil Less than 40°C Hydrocarbons with 1 to 4 carbon atoms 40°C – 200°C Hydrocarbons with 5 to 12 carbon atoms Decreasing temperature 200°C – 300°C Hydrocarbons with 12 to 16 carbon atoms 250°C – 350°C Hydrocarbons with 15 to 18 carbon atoms 300°C – 370°C Hydrocarbons with 16 to 20 carbon atoms Greater than 370°C Crude oil Furnace Fractionating tower Hydrocarbons with more than 20 carbon atoms 80 State the trend between the boiling point of the hydrocarbons contained in the crude oil and the number of carbon atoms in these molecules. [1] 81 Describe the relationship between the strength of the intermolecular forces and the number of carbon atoms in the different hydrocarbon molecules. [1] 82 Write an IUPAC name of one saturated hydrocarbon that leaves the fractionating tower at less than 40°C. [1] 83 How many hydrogen atoms are present in one molecule of octane? [1] P.S./Chem.–June ’05 [13] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, June 22, 2005 — 1:15 to 4:15 p.m., only ANSWER SHEET ■ Male ■ Female Grade Student .............................................. Sex: ........... Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 12 . . . . . . . . . . . . 23 . . . . . . . . . . . 34 . . . . . . . . . . . . 43 . . . . . . . . . . . . 2 ............ 13 . . . . . . . . . . . . 24 . . . . . . . . . . . 35 . . . . . . . . . . . . 44 . . . . . . . . . . . . 3 ............ 14 . . . . . . . . . . . . 25 . . . . . . . . . . . 36 . . . . . . . . . . . . 45 . . . . . . . . . . . . 4 ............ 15 . . . . . . . . . . . . 26 . . . . . . . . . . . 37 . . . . . . . . . . . . 46 . . . . . . . . . . . . 5 ............ 16 . . . . . . . . . . . . 27 . . . . . . . . . . . 38 . . . . . . . . . . . . 47 . . . . . . . . . . . . 6 ............ 17 . . . . . . . . . . . . 28 . . . . . . . . . . . 39 . . . . . . . . . . . . 48 . . . . . . . . . . . . 7 ............ 18 . . . . . . . . . . . . 29 . . . . . . . . . . . 40 . . . . . . . . . . . . 49 . . . . . . . . . . . . 8 ............ 19 . . . . . . . . . . . . 30 . . . . . . . . . . . 41 . . . . . . . . . . . . 50 . . . . . . . . . . . . 9 ............ 20 . . . . . . . . . . . . 31 . . . . . . . . . . . 42 . . . . . . . . . . . . 10 . . . . . . . . . . . . 21 . . . . . . . . . . . . 32 . . . . . . . . . . . 11 . . . . . . . . . . . . 22 . . . . . . . . . . . . 33 . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Wednesday, June 22, 2005 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION A 33 B–1 17 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. For Raters Only Part B–2 51 51 52 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . Mg-26 nucleus 2 8 2 52 53 53 [1] [OVER] For Raters Only 54 mol 54 55 55 56 56 Potential Energy 57 57 2NO2(g) + 7H2(g) Reaction Coordinate 58 58 [2] For Raters Only 59 59 60 60 61 Element Number of Protons Number of Neutrons Mass Number Nuclide C 6 6 12 C-12 N 7 9 16 N-16 Ne 10 S 16 16 32 S-32 61 62 62 63 64 63 16N 7 → + 64 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 65 Conclusion 1: 65 Conclusion 2: 66 and 67 Temperature (°C) Heating Curve 66 67 0 1 2 3 4 5 6 7 8 9 10 11 12 Time (min) 68 68 °C [4] For Raters Only 69 69 70 J 70 71 mol 71 72 72 73 73 74 HNO3 + Ca(OH)2 → Ca(NO3)2 + 75 76 H2O 74 75 M 76 [5] [OVER] For Raters Only 77 mol 77 78 78 79 79 80 80 81 81 82 82 83 83 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Tuesday, August 16, 2005 — 12:30 to 3:30 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 The elements located in the lower left corner of the Periodic Table are classified as (1) metals (3) metalloids (2) nonmetals (4) noble gases 1 Which subatomic particle has a negative charge? (1) proton (3) neutron (2) electron (4) positron 2 Which statement best describes the nucleus of an aluminum atom? (1) It has a charge of +13 and is surrounded by a total of 10 electrons. (2) It has a charge of +13 and is surrounded by a total of 13 electrons. (3) It has a charge of –13 and is surrounded by a total of 10 electrons. (4) It has a charge of –13 and is surrounded by a total of 13 electrons. 7 Which of these elements has the lowest melting point? (1) Li (3) K (2) Na (4) Rb 8 Which list consists of elements that have the most similar chemical properties? (1) Mg, Al, and Si (3) K, Al, and Ni (2) Mg, Ca, and Ba (4) K, Ca, and Ga 3 The atomic mass of an element is the weighted average of the (1) number of protons in the isotopes of that element (2) number of neutrons in the isotopes of that element (3) atomic numbers of the naturally occurring isotopes of that element (4) atomic masses of the naturally occurring isotopes of that element 9 The correct chemical formula for iron(II) sulfide is (1) FeS (3) FeSO4 (2) Fe2S3 (4) Fe2(SO4)3 10 Which list consists of types of chemical formulas? (1) atoms, ions, molecules (2) metals, nonmetals, metalloids (3) empirical, molecular, structural (4) synthesis, decomposition, neutralization 4 In which pair do the particles have approximately the same mass? (1) proton and electron (2) proton and neutron (3) neutron and electron (4) neutron and beta particle 11 Which type of bonding is found in all molecular substances? (1) covalent bonding (3) ionic bonding (2) hydrogen bonding (4) metallic bonding 12 An aqueous solution of sodium chloride is best classified as a (1) homogeneous compound (2) homogeneous mixture (3) heterogeneous compound (4) heterogeneous mixture 5 Two different samples decompose when heated. Only one of the samples is soluble in water. Based on this information, these two samples are (1) both the same element (2) two different elements (3) both the same compound (4) two different compounds P.S./Chem.–Aug. ’05 [2] 19 Which formula represents an unsaturated hydrocarbon? 13 What is the total number of electrons shared in a double covalent bond between two atoms? (1) 1 (3) 8 (2) 2 (4) 4 H 14 Which formula represents a nonpolar molecule? (3) CH4 (1) H2S (2) HCl (4) NH3 H C C H H H H H O C C H (3) H C C H H H (1) 15 What occurs when an atom loses an electron? (1) The atom’s radius decreases and the atom becomes a negative ion. (2) The atom’s radius decreases and the atom becomes a positive ion. (3) The atom’s radius increases and the atom becomes a negative ion. (4) The atom’s radius increases and the atom becomes a positive ion. H H H H C C H H (2) CI (4) 20 Given the formula: 16 Two samples of gold that have different temperatures are placed in contact with one another. Heat will flow spontaneously from a sample of gold at 60°C to a sample of gold that has a temperature of (1) 50°C (3) 70°C (2) 60°C (4) 80°C H H H C C H H H C C C H H H H What is the IUPAC name of this compound? (1) 2-pentene (2) 2-pentyne (3) 2-butene (4) 2-butyne 21 Given the reaction system in a closed container at equilibrium and at a temperature of 298 K: 17 Under which conditions of temperature and pressure would helium behave most like an ideal gas? (1) 50 K and 20 kPa (3) 750 K and 20 kPa (2) 50 K and 600 kPa (4) 750 K and 600 kPa N2O4(g) 2NO2(g) The measurable quantities of the gases at equilibrium must be (1) decreasing (2) increasing 18 A sample of oxygen gas is sealed in container X. A sample of hydrogen gas is sealed in container Z. Both samples have the same volume, temperature, and pressure. Which statement is true? (1) Container X contains more gas molecules than container Z. (2) Container X contains fewer gas molecules than container Z. (3) Containers X and Z both contain the same number of gas molecules. (4) Containers X and Z both contain the same mass of gas. P.S./Chem.–Aug. ’05 H (3) equal (4) constant 22 Atoms of which element can bond with each other to form ring and chain structures in compounds? (1) C (3) H (2) Ca (4) Na 23 In a voltaic cell, chemical energy is converted to (1) electrical energy, spontaneously (2) electrical energy, nonspontaneously (3) nuclear energy, spontaneously (4) nuclear energy, nonspontaneously [3] [OVER] 24 In each of the four beakers shown below, a 2.0-centimeter strip of magnesium ribbon reacts with 100 milliliters of HCl(aq) under the conditions shown. 0.1 M HCl 20°C 1.0 M HCl 20°C 0.1 M HCl 50°C 1.0 M HCl 50°C Beaker A Beaker B Beaker C Beaker D In which beaker will the reaction occur at the fastest rate? (1) A (2) B (3) C (4) D 25 Which aqueous solution is the best conductor of an electrical current? (3) 0.1 M CH3OH (1) 0.01 M CH3OH (2) 0.01 M KOH (4) 0.1 M KOH 29 Radioactive cobalt-60 is used in radiation therapy treatment. Cobalt-60 undergoes beta decay. This type of nuclear reaction is called (1) natural transmutation (2) artificial transmutation (3) nuclear fusion (4) nuclear fission 26 A hydrogen ion, H+, in aqueous solution may also be written as (3) H3O+ (1) H2O (2) H2O2 (4) OH– Note that question 30 has only three choices. 30 Given the balanced ionic equation: 27 One acid-base theory states that an acid is (1) an electron donor (3) an H+ donor (2) a neutron donor (4) an OH– donor 2Al(s) + 3Cu2+(aq) → 2Al3+(aq) + 3Cu(s) Compared to the total charge of the reactants, the total charge of the products is 28 Which isotope will spontaneously decay and emit particles with a charge of +2? (3) 198Au (1) 53Fe 137 (2) Cs (4) 220Fr P.S./Chem.–Aug. ’05 (1) less (2) greater (3) the same [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 38 Given the balanced equation: 31 The percentage by mass of Br in the compound AlBr3 is closest to (1) 10.% (3) 75% (2) 25% (4) 90.% AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(s) This reaction is classified as (1) (2) (3) (4) 32 Which symbol represents a particle with a total of 10 electrons? (1) N (3) Al 3+ (2) N (4) Al3+ 39 A solution contains 35 grams of KNO3 dissolved in 100 grams of water at 40°C. How much more KNO3 would have to be added to make it a saturated solution? (1) 29 g (3) 12 g (2) 24 g (4) 4 g 33 Which electron configuration represents an atom of aluminum in an excited state? (1) 2-7-4 (3) 2-8-3 (2) 2-7-7 (4) 2-8-6 34 At STP, an element that is a brittle solid and a poor conductor of heat and electricity could have an atomic number of (1) 12 (3) 16 (2) 13 (4) 17 40 Which diagram best represents a gas in a closed container? 35 Based on Reference Table S, atoms of which of these elements have the strongest attraction for the electrons in a chemical bond? (1) Al (3) P (2) Si (4) S 36 A sample of a compound contains 65.4 grams of zinc, 12.0 grams of carbon, and 48.0 grams of oxygen. What is the mole ratio of zinc to carbon to oxygen in this compound? (1) 1:1:2 (3) 1:4:6 (2) 1:1:3 (4) 5:1:4 (1) (3) (2) (4) 41 What is the total number of moles of NaCl(s) needed to make 3.0 liters of a 2.0 M NaCl solution? (1) 1.0 mol (3) 6.0 mol (2) 0.70 mol (4) 8.0 mol 37 Which process would most effectively separate two liquids with different molecular polarities? (1) filtration (3) distillation (2) fermentation (4) conductivity P.S./Chem.–Aug. ’05 synthesis decomposition single replacement double replacement [5] [OVER] 42 Which Lewis electron-dot diagram is correct for a S2– ion? S 2– (1) S S 47 Given the incomplete equation representing an organic addition reaction: X(g) + Cl2(g) → XCl2(g) 2– Which compound could be represented by X? 2– (2) S (3) C3H8 (4) C4H10 (1) CH4 (2) C2H4 (3) 2– 48 Given the incomplete equation: 4Fe + 3O2 → 2X (4) Which compound is represented by X? (3) Fe3O2 (4) Fe3O4 (1) FeO (2) Fe2O3 43 A student wants to prepare a 1.0-liter solution of a specific molarity. The student determines that the mass of the solute needs to be 30. grams. What is the proper procedure to follow? (1) Add 30. g of solute to 1.0 L of solvent. (2) Add 30. g of solute to 970. mL of solvent to make 1.0 L of solution. (3) Add 1000. g of solvent to 30. g of solute. (4) Add enough solvent to 30. g of solute to make 1.0 L of solution. 49 How are HNO3(aq) and CH3COOH(aq) similar? (1) They are Arrhenius acids and they turn blue litmus red. (2) They are Arrhenius acids and they turn red litmus blue. (3) They are Arrhenius bases and they turn blue litmus red. (4) They are Arrhenius bases and they turn red litmus blue. 44 What is the total number of joules released when a 5.00-gram sample of water changes from liquid to solid at 0°C? (1) 334 J (3) 2260 J (2) 1670 J (4) 11 300 J 50 The chart below shows the spontaneous nuclear decay of U-238 to Th-234 to Pa-234 to U-234. U 238 Mass Number 45 Which set of procedures and observations indicates a chemical change? (1) Ethanol is added to an empty beaker and the ethanol eventually disappears. (2) A solid is gently heated in a crucible and the solid slowly turns to liquid. (3) Large crystals are crushed with a mortar and pestle and become powder. (4) A cool, shiny metal is added to water in a beaker and rapid bubbling occurs. 236 234 Th Pa U 232 230 88 89 90 91 92 Atomic Number 46 At STP, a sample of which element has the highest entropy? (1) Na(s) (3) Br2() (2) Hg() (4) F2(g) P.S./Chem.–Aug. ’05 What is the correct order of nuclear decay modes for the change from U-238 to U-234? (1) (2) (3) (4) [6] β– decay, γ decay, β– decay β– decay, β– decay, α decay α decay, α decay, β– decay α decay, β– decay, β– decay Part B–2 Answer all questions in this part. Directions (51–67): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 In the space in your answer booklet, show a correct numerical setup for calculating the formula mass of glucose, C6H12O6. [1] 52 Write the empirical formula for the compound C6H12O6. [1] Base your answers to questions 53 through 55 on the potential energy diagram below. Potential Energy (kJ) 180 Without catalyst 160 With catalyst 140 120 100 80 60 40 20 0 Reaction Coordinate 53 What is the heat of reaction for the forward reaction? [1] 54 What is the activation energy for the forward reaction with the catalyst? [1] 55 Explain, in terms of the function of a catalyst, why the curves on the potential energy diagram for the catalyzed and uncatalyzed reactions are different. [1] Base your answers to questions 56 through 58 on the properties of propanone. 56 In the space in your answer booklet, draw the structural formula for propanone. [1] 57 Explain, in terms of molecular energy, why the vapor pressure of propanone increases when its temperature increases. [1] 58 A liquid’s boiling point is the temperature at which its vapor pressure is equal to the atmospheric pressure. Using Reference Table H, what is the boiling point of propanone at an atmospheric pressure of 70 kPa? [1] P.S./Chem.–Aug. ’05 [7] [OVER] Base your answers to questions 59 through 61 on the information below. Two isotopes of potassium are K-37 and K-42. 59 What is the total number of neutrons in the nucleus of a K-37 atom? [1] 60 How many valence electrons are in an atom of K-42 in the ground state? [1] 61 Explain, in terms of subatomic particles, why K-37 and K-42 are isotopes of potassium. [1] 62 A sample of oxygen gas in one container has a volume of 20.0 milliliters at 297 K and 101.3 kPa. The entire sample is transferred to another container where the temperature is 283 K and the pressure is 94.6 kPa. In the space in your answer booklet, show a correct numerical setup for calculating the new volume of this sample of oxygen gas. [1] 63 In the space in your answer booklet, draw a Lewis electron-dot diagram for a molecule of phosphorus trichloride, PCl3. [1] Base your answers to questions 64 through 67 on the table below. First Ionization Energy of Selected Elements Element Atomic Number First Ionization Energy (kJ/mol) lithium sodium potassium rubidium cesium 3 11 19 37 55 520 496 419 403 376 64 On the grid in your answer booklet, mark an appropriate scale on the axis labeled “First Ionization Energy (kJ/mol).” An appropriate scale is one that allows a trend to be seen. [1] 65 On the same grid, plot the data from the table. Circle and connect the points. [1] Example: 66 State the trend in first ionization energy for the elements in the table as the atomic number increases. [1] 67 Explain, in terms of atomic structure, why cesium has a lower first ionization energy than rubidium. [1] P.S./Chem.–Aug. ’05 [8] Part C Answer all questions in this part. Directions (68–85): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 68 through 70 on the information below. The decomposition of sodium azide, NaN3(s), is used to inflate airbags. On impact, the NaN3(s) is ignited by an electrical spark, producing N2(g) and Na(s). The N2(g) inflates the airbag. 68 Balance the equation in your answer booklet, using the smallest whole-number coefficients. [1] 69 What is the total number of moles present in a 52.0-gram sample of NaN3(s) (gramformula mass = 65.0 gram/mole)? [1] 70 An inflated airbag has a volume of 5.00 × 104 cm3 at STP. The density of N2(g) at STP is 0.00125 g/cm3. What is the total number of grams of N2(g) in the airbag? [1] Base your answers to questions 71 through 73 on the information below. Element X is a solid metal that reacts with chlorine to form a water-soluble binary compound. 71 State one physical property of element X that makes it a good material for making pots and pans. [1] 72 Explain, in terms of particles, why an aqueous solution of the binary compound conducts an electric current. [1] 73 The binary compound consists of element X and chlorine in a 1:2 molar ratio. What is the oxidation number of element X in this compound? [1] P.S./Chem.–Aug. ’05 [9] [OVER] Base your answers to questions 74 through 76 on the diagram and balanced equation below, which represent the electrolysis of molten NaCl. (+) Battery (–) Switch Positive electrode (anode) Negative electrode (cathode) Cl – Na+ Molten NaCl (810°C) 2NaCl Cl2 + 2Na 74 When the switch is closed, which electrode will attract the sodium ions? [1] 75 What is the purpose of the battery in this electrolytic cell? [1] 76 Write the balanced half-reaction for the reduction that occurs in this electrolytic cell. [1] Base your answers to questions 77 through 79 on the information below. In a titration, 3.00 M NaOH(aq) was added to an Erlenmeyer flask containing 25.00 milliliters of HCl(aq) and three drops of phenolphthalein until one drop of the NaOH(aq) turned the solution a light-pink color. The following data were collected by a student performing this titration. Initial NaOH(aq) buret reading: 14.45 milliliters Final NaOH(aq) buret reading: 32.66 milliliters 77 What is the total volume of NaOH(aq) that was used in this titration? [1] 78 In the space in your answer booklet, show a correct numerical setup for calculating the molarity of the HCl(aq). [1] 79 Based on the data given, what is the correct number of significant figures that should be shown in the molarity of the HCl(aq)? [1] P.S./Chem.–Aug. ’05 [10] Base your answers to questions 80 through 82 on the information below. A student was studying the pH differences in samples from two Adirondack streams. The student measured a pH of 4 in stream A and a pH of 6 in stream B. 80 Compare the hydronium ion concentration in stream A to the hydronium ion concentration in stream B. [1] 81 What is the color of bromthymol blue in the sample from stream A? [1] 82 Identify one compound that could be used to neutralize the sample from stream A. [1] Base your answers to questions 83 through 85 on the information below. The radioisotopes carbon-14 and nitrogen-16 are present in a living organism. Carbon-14 is commonly used to date a once-living organism. 83 Complete the nuclear equation in your answer booklet for the decay of C-14. Include both the atomic number and the mass number of the missing particle. [1] 84 Explain why N-16 is a poor choice for radioactive dating of a bone. [1] 85 A sample of wood is found to contain 18 as much C-14 as is present in the wood of a living tree. What is the approximate age, in years, of this sample of wood? [1] P.S./Chem.–Aug. ’05 [11] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Tuesday, August 16, 2005 — 12:30 to 3:30 p.m., only ANSWER SHEET ■ Male ■ Female Grade Student .............................................. Sex: ........... Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York PHYSICAL SETTING CHEMISTRY Tuesday, August 16, 2005 — 12:30 to 3:30 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part REGENTS HIGH SCHOOL EXAMINATION A 30 B–1 20 B–2 17 C 18 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only Part B–2 51 51 52 52 53 kJ 53 54 kJ 54 55 55 [1] [OVER] For Raters Only 56 56 57 57 58 °C 58 59 59 60 60 61 61 [2] For Raters Only 62 62 63 63 [3] [OVER] For Raters Only 64 and 65 First Ionization Energy (kJ/mol) First Ionization Energy Versus Atomic Number of Selected Elements 64 65 3 7 11 15 19 23 27 31 35 39 43 47 51 55 Atomic Number 66 66 67 67 Total Score for Part B–2 [4] For Raters Only Part C 68 NaN3(s) → Na(s) + 68 N2(g) 69 mol 69 70 g 70 71 71 72 72 73 73 74 74 75 75 76 76 [5] [OVER] For Raters Only 77 mL 77 78 78 79 79 80 80 81 81 82 82 83 14 6 C→ + – 01 e 83 84 84 85 y 85 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 26, 2006 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 The element in Group 14, Period 3 on the Periodic Table is classified as a (1) metal (3) metalloid (2) noble gas (4) nonmetal 1 Which two nuclides are isotopes of the same element? (1) 20 Na 11 (2) 39 19K and 20 10Ne and 40 20Ca (3) 39 K 19 and 42 19K (4) 14C 6 and 147N 7 Which trends are observed when the elements in Period 3 on the Periodic Table are considered in order of increasing atomic number? (1) The atomic radius decreases, and the first ionization energy generally increases. (2) The atomic radius decreases, and the first ionization energy generally decreases. (3) The atomic radius increases, and the first ionization energy generally increases. (4) The atomic radius increases, and the first ionization energy generally decreases. 2 An atom of oxygen is in an excited state. When an electron in this atom moves from the third shell to the second shell, energy is (1) emitted by the nucleus (2) emitted by the electron (3) absorbed by the nucleus (4) absorbed by the electron 3 The charge of a beryllium-9 nucleus is (1) +13 (3) +5 (2) +9 (4) +4 8 What is the chemical formula for sodium sulfate? (1) Na2SO3 (3) NaSO3 (2) Na2SO4 (4) NaSO4 4 Which sequence represents a correct order of historical developments leading to the modern model of the atom? (1) the atom is a hard sphere → most of the atom is empty space → electrons exist in orbitals outside the nucleus (2) the atom is a hard sphere → electrons exist in orbitals outside the nucleus → most of the atom is empty space (3) most of the atom is empty space → electrons exist in orbitals outside the nucleus → the atom is a hard sphere (4) most of the atom is empty space → the atom is a hard sphere → electrons exist in orbitals outside the nucleus 9 Given the structural formula: H H H H HO C C C C OH H H What is the empirical formula of this compound? (1) CH3O (2) C2H5O 5 Which statement describes a chemical property of oxygen? (1) Oxygen has a melting point of 55 K. (2) Oxygen can combine with a metal to produce a compound. (3) Oxygen gas is slightly soluble in water. (4) Oxygen gas can be compressed. P.S./Chem.–Jan. ’06 H H (3) C4H10O2 (4) C8H20O4 10 Which chemical equation is correctly balanced? (1) (2) (3) (4) [2] H2(g) + O2(g) → H2O(g) N2(g) + H2(g) → NH3(g) 2NaCl(s) → Na(s) + Cl2(g) 2KCl(s) → 2K(s) + Cl2(g) 11 Compared to a calcium atom, the calcium ion Ca2+ has (1) more protons (3) more electrons (2) fewer protons (4) fewer electrons 18 Given the balanced equation: I2(s) + energy → I2(g) As a sample of I2(s) sublimes to I2(g), the entropy of the sample (1) increases because the particles are less randomly arranged (2) increases because the particles are more randomly arranged (3) decreases because the particles are less randomly arranged (4) decreases because the particles are more randomly arranged 12 Which type of bond is found in sodium bromide? (1) covalent (3) ionic (2) hydrogen (4) metallic 13 Which substance can not be decomposed by ordinary chemical means? (1) methane (3) ethanol (2) mercury (4) ammonia 19 The multiple covalent bond in 1-butene is a (1) double covalent bond that electrons (2) double covalent bond that electrons (3) triple covalent bond that electrons (4) triple covalent bond that electrons 14 A mixture of crystals of salt and sugar is added to water and stirred until all solids have dissolved. Which statement best describes the resulting mixture? (1) The mixture is homogeneous and can be separated by filtration. (2) The mixture is homogeneous and cannot be separated by filtration. (3) The mixture is heterogeneous and can be separated by filtration. (4) The mixture is heterogeneous and cannot be separated by filtration. a molecule of has 6 shared has 4 shared has 6 shared has 4 shared 20 In an oxidation-reduction reaction, reduction is defined as the (1) loss of protons (3) loss of electrons (2) gain of protons (4) gain of electrons 15 Under which conditions of temperature and pressure would a sample of H2(g) behave most like an ideal gas? (1) 0°C and 100 kPa (2) 0°C and 300 kPa (3) 150°C and 100 kPa (4) 150°C and 300 kPa 21 What is the oxidation number assigned to manganese in KMnO4? (1) +7 (3) +3 (2) +2 (4) +4 22 Which of the following aqueous solutions is the best conductor of electricity? (3) 0.10 M NaOH (1) 0.10 M CH3OH (2) 1.0 M CH3OH (4) 1.0 M NaOH 16 In a chemical reaction, the difference between the potential energy of the products and the potential energy of the reactants is defined as the (1) activation energy (2) ionization energy (3) heat of reaction (4) heat of vaporization 23 One acid-base theory states that an acid is – + (3) an H donor (1) an H donor – + (2) an H acceptor (4) an H acceptor 17 Which substance is an Arrhenius base? (1) KCl (3) KOH (2) CH3Cl (4) CH3OH P.S./Chem.–Jan. ’06 [3] [OVER] 28 Which structural formula is correct for 2-methyl-3-pentanol? 24 Positrons are spontaneously emitted from the nuclei of (1) potassium-37 (3) nitrogen-16 (2) radium-226 (4) thorium-232 H H 25 The amount of energy released from a fission reaction is much greater than the energy released from a chemical reaction because in a fission reaction (1) mass is converted into energy (2) energy is converted into mass (3) ionic bonds are broken (4) covalent bonds are broken H H H C C C H H H H H C C C H H H H H H H C H H OH C C C C H H H H H C H OH H (1) (3) H 26 Which Lewis electron-dot diagram is correct for CO2? H O C O (1) O C O O C O (2) (4) C C H H H H H H C C C H H (2) H H H H H H C C C C H H H OH H C H H (4) Note that questions 29 and 30 have only three choices. 29 When an atom becomes a positive ion, the radius of the atom (1) decreases (2) increases (3) remains the same 27 Types of nuclear reactions include fission, fusion, and (1) single replacement (2) neutralization (3) oxidation-reduction (4) transmutation P.S./Chem.–Jan. ’06 C OH (3) O C O H H 30 Compared to the freezing point of 1.0 M KCl(aq) at standard pressure, the freezing point of 1.0 M CaCl2(aq) at standard pressure is (1) lower (2) higher (3) the same [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 34 The atomic mass of element A is 63.6 atomic mass units. The only naturally occurring isotopes of element A are A-63 and A-65. The percent abundances in a naturally occurring sample of element A are closest to (1) 31% A-63 and 69% A-65 (2) 50% A-63 and 50% A-65 (3) 69% A-63 and 31% A-65 (4) 100% A-63 and 0% A-65 31 Which electron configuration represents the electrons in an atom of chlorine in an excited state? (1) 2-7-7 (3) 2-8-7 (2) 2-7-8 (4) 2-8-8 32 Given the particle diagram representing four molecules of a substance: 35 Elements Q, X, and Z are in the same group on the Periodic Table and are listed in order of increasing atomic number. The melting point of element Q is –219°C and the melting point of element Z is –7°C. Which temperature is closest to the melting point of element X? (1) –7°C (3) –219°C (2) –101°C (4) –226°C Which particle diagram best represents this same substance after a physical change has taken place? 36 Given the balanced equation: 2C + 3H2 → C2H6 (1) What is the total number of moles of C that must completely react to produce 2.0 moles of C2H6? (3) (1) 1.0 mol (2) 2.0 mol (3) 3.0 mol (4) 4.0 mol 37 Given the balanced equation: 2KClO3 → 2KCl + 3O2 Which type of reaction is represented by this equation? (2) (4) (1) (2) (3) (4) 33 What is the percent composition by mass of nitrogen in NH4NO3 (gram-formula mass = 80.0 grams/mole)? (1) 17.5% (3) 52.5% (2) 35.0% (4) 60.0% P.S./Chem.–Jan. ’06 [5] synthesis decomposition single replacement double replacement [OVER] 38 A solid substance was tested in the laboratory. The test results are listed below. • dissolves in water • is an electrolyte • melts at a high temperature 43 Given the potential energy diagram for a chemical reaction: 60. 50. (1) Cu (2) CuBr2 Potential Energy (kJ) Based on these results, the solid substance could be (3) C (4) C6H12O6 39 If 0.025 gram of Pb(NO3)2 is dissolved in 100. grams of H2O, what is the concentration of the resulting solution, in parts per million? (3) 250 ppm (1) 2.5 × 10–4 ppm (2) 2.5 ppm (4) 4.0 × 103 ppm 40. 30. 20. 10. 0 Reaction Coordinate 40 Given the balanced equation: 4Fe(s) + 3O2(g) → 2Fe2O3(s) + 1640 kJ Which statement correctly describes the energy changes that occur in the forward reaction? Which phrase best describes this reaction? (1) (2) (3) (4) endothermic with ∆H = +1640 kJ endothermic with ∆H = –1640 kJ exothermic with ∆H = +1640 kJ exothermic with ∆H = –1640 kJ (1) The activation energy is reaction is endothermic. (2) The activation energy is reaction is exothermic. (3) The activation energy is reaction is endothermic. (4) The activation energy is reaction is exothermic. 41 A student adds solid KCl to water in a flask. The flask is sealed with a stopper and thoroughly shaken until no more solid KCl dissolves. Some solid KCl is still visible in the flask. The solution in the flask is (1) saturated and is at equilibrium with the solid KCl (2) saturated and is not at equilibrium with the solid KCl (3) unsaturated and is at equilibrium with the solid KCl (4) unsaturated and is not at equilibrium with the solid KCl H O H C C H 50. kJ and the 50. kJ and the H N H This compound is classified as an (1) amide (2) amine (3) aldehyde (4) alcohol 45 Which formula represents an unsaturated hydrocarbon? (1) CH2CHCl (3) CH3CH2CH3 (2) CH3CH2Cl (4) CH3CHCH2 2C2H6 + 7O2 → 4CO2 + 6 ____ What is the formula of the missing product? P.S./Chem.–Jan. ’06 10. kJ and the 44 Given the structural formula: 42 Given the incomplete equation for the combustion of ethane: (1) CH3OH (2) HCOOH 10. kJ and the (3) H2O (4) H2O2 [6] 49 Given the nuclear equation: 46 Given the balanced equation for an organic reaction: 1H 1 C2H2 + 2Cl2 → C2H2Cl4 + X → 63Li + 42He This reaction is best classified as The particle represented by X is (1) addition (2) esterification (1) 94Li (3) (2) 94Be (4) (3) fermentation (4) substitution 47 Which indicator is yellow in a solution with a pH of 9.8? (1) methyl orange (3) bromcresol green (2) bromthymol blue (4) thymol blue 10 Be 5 10 C 6 50 The decay of which radioisotope can be used to estimate the age of the fossilized remains of an insect? (1) Rn-222 (3) Co-60 (2) I-131 (4) C-14 48 How many milliliters of 0.100 M NaOH(aq) would be needed to completely neutralize 50.0 milliliters of 0.300 M HCl(aq)? (1) 16.7 mL (3) 150. mL (2) 50.0 mL (4) 300. mL P.S./Chem.–Jan. ’06 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–67): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 What is the total number of neutrons in an atom of aluminum-27? [1] 52 Explain, in terms of atomic structure, why the atomic radius of iodine is greater than the atomic radius of fluorine. [1] 53 In the space in your answer booklet, draw a Lewis electron-dot diagram of a selenium atom in the ground state. [1] 54 Explain, in terms of atomic structure, why liquid mercury is a good electrical conductor. [1] 55 Given the structural formula of pentane: H H H H H H C C C C C H H H H H H In the space in your answer booklet, draw a structural formula for an isomer of pentane. [1] 56 Based on Reference Table N, what is the fraction of a sample of potassium-42 that will remain unchanged after 62.0 hours? [1] 57 What is the total number of moles in 80.0 grams of C2H5Cl (gram-formula mass = 64.5 grams/mole)? [1] 58 What is the total amount of heat energy, in joules, absorbed by 25.0 grams of water when the temperature of the water increases from 24.0°C to 36.0°C? [1] Base your answers to questions 59 and 60 on the information and balanced equation below. Given the equation for a reaction at equilibrium: 2SO2(g) + O2(g) 2SO3(g) + energy 59 Explain, in terms of LeChatelier’s principle, why the concentration of SO2(g) increases when the temperature is increased. [1] 60 Explain, in terms of collisions between molecules, why increasing the concentration of O2(g) produces a decrease in the concentration of SO2(g). [1] P.S./Chem.–Jan. ’06 [8] Base your answers to questions 61 through 65 on the table below. Physical Properties of Four Gases Name of Gas Molecular Structure Boiling Point (K) at 1 Atm Density (g/L) at STP hydrogen hydrogen chloride hydrogen bromide hydrogen iodide H–H H–Cl H–Br H–I 20. 188 207 237 0.0899 1.64 ? 5.66 61 The volume of 1.00 mole of hydrogen bromide at STP is 22.4 liters. The gram-formula mass of hydrogen bromide is 80.9 grams per mole. What is the density of hydrogen bromide at STP? [1] 62 The density of hydrogen at STP is 0.0899 gram per liter. Express this density to two significant figures. [1] 63 Explain, in terms of electronegativity difference, why the bond in H–Cl is more polar than the bond in H–I. [1] 64 Explain, in terms of intermolecular forces, why hydrogen has a lower boiling point than hydrogen bromide. [1] 65 Explain, in terms of molecular polarity, why hydrogen chloride is more soluble than hydrogen in water under the same conditions of temperature and pressure. [1] Base your answers to questions 66 and 67 on the graph below, which represents the cooling of a substance starting at a temperature above its boiling point. 200 Temperature (°C) 180 160 A 140 120 100 C B 80 60 40 E D 20 F 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Time (min) 66 What is the melting point of this substance? [1] 67 Which segment of the graph represents the gas phase, only? P.S./Chem.–Jan. ’06 [9] [1] [OVER] Part C Answer all questions in this part. Directions (68–85): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 68 through 70 on the information and table below. A student conducts an experiment to determine how the temperature of water affects the rate at which an antacid tablet dissolves in the water. The student has three antacid tablets of the same size and composition. The student drops one tablet into each of three beakers containing 200. milliliters of water at different temperatures and measures the time it takes for each tablet to completely dissolve. The results are shown in the table below. Dissolving Data for Three Antacid Tablets Beaker Original Temperature of Water (°C) Time for Tablet to Dissolve (s) 1 20. 40. 2 30. 25 3 40. 10. 68 Describe the effect of water temperature on the rate of dissolving. [1] 69 Explain, in terms of collision theory, how water temperature influences the rate of dissolving. [1] 70 What change, other than temperature, would affect the rate of dissolving? P.S./Chem.–Jan. ’06 [10] [1] Base your answers to questions 71 through 74 on the passage below. Acid rain lowers the pH in ponds and lakes and over time can cause the death of some aquatic life. Acid rain is caused in large part by the burning of fossil fuels in power plants and by gasoline-powered vehicles. The acids commonly associated with acid rain are sulfurous acid, sulfuric acid, and nitric acid. In general, fish can tolerate a pH range between 5 and 9. However, even small changes in pH can significantly affect the solubility and toxicity of common pollutants. Increased concentrations of these pollutants can adversely affect the behavior and normal life processes of fish and cause deformity, lower egg production, and less egg hatching. 71 Acid rain caused the pH of a body of water to decrease. Explain this pH decrease in terms of the change in concentration of hydronium ions. [1] 72 Write the chemical formula of a negative polyatomic ion present in an aqueous nitric acid solution. [1] 73 Using information in the passage, describe one effect of acid rain on future generations of fish species in ponds and lakes. [1] 74 Sulfur dioxide, SO2, is one of the gases that reacts with water to produce acid rain. According to Reference Table G, describe how the solubility of sulfur dioxide in water is affected by an increase in water temperature. [1] Base your answers to questions 75 through 77 on the information below. A student is instructed to make 0.250 liter of a 0.200 M aqueous solution of Ca(NO3)2. 75 What is the gram-formula mass of Ca(NO3)2? [1] 76 In the space in your answer booklet, show a correct numerical setup for calculating the total number of moles of Ca(NO3)2 needed to make 0.250 liter of the 0.200 M calcium nitrate solution. [1] 77 In order to prepare the described solution in the laboratory, two quantities must be measured accurately. One of these quantities is the volume of the solution. What other quantity must be measured to prepare this solution? [1] P.S./Chem.–Jan. ’06 [11] [OVER] Base your answers to questions 78 through 80 on the data in Reference Table S. 78 On the data table in your answer booklet, record the boiling points for He, Ne, Ar, Kr, and Xe. [1] 79 On the grid in your answer booklet, plot the boiling point versus the atomic number for He, Ne, Ar, Kr, and Xe. Circle and connect the points. [1] Example: 80 Based on your graph, describe the trend in the boiling points of these elements as the atomic number increases. [1] Base your answers to questions 81 and 82 on the information below. A lightbulb contains argon gas at a temperature of 295 K and at a pressure of 75 kilopascals. The lightbulb is switched on, and after 30 minutes its temperature is 418 K. 81 In the space in your answer booklet, show a correct numerical setup for calculating the pressure of the gas inside the lightbulb at 418 K. Assume the volume of the lightbulb remains constant. [1] 82 What Celsius temperature is equal to 418 K? [1] 83 Because tap water is slightly acidic, water pipes made of iron corrode over time, as shown by the balanced ionic equation below: 2Fe + 6H+ → 2Fe3+ + 3H2 Explain, in terms of chemical reactivity, why copper pipes are less likely to corrode than iron pipes. [1] P.S./Chem.–Jan. ’06 [12] Base your answers to questions 84 and 85 on the information and diagram below. The apparatus shown in the diagram consists of two inert platinum electrodes immersed in water. A small amount of an electrolyte, H2SO4, must be added to the water for the reaction to take place. The electrodes are connected to a source that supplies electricity. O (g) H (g) 2 2 H O( ) + H SO (aq) 2 Platinum electrode 2 4 Platinum electrode (+) (–) Battery 84 What type of electrochemical cell is shown? [1] 85 What particles are provided by the electrolyte that allow an electric current to flow? [1] P.S./Chem.–Jan. ’06 [13] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Thursday, January 26, 2006 — 1:15 to 4:15 p.m., only ANSWER SHEET ■ Male ■ Female Grade . . . . . . . . . . . . Student .............................................. Sex: Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 26, 2006 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ■ Male Sex: ■ Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 17 C 18 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 51 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only 51 52 52 53 53 For Raters Only 54 54 55 55 56 56 57 mol 57 58 J 58 59 59 60 60 [2] For Raters Only 61 g/L 61 62 g/L 62 63 63 64 64 65 65 66 °C 66 67 67 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 68 68 69 69 70 70 71 71 72 72 73 73 74 74 [4] For Raters Only 75 g/mol 75 76 76 77 77 GO RIGHT ON TO THE NEXT PAGE [5] ➪ [OVER] For Raters Only 78 Data Table Symbol 79 Atomic Number Boiling Point (K) He 2 Ne 10 Ar 18 Kr 36 Xe 54 78 Boiling Point Versus Atomic Number for He, Ne, Ar, Kr, and Xe 200. Boiling Point (K) 150. 79 100. 50. 0 0 20 40 60 Atomic Number 80 80 [6] For Raters Only 81 81 82 82 °C 83 83 84 84 85 85 Total Score for Part C [7] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 21, 2006 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 Given the balanced equation representing a reaction: 1 Which notation represents an atom of sodium with an atomic number of 11 and a mass number of 24? (1) 24 (3) 13 11Na 11Na (2) 11Na 24 (4) F2(g) + H2(g) → 2HF(g) What is the mole ratio of H2(g) to HF(g) in this reaction? 35Na 11 (1) 1:1 (2) 1:2 2 Which element has chemical properties that are most similar to those of calcium? (1) Co (3) N (2) K (4) Sr 8 Which list includes three types of chemical reactions? (1) condensation, double replacement, and sublimation (2) condensation, solidification, and synthesis (3) decomposition, double replacement, and synthesis (4) decomposition, solidification, and sublimation 3 Which element is malleable and can conduct electricity in the solid phase? (1) iodine (3) sulfur (2) phosphorus (4) tin 4 Atoms of different isotopes of the same element differ in their total number of (1) electrons (3) protons (2) neutrons (4) valence electrons 5 Which statement correctly describes of oxygen, O2 and O3? (1) They have identical molecular and identical properties. (2) They have identical molecular and different properties. (3) They have different molecular and identical properties. (4) They have different molecular and different properties. 9 Which type of bond results when one or more valence electrons are transferred from one atom to another? (1) a hydrogen bond (2) an ionic bond (3) a nonpolar covalent bond (4) a polar covalent bond two forms structures 10 What is the total number of electrons shared in the bonds between the two carbon atoms in a molecule of H C C H ? (1) 6 (3) 3 (2) 2 (4) 8 structures structures structures 11 Which formula represents a nonpolar molecule? (1) CH4 (3) H2O (2) HCl (4) NH3 6 What is the IUPAC name for the compound FeS? (1) iron(II) sulfate (3) iron(II) sulfide (2) iron(III) sulfate (4) iron(III) sulfide P.S./Chem.–June ’06 (3) 2:1 (4) 2:3 [2] 18 Which expression represents the ΔH for a chemical reaction in terms of the potential energy, PE, of its products and reactants? (1) PE of products + PE of reactants (2) PE of products – PE of reactants (3) PE of products × PE of reactants (4) PE of products ÷ PE of reactants 12 Which changes occur as a cadmium atom, Cd, becomes a cadmium ion, Cd2+? (1) The Cd atom gains two electrons and its radius decreases. (2) The Cd atom gains two electrons and its radius increases. (3) The Cd atom loses two electrons and its radius decreases. (4) The Cd atom loses two electrons and its radius increases. 19 Which balanced equation represents an endothermic reaction? (1) C(s) + O2(g) → CO2(g) (2) CH4(g) + 2O2(g) → CO2(g) + 2H2O(ᐉ) (3) N2(g) + 3H2(g) → 2NH3(g) (4) N2(g) + O2(g) → 2NO(g) 13 Which element has atoms with the greatest attraction for electrons in a chemical bond? (1) beryllium (3) lithium (2) fluorine (4) oxygen 20 Which formula represents propyne? (3) C5H8 (1) C3H4 (2) C3H6 (4) C5H10 14 Two substances, A and Z, are to be identified. Substance A can not be broken down by a chemical change. Substance Z can be broken down by a chemical change. What can be concluded about these substances? (1) Both substances are elements. (2) Both substances are compounds. (3) Substance A is an element and substance Z is a compound. (4) Substance A is a compound and substance Z is an element. 21 Which factors must be equal in a reversible chemical reaction at equilibrium? (1) the activation energies of the forward and reverse reactions (2) the rates of the forward and reverse reactions (3) the concentrations of the reactants and products (4) the potential energies of the reactants and products 15 Which ion, when combined with chloride ions, Cl–, forms an insoluble substance in water? (3) Pb2+ (1) Fe2+ 2+ (2) Mg (4) Zn2+ 22 The compounds CH3OCH3 and CH3CH2OH are isomers of each other. These two compounds must have the same (1) density (3) melting point (2) reactivity (4) molecular formula 16 Molarity is defined as the (1) moles of solute per kilogram of solvent (2) moles of solute per liter of solution (3) mass of a solution (4) volume of a solvent 23 Which balanced equation represents a redox reaction? (1) AgNO3 + NaCl → AgCl + NaNO3 (2) BaCl2 + K2CO3 → BaCO3 + 2KCl (3) CuO + CO → Cu + CO2 (4) HCl + KOH → KCl + H2O 17 Which formula represents a hydrocarbon? (1) CH3CH2CH2CHO (2) CH3CH2CH2CH3 (3) CH3CH2CH2COOH (4) CH3CH2COOCH3 P.S./Chem.–June ’06 [3] [OVER] 24 Which process occurs at the anode in an electrochemical cell? (1) the loss of protons (2) the loss of electrons (3) the gain of protons (4) the gain of electrons 28 Which equation represents the radioactive decay of 226 88Ra? (1) (2) (3) (4) 25 Which substance is an electrolyte? (1) CH3OH (3) H2O (2) C6H12O6 (4) KOH 4 → 222 86Rn + 2He 0 → 226 89Ac +–1e 0 → 226 87Fr ++1e 1 → 225 88Ra + 0n 29 Which type of reaction converts one element to another element? (1) neutralization (3) substitution (2) polymerization (4) transmutation 26 Which ion is the only negative ion present in an aqueous solution of an Arrhenius base? (1) hydride ion (3) hydronium ion (2) hydrogen ion (4) hydroxide ion 30 Which nuclear emission has the greatest mass? (1) α (3) – (2) γ (4) + 27 According to Reference Table N, which pair of isotopes spontaneously decays? (1) C-12 and N-14 (3) C-14 and N-14 (2) C-12 and N-16 (4) C-14 and N-16 P.S./Chem.–June ’06 226Ra 88 226Ra 88 226Ra 88 226Ra 88 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 36 A metal, M, forms an oxide compound with the general formula M2O. In which group on the Periodic Table could metal M be found? (1) Group 1 (3) Group 16 (2) Group 2 (4) Group 17 31 Which trends are observed as each of the elements within Group 15 on the Periodic Table is considered in order from top to bottom? (1) Their metallic properties decrease and their atomic radii decrease. (2) Their metallic properties decrease and their atomic radii increase. (3) Their metallic properties increase and their atomic radii decrease. (4) Their metallic properties increase and their atomic radii increase. 37 Given the key: Key = Atom of oxygen = Atom of carbon 32 What is the total number of electrons in a S2– ion? (1) 10 (3) 16 (2) 14 (4) 18 Which particle diagram represents a sample containing the compound CO(g)? 33 A substance has an empirical formula of CH2 and a molar mass of 56 grams per mole. The molecular formula for this compound is (3) C4H8 (1) CH2 (2) C4H6 (4) C8H4 (1) (3) (2) (4) 34 Compared to an atom of phosphorus-31, an atom of sulfur-32 contains (1) one less neutron (3) one more neutron (2) one less proton (4) one more proton 35 In which compound is the percent composition by mass of chlorine equal to 42%? (1) HClO (gram-formula mass = 52 g/mol) (2) HClO2 (gram-formula mass = 68 g/mol) (3) HClO3 (gram-formula mass = 84 g/mol) (4) HClO4 (gram-formula mass = 100. g/mol) P.S./Chem.–June ’06 38 At standard pressure, which element has a melting point higher than standard temperature? (3) Fe (1) F2 (2) Br2 (4) Hg [5] [OVER] 45 Given the formula: 39 Which Lewis electron-dot diagram represents chloroethene? H H H C C Cl H H H C C Cl H H (1) (3) H H H C C Cl H H C Cl H (2) H H H O H C C C C H N H H H H This compound is classified as (1) an aldehyde (2) an amide (3) an amine (4) a ketone 46 Given the balanced equation with an unknown compound represented by X: C6H12O6(aq) (4) enzyme 2X + 2CO2(g) Which compound is represented by X? 40 A saturated solution of NaNO3 is prepared at 60.°C using 100. grams of water. As this solution is cooled to 10.°C, NaNO3 precipitates (settles) out of the solution. The resulting solution is saturated. Approximately how many grams of NaNO3 settled out of the original solution? (1) 46 g (3) 85 g (2) 61 g (4) 126 g (1) (2) (3) (4) CH3OH(aq) CH2(OH)4(aq) CH3CH2OH(aq) CH2OHCH2OH(aq) 47 Which reactants form the salt CaSO4(s) in a neutralization reaction? (1) (2) (3) (4) 41 Which kelvin temperature is equivalent to –24°C? (1) 226 K (3) 273 K (2) 249 K (4) 297 K H2S(g) and Ca(ClO4)2(s) H2SO3(aq) and Ca(NO3)2(aq) H2SO4(aq) and Ca(OH)2(aq) SO2(g) and CaO(s) 42 Which substance has the lowest vapor pressure at 75°C? (1) water (3) propanone (2) ethanoic acid (4) ethanol 48 A student tested a 0.1 M aqueous solution and made the following observations: • conducts electricity • turns blue litmus to red • reacts with Zn(s) to produce gas bubbles 43 What is the IUPAC name for the compound that has the condensed structural formula CH3CH2CH2CHO? (1) butanal (3) propanal (2) butanol (4) propanol Which compound could be the solute in this solution? (1) CH3OH (2) LiBr 49 What is the half-life of sodium-25 if 1.00 gram of a 16.00-gram sample of sodium-25 remains unchanged after 237 seconds? (1) 47.4 s (3) 79.0 s (2) 59.3 s (4) 118 s 44 What volume of 0.500 M HNO3(aq) must completely react to neutralize 100.0 milliliters of 0.100 M KOH(aq)? (1) 10.0 mL (3) 50.0 mL (2) 20.0 mL (4) 500. mL P.S./Chem.–June ’06 (3) HBr (4) LiOH [6] 50 Given the table below that shows students’ examples of proposed models of the atom: Proposed Models of the Atom Model Location of Protons Location of Electrons A in the nucleus specific shells B in the nucleus regions of most probable location C dispersed throughout the atom specific shells D dispersed throughout the atom regions of most probable location Which model correctly describes the locations of protons and electrons in the wave-mechanical model of the atom? (1) A (3) C (2) B (4) D P.S./Chem.–June ’06 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–66): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 and 52 on the balanced equation below. Fe(s) + 2HNO3(aq) → Fe(NO3)2(aq) + H2(g) 51 What is the total number of oxygen atoms represented in the formula of the iron compound produced? [1] 52 Explain, using information from Reference Table J, why this reaction is spontaneous. [1] Base your answers to questions 53 and 54 on the information below. An atom has an atomic number of 9, a mass number of 19, and an electron configuration of 2–6–1. 53 What is the total number of neutrons in this atom? [1] 54 Explain why the number of electrons in the second and third shells shows that this atom is in an excited state. [1] 55 To which homologous series does CH3CH2CH2CH3 belong? [1] 56 What is the mass of 4.76 moles of Na3PO4 (gram-formula mass = 164 grams/mole)? [1] Base your answers to questions 57 and 58 on the information below. Given the balanced equation for dissolving NH4Cl(s) in water: NH4Cl(s) H2O + NH4 (aq) + Cl–(aq) 57 A student is holding a test tube containing 5.0 milliliters of water. When a sample of NH4Cl(s) is placed in the test tube, the test tube feels colder to the student’s hand. Describe the direction of heat flow between the test tube and the hand. [1] 58 Using the key in your answer booklet, draw at least two water molecules in the box, showing the correct orientation of each water molecule when it is near the Cl– ion in the aqueous solution. [1] P.S./Chem.–June ’06 [8] Base your answers to questions 59 and 60 on the information below. Given the reaction at equilibrium: 2NO2(g) N2O4(g) + 55.3 kJ 59 Explain, in terms of energy, why the forward reaction is exothermic. [1] 60 Explain, in terms of Le Chatelier’s principle, why the equilibrium shifts to the right to relieve the stress when the pressure on the system is increased at constant temperature. [1] Base your answers to questions 61 through 63 on the information below. Given the balanced equation for an organic reaction between butane and chlorine that takes place at 300.°C and 101.3 kilopascals: C4H10 + Cl2 → C4H9Cl + HCl 61 Identify the type of organic reaction shown. [1] 62 In the space in your answer booklet, draw a structural formula for the organic product. [1] 63 Explain, in terms of collision theory, why the rate of the reaction would decrease if the temperature of the reaction mixture was lowered to 200.°C with pressure remaining unchanged. [1] Base your answers to questions 64 through 66 on the information below. Ethanol, C2H5OH, is a volatile and flammable liquid with a distinct odor at room temperature. Ethanol is soluble in water. The boiling point of ethanol is 78.2°C at 1 atmosphere. Ethanol can be used as a fuel to produce heat energy, as shown by the balanced equation below. C2H5OH(ᐉ) + 3O2(g) → 2CO2(g) + 3H2O(ᐉ) + 1367 kJ 64 At 1 atmosphere, compare the boiling point of pure ethanol to the boiling point of a solution in which a nonvolatile substance is dissolved in ethanol. [1] 65 Determine the total amount of heat produced by the complete combustion of 2.00 moles of ethanol. [1] 66 Identify one physical property of ethanol, stated in the passage, that can be explained in terms of chemical bonds and intermolecular forces. [1] P.S./Chem.–June ’06 [9] [OVER] Part C Answer all questions in this part. Directions (67–84): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 67 and 68 on the information below. The graph shows the relationship between the solubility of a sequence of primary alcohols in water and the total number of carbon atoms in a molecule of the corresponding alcohol at the same temperature and pressure. A primary alcohol has the – OH group located on an end carbon of the hydrocarbon chain. Solubility Versus Total Number of Carbon Atoms Solubility (g/110. g of water) 9 8 7 6 5 4 3 2 1 0 3 4 5 6 7 8 9 10 11 Total Number of Carbon Atoms Adapted from Chemistry, Collins Educational Publishing, pp. 227-231 67 Describe the relationship between the solubility of a primary alcohol in water and the total number of carbon atoms in the primary alcohol. [1] 68 Determine the total mass of 1-pentanol that will dissolve in 110. grams of water to produce a saturated solution. [1] P.S./Chem.–June ’06 [10] Base your answers to questions 69 and 70 on the information below. Air bags are an important safety feature in modern automobiles. An air bag is inflated in milliseconds by the explosive decomposition of NaN3(s). The decomposition reaction produces N2(g), as well as Na(s), according to the unbalanced equation below. NaN3(s) → Na(s) + N2(g) 69 Balance the equation in your answer booklet for the decomposition of NaN3, using the smallest whole-number coefficients. [1] 70 When the air bag inflates, the nitrogen gas is at a pressure of 1.30 atmospheres, a temperature of 301 K, and has a volume of 40.0 liters. In the space in your answer booklet, calculate the volume of the nitrogen gas at STP. Your response must include both a correct numerical setup and the calculated volume. [2] Base your answers to questions 71 and 72 on the information below. A thiol is very similar to an alcohol, but a thiol has a sulfur atom instead of an oxygen atom in the functional group. One of the compounds in a skunk’s spray is 2-butene-1-thiol. The formula of this compound is shown below. H H H H C C C C SH H H H 71 Explain, in terms of composition, why this compound is a thiol. [1] 72 Explain, in terms of electron configuration, why oxygen atoms and sulfur atoms form compounds with similar molecular structures. [1] P.S./Chem.–June ’06 [11] [OVER] Base your answers to questions 73 through 75 on the graph below. The graph shows the relationship between pH value and hydronium ion concentration for common aqueous solutions and mixtures. pH Versus Hydronium Ion Concentration 14 Bleach 12 Aqueous ammonia Milk of magnesia 10. Seawater 8 pH Blood Milk 6 4 2 Tomato juice Lemon juice Stomach fluids (gastric juice) 0 100 10–2 10–4 10–6 10–8 10–10 10–12 10–14 Hydronium Ion Concentration (M) 73 What is the hydronium ion concentration of tomato juice? [1] 74 What color is thymol blue when added to milk of magnesia? [1] 75 According to this graph, which mixture is approximately 100 times more acidic than milk of magnesia? [1] P.S./Chem.–June ’06 [12] Base your answers to questions 76 and 77 on the information below. Archimedes (287–212 BC), a Greek inventor and mathematician, made several discoveries important to science today. According to a legend, Hiero, the king of Syracuse, commanded Archimedes to find out if the royal crown was made of gold, only. The king suspected that the crown consisted of a mixture of gold, tin, and copper. Archimedes measured the mass of the crown and the total amount of water displaced by the crown when it was completely submerged. He repeated the procedure using individual samples, one of gold, one of tin, and one of copper. Archimedes was able to determine that the crown was not made entirely of gold without damaging it. 76 Identify one physical property that Archimedes used in his comparison of the metal samples. [1] 77 Determine the volume of a 75-gram sample of gold at STP. [1] Base your answers to questions 78 through 81 on the information below. Aluminum is one of the most abundant metals in Earth’s crust. The aluminum compound found in bauxite ore is Al2O3. Over one hundred years ago, it was difficult and expensive to isolate aluminum from bauxite ore. In 1886, a brother and sister team, Charles and Julia Hall, found that molten (melted) cryolite, Na3AlF6, would dissolve bauxite ore. Electrolysis of the resulting mixture caused the aluminum ions in the Al2O3 to be reduced to molten aluminum metal. This less expensive process is known as the Hall process. 78 Write the oxidation state for each of the elements in cryolite. [1] 79 Write the balanced half-reaction equation for the reduction of Al3+ to Al. [1] 80 Explain, in terms of ions, why molten cryolite conducts electricity. [1] 81 Explain, in terms of electrical energy, how the operation of a voltaic cell differs from the operation of an electrolytic cell used in the Hall process. Include both the voltaic cell and the electrolytic cell in your answer. [1] P.S./Chem.–June ’06 [13] [OVER] Base your answers to questions 82 through 84 on the information below. A glass tube is filled with hydrogen gas at low pressure. An electric current is passed through the gas, causing it to emit light. This light is passed through a prism to separate the light into the bright, colored lines of hydrogen’s visible spectrum. Each colored line corresponds to a particular wavelength of light. One of hydrogen’s spectral lines is red light with a wavelength of 656 nanometers. Tubes filled with other gases produce different bright-line spectra that are characteristic of each kind of gas. These spectra have been observed and recorded. 82 Explain, in terms of electron energy states and energy changes, how hydrogen’s brightline spectrum is produced. [1] 83 Explain how the elements present on the surface of a star can be identified using brightline spectra. [1] 84 A student measured the wavelength of hydrogen’s visible red spectral line to be 647 nanometers. In the space in your answer booklet, show a correct numerical setup for calculating the student’s percent error. [1] P.S./Chem.–June ’06 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, June 21, 2006 — 1:15 to 4:15 p.m., only ANSWER SHEET I Male I Female Grade Student .............................................. Sex: ........... Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 21, 2006 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 16 C 19 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 51 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only 51 52 52 53 53 54 54 For Raters Only 55 55 56 g 56 57 57 58 Key = Hydrogen atom = Oxygen atom = Water molecule Cl – 58 59 59 60 60 [2] For Raters Only 61 61 62 62 63 63 64 64 65 kJ 65 66 66 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 67 67 68 69 68 g NaN3(s) → Na(s) + 69 N2(g) 70 70 L 71 71 72 72 [4] For Raters Only 73 73 M 74 74 75 75 76 76 cm3 77 78 Na3AlF6 77 Na: Al: 78 F: 79 79 80 80 81 81 [5] [OVER] For Raters Only 82 82 83 83 84 84 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, August 16, 2006 — 12:30 to 3:30 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 A compound is made up of iron and oxygen, only. The ratio of iron ions to oxide ions is 2:3 in this compound. The IUPAC name for this compound is (1) triiron dioxide (3) iron(III) oxide (2) iron(II) oxide (4) iron trioxide 1 Which statement correctly describes the charge of the nucleus and the charge of the electron cloud of an atom? (1) The nucleus is positive and the electron cloud is positive. (2) The nucleus is positive and the electron cloud is negative. (3) The nucleus is negative and the electron cloud is positive. (4) The nucleus is negative and the electron cloud is negative. 7 Which process is a chemical change? (1) melting of ice (2) boiling of water (3) subliming of ice (4) decomposing of water 2 Which Period 4 element has the most metallic properties? (1) As (3) Ge (2) Br (4) Sc 8 Which substance contains bonds that involved the transfer of electrons from one atom to another? (1) CO2 (3) KBr (2) NH3 (4) Cl2 3 Which property makes it possible to separate the oxygen and the nitrogen from a sample of liquefied air? (1) boiling point (3) hardness (2) conductivity (4) electronegativity 9 What is the total number of pairs of electrons shared in a molecule of N2? (1) one pair (3) three pairs (2) two pairs (4) four pairs 4 Which statement explains why ozone gas, O3, and oxygen gas, O2, have different properties? (1) They are formed from different elements. (2) They have different molecular structures. (3) They have different oxidation numbers. (4) They have different electronegativities. 10 Which formula represents a nonpolar molecule containing polar covalent bonds? (3) NH3 (1) H2O (2) CCl4 (4) H2 5 Which statement is true about oxidation and reduction in an electrochemical cell? (1) Both occur at the anode. (2) Both occur at the cathode. (3) Oxidation occurs at the anode and reduction occurs at the cathode. (4) Oxidation occurs at the cathode and reduction occurs at the anode. 11 The degree of polarity of a chemical bond in a molecule of a compound can be predicted by determining the difference in the (1) melting points of the elements in the compound (2) densities of the elements in the compound (3) electronegativities of the bonded atoms in a molecule of the compound (4) atomic masses of the bonded atoms in a molecule of the compound P.S./Chem.–Aug. ’06 [2] 18 The data table below gives the temperature and pressure of four different gas samples, each in a 2-liter container. 12 Which statement best describes the shape and volume of an aluminum cylinder at STP? (1) It has a definite shape and a definite volume. (2) It has a definite shape and no definite volume. (3) It has no definite shape and a definite volume. (4) It has no definite shape and no definite volume. Temperature and Pressure of Gas Samples 13 Which two substances can not be broken down by chemical change? (1) C and CuO (3) CO2 and CuO (2) C and Cu (4) CO2 and Cu Temperature (K) Pressure (atm) He 300. 1.20 Ne 300. 1.00 CO2 200. 1.20 CH4 300. 1.00 Which two gas samples contain the same total number of particles? 14 Which compound is insoluble in water? (3) KClO3 (1) BaSO4 (2) CaCrO4 (4) Na2S (1) CH4 and CO2 (2) CH4 and Ne 15 A sample of a gas is contained in a closed rigid cylinder. According to kinetic molecular theory, what occurs when the gas inside the cylinder is heated? (1) The number of gas molecules increases. (2) The number of collisions between gas molecules per unit time decreases. (3) The average velocity of the gas molecules increases. (4) The volume of the gas decreases. (3) He and CO2 (4) He and Ne 19 A chemical reaction is at equilibrium. Compared to the rate of the forward reaction, the rate of the reverse reaction is (1) faster and more reactant is produced (2) faster and more product is produced (3) the same and the reaction has stopped (4) the same and the reaction continues in both directions 20 Which organic compound is a saturated hydrocarbon? (1) ethyne (3) ethanol (2) ethene (4) ethane 16 Which statement best describes how a catalyst increases the rate of a reaction? (1) The catalyst provides an alternate reaction pathway with a higher activation energy. (2) The catalyst provides an alternate reaction pathway with a lower activation energy. (3) The catalyst provides the same reaction pathway with a higher activation energy. (4) The catalyst provides the same reaction pathway with a lower activation energy. 21 A substance is classified as an electrolyte because (1) it has a high melting point (2) it contains covalent bonds (3) its aqueous solution conducts an electric current (4) its aqueous solution has a pH value of 7 17 The compounds 2-butanol and 2-butene both contain (1) double bonds, only (3) carbon atoms (2) single bonds, only (4) oxygen atoms P.S./Chem.–Aug. ’06 Gas Sample 22 Half-reactions can be written to represent all (1) double-replacement reactions (2) neutralization reactions (3) fission and fusion reactions (4) oxidation and reduction reactions [3] [OVER] 23 Given the structural formulas: Formula B Formula A H H H C C H H H OH H C H Formula C H O C H H H H O H C C C H Formula D H H H H OH H C C C H H H H Which two formulas represent compounds that are isomers of each other? (1) A and B (3) B and D (2) A and C (4) C and D 27 Which equation represents a neutralization reaction? (1) 4Fe(s) + 3O2(g) → 2Fe2O3(s) (2) 2H2(g) + O2(g) → 2H2O(ᐉ) (3) HNO3(aq) + KOH(aq) → KNO3(aq) + H2O(ᐉ) (4) AgNO3(aq) + KCl(aq) → KNO3(aq) + AgCl(s) 24 Given the balanced equation representing a redox reaction: 2Al + 3Cu2+ → 2Al3+ + 3Cu Which statement is true about this reaction? (1) Each Al loses 2e– and each Cu2+ gains 3e–. (2) Each Al loses 3e– and each Cu2+ gains 2e–. (3) Each Al3+ gains 2e– and each Cu loses 3e–. (4) Each Al3+ gains 3e– and each Cu loses 2e–. 28 Which notation of a radioisotope is correctly paired with the notation of its emission particle? (3) 16N and 11p (1) 37Ca and 42He 25 Which conversion of energy always occurs in a voltaic cell? (1) light energy to chemical energy (2) electrical energy to chemical energy (3) chemical energy to light energy (4) chemical energy to electrical energy (2) and +10 e (4) 3H and –10e 29 Atoms of one element are converted to atoms of another element through (1) fermentation (3) polymerization (2) oxidation (4) transmutation 26 The compound NaOH(s) dissolves in water to yield (1) hydroxide ions as the only negative ions (2) hydroxide ions as the only positive ions (3) hydronium ions as the only negative ions (4) hydronium ions as the only positive ions P.S./Chem.–Aug. ’06 235U 30 An atom of potassium-37 and an atom of potassium-42 differ in their total number of (1) electrons (3) protons (2) neutrons (4) positrons [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 35 Which list of elements from Group 2 on the Periodic Table is arranged in order of increasing atomic radius? (1) Be, Mg, Ca (3) Ba, Ra, Sr (2) Ca, Mg, Be (4) Sr, Ra, Ba 31 What is the mass number of an atom that has six protons, six electrons, and eight neutrons? (1) 6 (3) 14 (2) 12 (4) 20 32 Which diagram represents the nucleus of an atom 27Al? of 13 14 n 27 n 27 p 13 p (1) 37 The percent composition by mass of magnesium in MgBr2 (gram-formula mass = 184 grams/mole) is equal to (3) 14 n 40 n 13 p 13 p (2) 36 Which half-reaction shows conservation of charge? (1) Cu + e– → Cu+ (3) Cu+ → Cu + e– (2) Cu2+ + 2e– → Cu (4) Cu2+ → Cu + 2e– (2) 1 2 g × 100 (3) 184 24 × 100 (2) 160. 184 × 100 (4) 184 160. × 100 CaCO3(s) + 2HCl(aq) → CaCl2(aq) + H2O(ᐉ) + CO2(g) (4) (3) 24 184 38 Given the balanced equation: What is the total number of moles of CO2 formed when 20. moles of HCl is completely consumed? 33 A student constructs a model for comparing the masses of subatomic particles. The student selects a small, metal sphere with a mass of 1 gram to represent an electron. A sphere with which mass would be most appropriate to represent a proton? (1) 1 g (1) 1 2000 (1) 5.0 mol (2) 10. mol (3) 20. mol (4) 40. mol 39 What amount of heat is required to completely melt a 29.95-gram sample of H2O(s) at 0°C? (1) 334 J (3) 1.00 × 103 J (2) 2260 J (4) 1.00 × 104 J g (4) 2000 g 34 Based on electronegativity values, which type of elements tends to have the greatest attraction for electrons in a bond? (1) metals (3) nonmetals (2) metalloids (4) noble gases P.S./Chem.–Aug. ’06 [5] [OVER] 44 Given the balanced equation representing a reaction: 40 Which particle diagram represents a mixture of element X and element Z, only? CH4(g) + 2O2(g) → 2H2O(g) + CO2(g) + heat Key = atom of X = atom of Z (1) Which statement is true about energy in this reaction? (1) The reaction is exothermic because it releases heat. (2) The reaction is exothermic because it absorbs heat. (3) The reaction is endothermic because it releases heat. (4) The reaction is endothermic because it absorbs heat. (3) 45 Given the reaction at equilibrium: N2(g) + 3H2(g) 2NH3(g) + 91.8 kJ What occurs when the concentration of H2(g) is increased? (2) (1) The rate of the forward reaction increases and the concentration of N2(g) decreases. (2) The rate of the forward reaction decreases and the concentration of N2(g) increases. (3) The rate of the forward reaction and the concentration of N2(g) both increase. (4) The rate of the forward reaction and the concentration of N2(g) both decrease. (4) 41 An unsaturated aqueous solution of NH3 is at 90.°C in 100. grams of water. According to Reference Table G, how many grams of NH3 could this unsaturated solution contain? (1) 5 g (3) 15 g (2) 10. g (4) 20. g 46 Given the potential energy diagram for a reaction: Potential Energy 42 How many total moles of KNO3 must be dissolved in water to make 1.5 liters of a 2.0 M solution? (1) 0.50 mol (3) 3.0 mol (2) 2.0 mol (4) 1.3 mol 43 Which statement explains why low temperature and high pressure are required to liquefy chlorine gas? (1) Chlorine molecules have weak covalent bonds. (2) Chlorine molecules have strong covalent bonds. (3) Chlorine molecules have weak intermolecular forces of attraction. (4) Chlorine molecules have strong intermolecular forces of attraction. P.S./Chem.–Aug. ’06 3 2 4 1 Reaction Coordinate Which interval on this diagram represents the difference between the potential energy of the products and the potential energy of the reactants? (1) 1 (2) 2 [6] (3) 3 (4) 4 49 Which list of the phases of H2O is arranged in order of increasing entropy? (1) ice, steam, and liquid water (2) ice, liquid water, and steam (3) steam, liquid water, and ice (4) steam, ice, and liquid water 47 Based on bond type, which compound has the highest melting point? (3) CaCl2 (1) CH3OH (2) C6H14 (4) CCl4 48 A 100.00-gram sample of naturally occurring boron contains 19.78 grams of boron-10 (atomic mass = 10.01 atomic mass units) and 80.22 grams of boron-11 (atomic mass = 11.01 atomic mass units). Which numerical setup can be used to determine the atomic mass of naturally occurring boron? (1) (0.1978)(10.01) + (0.8022)(11.01) 50 Solution A has a pH of 3 and solution Z has a pH of 6. How many times greater is the hydronium ion concentration in solution A than the hydronium ion concentration in solution Z? (1) 100 (3) 3 (2) 2 (4) 1000 (2) (0.8022)(10.01) + (0.1978)(11.01) (0.1978) (10.01) (3) (0.8022) (11.01) (4) (0.8022) (10.01) (0.1978) (11.01) P.S./Chem.–Aug. ’06 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 In the space in your answer booklet, draw a Lewis electron-dot diagram for a sulfur atom in the ground state. [1] 52 Explain, in terms of electron configuration, why selenium and sulfur have similar chemical properties. [1] Base your answers to questions 53 through 56 on the diagram below concerning the classification of matter. Classification of Matter Matter Mixtures Homogeneous Substances Elements X Z 53 What type of mixture is represented by X? [1] 54 What type of substance is represented by Z? [1] 55 Explain, in terms of particle arrangement, why NaCl(aq) is a homogeneous mixture. [1] 56 Given a mixture of sand and water, state one process that can be used to separate water from the sand. [1] P.S./Chem.–Aug. ’06 [8] Base your answers to questions 57 through 60 on the information below. An investigation was conducted to study the effect of the concentration of a reactant on the total time needed to complete a chemical reaction. Four trials of the same reaction were performed. In each trial the initial concentration of the reactant was different. The time needed for the chemical reaction to be completed was measured. The data for each of the four trials are shown in the table below. Reactant Concentration and Reaction Time Trial Initial Concentration (M) Reaction Time (s) 1 2 3 4 0.020 0.015 0.010 0.005 11 14 23 58 57 On the grid in your answer booklet, mark an appropriate scale on the axis labeled “Reaction Time (s).” An appropriate scale is one that allows a trend to be seen. [1] 58 On the same grid, plot the data from the data table. Circle and connect the points. [1] Example: 59 State the effect of the concentration of the reactant on the rate of the chemical reaction. [1] 60 In a different experiment involving the same reaction, it was found that an increase in temperature increased the rate of the reaction. Explain this result in terms of collision theory. [1] Base your answers to questions 61 through 63 on the equation below, which represents an organic compound reacting with bromine. H H H C H C C H + Br2 H H H H C C C H Br Br H H 61 What is the IUPAC name for the organic compound that reacts with Br2? [1] 62 What type of organic reaction is represented by this equation? [1] 63 What is the gram-formula mass of the product in this reaction? [1] P.S./Chem.–Aug. ’06 [9] [OVER] Base your answers to questions 64 and 65 on the information below. A U-238 atom decays to a Pb-206 atom through a series of steps. Each point on the graph below represents a nuclide and each arrow represents a nuclear decay mode. Uranium Disintegration Series 238 Mass Number 234 230 226 222 218 214 210 206 202 82 83 84 85 86 87 88 89 90 91 92 Pb Bi Po At Rn Fr Ra Ac Th Pa U Atomic Number and Chemical Symbol 64 Based on this graph, what particle is emitted during the nuclear decay of a Po-218 atom? [1] 65 Explain why the U-238 disintegration series ends with the nuclide Pb-206. [1] P.S./Chem.–Aug. ’06 [10] Part C Answer all questions in this part. Directions (66–85): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 66 and 67 on the information below. Some radioisotopes used as tracers make it possible for doctors to see the images of internal body parts and observe their functions. The table below lists information about three radioisotopes and the body part each radioisotope is used to study. Medical Uses of Some Radioisotopes Radioisotope Half-life Decay Mode Body Part 24Na 15 hours beta circulatory system 59Fe 44.5 days beta red blood cells 131I 8.1 days beta thyroid 66 Complete the equation in your answer booklet for the nuclear decay of the radioisotope used to study red blood cells. Include both the atomic number and the mass number for each missing particle. [1] 67 It could take up to 60. hours for a radioisotope to be delivered to the hospital from the laboratory where it is produced. What fraction of an original sample of 24Na remains unchanged after 60. hours? [1] Base your answers to questions 68 through 71 on the information below. A metal, M, was obtained from a compound in a rock sample. Experiments have determined that the element is a member of Group 2 on the Periodic Table of the Elements. 68 What is the phase of element M at STP? [1] 69 Explain, in terms of electrons, why element M is a good conductor of electricity. [1] 70 Explain why the radius of a positive ion of element M is smaller than the radius of an atom of element M. [1] 71 Using the symbol M for the element, write the chemical formula for the compound that forms when element M reacts with iodine. [1] P.S./Chem.–Aug. ’06 [11] [OVER] Base your answers to questions 72 through 75 on the information below. The graph below shows a compound being cooled at a constant rate starting in the liquid phase at 75°C and ending at 15°C. Temperature Changes Over Time Temperature (°C) 90. 70. 50. 30. 10. 0 2 4 Time (min) 6 8 72 What is the freezing point of the compound, in degrees Celsius? [1] 73 State what is happening to the average kinetic energy of the particles of the sample between minute 2 and minute 6. [1] 74 A different experiment was conducted with another sample of the same compound starting in the solid phase. The sample was heated at a constant rate from 15°C to 75°C. On the graph in your answer booklet, draw the resulting heating curve. [1] 75 What kelvin temperature is equal to 15°C? [1] Base your answers to questions 76 and 77 on the information below. Using burets, a student titrated a sodium hydroxide solution of unknown concentration with a standard solution of 0.10 M hydrochloric acid. The data are recorded in the table below. Titration Data Solution HCI(aq) NaOH(aq) Initial Buret Reading (mL) 15.50 5.00 Final Buret Reading (mL) 25.00 8.80 76 Determine both the total volume of HCl(aq) and the total volume of NaOH(aq) used in the titration. [1] 77 In the space in your answer booklet, show a correct numerical setup for calculating the molarity of the sodium hydroxide solution. [1] P.S./Chem.–Aug. ’06 [12] Base your answers to questions 78 and 79 on the information below. Many esters have distinctive odors, which lead to their widespread use as artificial flavorings and fragrances. For example, methyl butanoate has an odor like pineapple and ethyl methanoate has an odor like raspberry. 78 In the space in your answer booklet, draw a structural formula for the ester that has an odor like pineapple. [1] 79 What is a chemical name for the alcohol that reacts with methanoic acid to produce the ester that has an odor like raspberry? [1] Base your answers to questions 80 and 81 on the information below. Three bottles of liquids labeled 1, 2, and 3 were found in a storeroom. One of the liquids is known to be drain cleaner. Drain cleaners commonly contain KOH or NaOH. The pH of each liquid at 25°C was determined with a pH meter. The table below shows the test results. pH Test Results Bottle pH of Liquid 1 3.8 2 7.0 3 12.8 80 Explain how the pH results in this table enable a student to correctly conclude that bottle 3 contains the drain cleaner. [1] 81 Explain, in terms of the pH values, why thymol blue is not a suitable indicator to distinguish between the contents of bottle 1 and bottle 2. [1] P.S./Chem.–Aug. ’06 [13] [OVER] Base your answers to questions 82 through 85 on the information below. A student places a 2.50-gram sample of magnesium metal in a bottle and fits the bottle with a 2-hole stopper as shown in the diagram. Hydrochloric acid is added to the bottle, causing a reaction. As the reaction proceeds, hydrogen gas travels through the tubing to an inverted bottle filled with water, displacing some of the water in the bottle. HCl(aq) (reactant) H2(g) Water H2(g) Water Mg(s) (reactant) 82 Balance the equation in your answer booklet for the reaction of magnesium and hydrochloric acid, using the smallest whole-number coefficients. [1] 83 Identify the type of chemical reaction that occurs when magnesium reacts with hydrochloric acid. [1] 84 In the space in your answer booklet, show a correct numerical setup for calculating the number of moles of magnesium used in the experiment. [1] 85 Based on Reference Table J, explain why Ag(s) will not react with HCl(aq) to generate H2(g). [1] P.S./Chem.–Aug. ’06 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, August 16, 2006 — 12:30 to 3:30 p.m., only ANSWER SHEET I Male I Female Grade Student .............................................. Sex: ........... Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, August 16, 2006 — 12:30 to 3:30 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only 51 51 52 52 For Raters Only 53 53 54 54 55 55 56 56 57 and 58 Reaction Time (s) Reaction Time Versus Initial Concentration 57 58 0.000 0.005 0.010 0.015 Initial Concentration (M) [2] 0.020 0.025 For Raters Only 59 59 60 60 61 61 62 62 63 g/mol 63 64 64 65 65 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 66 59Fe 26 → + 66 67 67 68 68 69 69 70 70 71 72 71 °C 72 73 73 [4] For Raters Only Temperature (°C) 74 74 Time (min) 75 K 76 mL HCl(aq) and 75 mL NaOH(aq) 76 77 77 78 78 79 79 [5] [OVER] For Raters Only 80 80 81 81 82 Mg(s) + HCl(aq) → MgCl2(aq) + 83 H2(g) 82 83 84 84 85 85 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 25, 2007 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 1 Which subatomic particles are located in the nucleus of a neon atom? (1) electrons and positrons (2) electrons and neutrons (3) protons and neutrons (4) protons and electrons 6 An atom of argon rarely bonds to an atom of another element because an argon atom has (1) 8 valence electrons (2) 2 electrons in the first shell (3) 3 electron shells (4) 22 neutrons 2 The total mass of the protons in an atom of gold-198 is approximately (1) 79 atomic mass units (2) 119 atomic mass units (3) 198 atomic mass units (4) 277 atomic mass units 7 The elements on the Periodic Table are arranged in order of increasing (1) boiling point (3) atomic number (2) electronegativity (4) atomic mass 8 Which element is classified as a nonmetal? (1) Be (3) Si (2) Al (4) Cl 3 In a calcium atom in the ground state, the electrons that possess the least amount of energy are located in the (1) first electron shell (2) second electron shell (3) third electron shell (4) fourth electron shell 9 Solid samples of the element phosphorus can be white, black, or red in color. The variations in color are due to different (1) atomic masses (2) molecular structures (3) ionization energies (4) nuclear charges 4 Which group of atomic models is listed in historical order from the earliest to the most recent? (1) hard-sphere model, wave-mechanical model, electron-shell model (2) hard-sphere model, electron-shell model, wave-mechanical model (3) electron-shell model, wave-mechanical model, hard-sphere model (4) electron-shell model, hard-sphere model, wave-mechanical model 10 Given the balanced equation representing the reaction between propane and oxygen: C3H8 + 5O2 → 3CO2 + 4H2O According to this equation, which ratio of oxygen to propane is correct? 5 Which isotopic notation represents an atom of carbon-14? (1) 68 C (3) 146 C (2) 8C 6 P.S./Chem.–Jan. ’07 (4) 14 C 6 [2] (1) 5 grams O2 1 gram C3H8 (3) 10 grams O2 11 grams C3H8 (2) 5 moles O2 1 mole C3H8 (4) 10 moles O2 11 moles C3H8 16 The balanced equation below represents a molecule of bromine separating into two bromine atoms. 11 Lithium and potassium have similar chemical properties because the atoms of both elements have the same (1) mass number (2) atomic number (3) number of electron shells (4) number of valence electrons Br2 → Br + Br What occurs during this change? (1) Energy is absorbed and a bond is formed. (2) Energy is absorbed and a bond is broken. (3) Energy is released and a bond is formed. (4) Energy is released and a bond is broken. 12 Which two substances are covalent compounds? (1) C6H12O6(s) and KI(s) (2) C6H12O6(s) and HCl(g) (3) KI(s) and NaCl(s) (4) NaCl(s) and HCl(g) 17 Which substance can be decomposed by chemical means? (1) tungsten (3) krypton (2) antimony (4) methane 13 Which substance, when dissolved in water, forms a solution that conducts an electric current? (1) C2H5OH (3) C12H22O11 (2) C6H12O6 (4) CH3COOH 18 Bronze contains 90 to 95 percent copper and 5 to 10 percent tin. Because these percentages can vary, bronze is classified as (1) a compound (3) a mixture (2) an element (4) a substance 14 Given the diagram representing a reaction: 1n 0 235 92 U 137 52 Te 97 40 Zr 19 Compared to a 2.0 M aqueous solution of NaCl at 1 atmosphere, a 3.0 M aqueous solution of NaCl at 1 atmosphere has a (1) lower boiling point and a higher freezing point (2) lower boiling point and a lower freezing point (3) higher boiling point and a higher freezing point (4) higher boiling point and a lower freezing point 1n 0 1n 0 Which phrase best describes this type of reaction and the overall energy change that occurs? (1) nuclear, and energy is released (2) nuclear, and energy is absorbed (3) chemical, and energy is released (4) chemical, and energy is absorbed 20 In which reaction are electrons transferred from one reactant to another reactant? (1) 2Ca(s) + O2(g) → 2CaO(s) (2) AgNO3(aq) + KCl(aq) → AgCl(s) + KNO3(aq) (3) HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(ᐉ) (4) H3O+(aq) + OH–(aq) → 2H2O(ᐉ) 15 Compared to a phosphorus atom, a P3– ion has (1) more electrons and a larger radius (2) more electrons and a smaller radius (3) fewer electrons and a larger radius (4) fewer electrons and a smaller radius P.S./Chem.–Jan. ’07 [3] [OVER] 25 Two substances have different physical and chemical properties. Both substances have molecules that contain two carbon atoms, one oxygen atom, and six hydrogen atoms. These two substances must be (1) isomers of each other (2) isotopes of each other (3) the same compound (4) the same hydrocarbon 21 Which statement must be true for any chemical reaction at equilibrium? (1) The concentration of the products is greater than the concentration of the reactants. (2) The concentration of the products is less than the concentration of the reactants. (3) The concentration of the products and the concentration of the reactants are equal. (4) The concentration of the products and the concentration of the reactants are constant. 26 Given the balanced equation representing a reaction: 22 Given the structural formula: H H H H CH3CH2CH3 + Br2 → CH3CH2CH2Br + HBr O H C C C C C OH H H This organic reaction is best classified as (1) an addition reaction (2) an esterification reaction (3) a polymerization reaction (4) a substitution reaction H H What is the IUPAC name of this compound? (1) pentanal (3) methyl pentanoate (2) pentanol (4) pentanoic acid 27 In terms of energy and entropy, systems in nature tend to undergo changes toward (1) higher energy and higher entropy (2) higher energy and lower entropy (3) lower energy and higher entropy (4) lower energy and lower entropy 23 Which structural formula represents an unsaturated hydrocarbon? H H H C C H H H H H C H H (1) H H C OH (2) H O H C H (4) 29 Which compound has hydrogen bonding between its molecules? (1) CH4 (3) KH (2) CaH2 (4) NH3 24 Which group of nuclear emissions is listed in order of increasing charge? (1) alpha particle, beta particle, gamma radiation (2) gamma radiation, alpha particle, beta particle (3) positron, alpha particle, neutron (4) neutron, positron, alpha particle P.S./Chem.–Jan. ’07 C What is the total number of electrons shared in the bond between the two carbon atoms? (1) 6 (3) 3 (2) 2 (4) 4 H C H 28 Given the structural formula: (3) O C C 30 Which ion is the only negative ion produced by an Arrhenius base in water? (3) OH– (1) NO3– (2) Cl– (4) H– [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 36 Given the balanced equation representing a reaction: 31 When the elements in Group 1 are considered in order from top to bottom, each successive element at standard pressure has (1) a higher melting point and a higher boiling point (2) a higher melting point and a lower boiling point (3) a lower melting point and a higher boiling point (4) a lower melting point and a lower boiling point 4NH3 + 5O2 → 4NO + 6H2O What is the minimum O2 that are needed to 16 moles of NH3? (1) 16 mol (2) 20. mol (3) 64 mol (4) 80. mol 37 Which Lewis electron-dot diagram correctly represents a hydroxide ion? 32 Which isotopic notation identifies a metalloid that is matched with the corresponding number of protons in each of its atoms? (1) 24Mg and 12 protons (2) 28Si and 14 protons (3) 75As and 75 protons (4) 80Br and 80 protons – – OH O H (1) (3) – OH (2) 33 At STP, which list of elements contains a solid, a liquid, and a gas? (1) Hf, Hg, He (2) Cr, Cl2, C number of moles of completely react with – O H (4) 38 A 10.0-gram sample of which element has the smallest volume at STP? (1) aluminum (3) titanium (2) magnesium (4) zinc (3) Ba, Br2, B (4) Se, Sn, Sr 34 Element X reacts with iron to form two different compounds with the formulas FeX and Fe2X3. To which group on the Periodic Table does element X belong? (1) Group 8 (3) Group 13 (2) Group 2 (4) Group 16 39 At which temperature would atoms of a He(g) sample have the greatest average kinetic energy? (1) 25°C (3) 273 K (2) 37°C (4) 298 K 35 The molar mass of Ba(OH)2 is (1) 154.3 g (3) 171.3 g (2) 155.3 g (4) 308.6 g P.S./Chem.–Jan. ’07 [5] [OVER] 40 A student prepares four aqueous solutions, each with a different solute. The mass of each dissolved solute is shown in the table below. Mass of Dissolved Solute for Four Aqueous Solutions Solution Number Solute Mass of Dissolved Solute (per 100. g of H2O at 20.°C) 1 Kl 120. g 2 NaNO3 88 g 3 KCl 25 g 4 KClO3 5g Which solution is saturated? (1) 1 (2) 2 (3) 3 (4) 4 44 Given the system at equilibrium: 41 At room temperature, a mixture of sand and water can be separated by (1) ionization (3) filtration (2) combustion (4) sublimation 2POCl3(g) + energy Which changes occur when O2(g) is added to this system? (1) The equilibrium shifts to the right and the concentration of PCl3(g) increases. (2) The equilibrium shifts to the right and the concentration of PCl3(g) decreases. (3) The equilibrium shifts to the left and the concentration of PCl3(g) increases. (4) The equilibrium shifts to the left and the concentration of PCl3(g) decreases. 42 Given the balanced equation representing a reaction at 101.3 kPa and 298 K: N2(g) + 3H2(g) → 2NH3(g) + 91.8 kJ Which statement is true about this reaction? (1) It is exothermic and ΔH equals –91.8 kJ. (2) It is exothermic and ΔH equals +91.8 kJ. (3) It is endothermic and ΔH equals –91.8 kJ. (4) It is endothermic and ΔH equals +91.8 kJ. 45 What is the oxidation number of chromium in the chromate ion, CrO42–? (1) +6 (3) +3 (2) +2 (4) +8 43 Which balanced equation represents a phase equilibrium? (1) H2(g) + I2(g) 2HI(g) (2) 2NO2(g) N2O4(g) (3) Cl2(g) Cl2(ᐉ) (4) 3O2(g) 2O3(g) P.S./Chem.–Jan. ’07 2PCl3(g) + O2(g) [6] 46 Given the balanced equation representing a reaction: 49 If 1 8 of an original sample of krypton-74 remains unchanged after 34.5 minutes, what is the half-life of krypton-74? (1) 11.5 min (3) 34.5 min (2) 23.0 min (4) 46.0 min H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(ᐉ) Which type of reaction is represented by this equation? (1) decomposition (3) single replacement (2) neutralization (4) synthesis 50 Given the nuclear equation: 253 99Es 47 In which 0.01 M solution is phenolphthalein pink? (1) CH3OH(aq) (3) CH3COOH(aq) (2) Ca(OH)2(aq) (4) HNO3(aq) + X → 10 n + 256 101Md Which particle is represented by X? (3) 10 n (1) 42 He (2) –10 e (4) +10 e 48 As the pH of a solution is changed from 3 to 6, the concentration of hydronium ions (1) increases by a factor of 3 (2) increases by a factor of 1000 (3) decreases by a factor of 3 (4) decreases by a factor of 1000 P.S./Chem.–Jan. ’07 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–66): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 Naturally occurring boron is composed of two isotopes. The percent abundance and the mass of each isotope are listed below. • 19.9% of the boron atoms have a mass of 10.013 atomic mass units. • 80.1% of the boron atoms have a mass of 11.009 atomic mass units. In the space in your answer booklet, calculate the atomic mass of boron. Your response must include both a correct numerical setup and the calculated result. [2] Base your answers to questions 52 and 53 on the information below. During a laboratory activity, a student reacted a piece of zinc with 0.1 M HCl(aq). 52 Complete the equation in your answer booklet by writing the formula of the missing product. [1] 53 Based on Reference Table J, identify one metal that does not react spontaneously with HCl(aq). [1] 54 A hydrated compound contains water molecules within its crystal structure. The percent composition by mass of water in the hydrated compound CaSO4•2H2O has an accepted value of 20.9%. A student did an experiment and determined that the percent composition by mass of water in CaSO4•2H2O was 21.4%. In the space in your answer booklet, calculate the percent error of the student’s experimental result. Your response must include both a correct numerical setup and the calculated result. [2] P.S./Chem.–Jan. ’07 [8] Base your answers to questions 55 through 57 on the information below. The particle diagrams below represent the reaction between two nonmetals, A2 and Q2. Key = Atom of element A = Atom of element Q Reactants Product 55 Using the symbols A and Q, write the chemical formula of the product. [1] 56 Identify the type of chemical bond between an atom of element A and an atom of element Q. [1] 57 Compare the total mass of the reactants to the total mass of the product. [1] 58 A potential energy diagram for a chemical reaction is shown in your answer booklet. On this diagram, draw a curve to show how the potential energy diagram will change when a catalyst is added to the reaction. [1] 59 Explain, in terms of collision theory, why an increase in temperature increases the rate of a chemical reaction. [1] 60 An aqueous solution contains 300. parts per million of KOH. Determine the number of grams of KOH present in 1000. grams of this solution. [1] P.S./Chem.–Jan. ’07 [9] [OVER] Base your answers to questions 61 through 63 on the diagram below. The diagram shows a voltaic cell with copper and aluminum electrodes immediately after the external circuit is completed. Voltaic Cell V Voltmeter Wire Salt bridge Cu(s) electrode 2+ Al(s) electrode 3+ Cu (aq) Al (aq) Half-cell 1 Half-cell 2 61 Balance the redox equation in your answer booklet, using the smallest whole-number coefficients. [1] 62 As this voltaic cell operates, the mass of the Al(s) electrode decreases. Explain, in terms of particles, why this decrease in mass occurs. [1] 63 Explain the function of the salt bridge. [1] 64 Identify two indicators from Reference Table M that are yellow in solutions with a pH of 5.5. [1] 65 Explain, in terms of molecular structure or distribution of charge, why a molecule of methane is nonpolar. [1] 66 A liquid boils when the vapor pressure of the liquid equals the atmospheric pressure on the surface of the liquid. Using Reference Table H, determine the boiling point of water when the atmospheric pressure is 90. kPa. [1] P.S./Chem.–Jan. ’07 [10] Part C Answer all questions in this part. Directions (67–83): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 67 through 70 on the information below, which describes the proposed discovery of element 118. In 1999, a nuclear chemist and his team announced they had discovered a new element by crashing krypton atoms into lead. The new element, number 118, was assigned the name ununoctium and the symbol Uuo. One possible isotope of ununoctium could have been Uuo-291. However, the discovery of Uuo was not confirmed because other scientists could not reproduce the experimental results published by the nuclear chemist and his team. In 2006, another team of scientists claimed that they produced Uuo. This claim has yet to be confirmed. Adapted from Discover January 2002 67 Based on atomic number, in which group on the Periodic Table would element 118 be placed? [1] 68 What would be the total number of neutrons present in a theoretical atom of Uuo-291? [1] 69 What would be the total number of electrons present in a theoretical atom of Uuo-291? [1] 70 Explain why being able to reproduce scientific results is an important component of scientific research. [1] P.S./Chem.–Jan. ’07 [11] [OVER] Base your answers to questions 71 through 74 on the information below. Have you ever seen an insect called a water strider “skating” across the surface of a calm pond? Have you ever “floated” a sewing needle on the water in a glass? If you have, then you’ve observed one of water’s many amazing properties. Water’s surface tension keeps the water strider and the sewing needle from sinking into the water. Simply stated, the surface tension is due to the forces that hold the water molecules together. Without these intermolecular forces, the water strider and the sewing needle would sink below the surface of the water. The surface tension of water at various temperatures is given in the data table below. Surface Tension at Different Water Temperatures Water Temperature (°C) Surface Tension (mN/m) 10. 74.2 25 72.0 50. 67.9 75 63.6 100. 58.9 71 On the grid in your answer booklet, plot the data from the data table. Circle and connect the five points. [1] Example: 72 According to your graph, what is the surface tension of water at 60.°C? [1] 73 State the relationship between the surface tension and the temperature of water. [1] 74 The surface tension of liquid tetrachloromethane, CCl4, at 25°C is 26.3 millinewtons/meter (mN/m). Compare the intermolecular forces between molecules of CCl4 to the intermolecular forces between molecules of water, H2O, at 25°C. [1] P.S./Chem.–Jan. ’07 [12] Base your answers to questions 75 through 77 on the information below. A rigid cylinder is fitted with a movable piston. The cylinder contains a sample of helium gas, He(g), which has an initial volume of 125.0 milliliters and an initial pressure of 1.0 atmosphere, as shown below. The temperature of the helium gas sample is 20.0°C. Handle Movable piston 1.0 150.0 mL 125.0 mL 2.0 0 100.0 mL 3.0 Pressure gauge ATM 75.0 mL Rigid cylinder 50.0 mL 25.0 mL 75 Express the initial volume of the helium gas sample, in liters. [1] 76 The piston is pushed further into the cylinder. In the space in your answer booklet, show a correct numerical setup for calculating the volume of the helium gas that is anticipated when the reading on the pressure gauge is 1.5 atmospheres. The temperature of the helium gas remains constant. [1] 77 Helium gas is removed from the cylinder and a sample of nitrogen gas, N2(g), is added to the cylinder. The nitrogen gas has a volume of 125.0 milliliters and a pressure of 1.0 atmosphere at 20.0°C. Compare the number of particles in this nitrogen gas sample to the number of particles in the original helium gas sample. [1] P.S./Chem.–Jan. ’07 [13] [OVER] Base your answers to questions 78 through 81 on the information below. In preparing to titrate an acid with a base, a student puts on goggles and an apron. The student uses burets to dispense and measure the acid and the base in the titration. In each of two trials, a 0.500 M NaOH(aq) solution is added to a flask containing a volume of HCl(aq) solution of unknown concentration. Phenolphthalein is the indicator used in the titration. The calculated volumes used for the two trials are recorded in the table below. Volumes of Base and Acid Used in Titration Trials Solution (aq) NaOH HCl Trial 1 Trial 2 Molarity (M) Volume Used (mL) Volume Used (mL) 0.500 17.03 16.87 ? 10.22 10.12 78 Write a chemical name for the acid used in the titration. [1] 79 Using the volumes from trial 1, determine the molarity of the HCl(aq) solution. [1] 80 Based on the information given in the table, how many significant figures should be shown in the calculated molarity of the HCl(aq) solution used in trial 2? [1] 81 Identify one additional safety precaution the student should have taken before performing the titration. [1] P.S./Chem.–Jan. ’07 [14] Base your answers to questions 82 and 83 on the information below. A gasoline engine burns gasoline in the presence of excess oxygen to form carbon dioxide and water. The main components of gasoline are isomers of octane. A structural formula of octane is shown below. H H H H H H H H H C C C C C C C C H H H H H H H H H One isomer of octane is 2,2,4-trimethylpentane. 82 In the space in your answer booklet, draw a structural formula for 2,2,4-trimethylpentane. [1] 83 Explain, in terms of the arrangement of particles, why the entropy of gasoline vapor is greater than the entropy of liquid gasoline. [1] P.S./Chem.–Jan. ’07 [15] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Thursday, January 25, 2007 — 1:15 to 4:15 p.m., only ANSWER SHEET I Male I Female Grade Student .............................................. Sex: ........... Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 25, 2007 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 18 C 17 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only 51 51 atomic mass units 52 Zn(s) + 2HCl(aq)→ 53 (aq) + H2(g) 52 53 For Raters Only 54 54 % 55 55 56 56 57 57 [2] For Raters Only Potential Energy 58 58 Reaction Coordinate 59 59 60 61 g Cu2+(aq) + 60 Al(s) → Cu(s) + Al3+(aq) 61 62 62 63 63 [3] [OVER] For Raters Only 64 Indicator 1: 64 Indicator 2: 65 65 66 66 °C Total Score for Part B–2 Part C 67 67 68 68 69 69 70 70 [4] For Raters Only 71 Surface Tension Versus Water Temperature Surface Tension (mN/m) 75.0 70.0 71 65.0 60.0 55.0 0 20. 40. 60. 80. 100. Water Temperature (°C) 72 72 mN/m 73 73 74 74 [5] [OVER] For Raters Only 75 L 75 76 76 77 77 78 78 79 M 79 80 80 81 81 [6] For Raters Only 82 82 83 83 Total Score for Part C [7] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 20, 2007 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 Which element is most chemically similar to chlorine? (1) Ar (3) Fr (2) F (4) S 1 According to the wave-mechanical model of the atom, electrons in an atom (1) travel in defined circles (2) are most likely found in an excited state (3) have a positive charge (4) are located in orbitals outside the nucleus 7 Which substance can be decomposed by chemical means? (1) ammonia (3) phosphorus (2) oxygen (4) silicon 2 What is the total charge of the nucleus of a carbon atom? (1) –6 (3) +6 (2) 0 (4) +12 8 When an atom loses one or more electrons, this atom becomes a (1) positive ion with a radius smaller than the radius of this atom (2) positive ion with a radius larger than the radius of this atom (3) negative ion with a radius smaller than the radius of this atom (4) negative ion with a radius larger than the radius of this atom 3 A sample composed only of atoms having the same atomic number is classified as (1) a compound (3) an element (2) a solution (4) an isomer 4 Which two particles each have a mass approximately equal to one atomic mass unit? (1) electron and neutron (2) electron and positron (3) proton and electron (4) proton and neutron 9 What is the name of the polyatomic ion in the compound Na2O2? (1) hydroxide (3) oxide (2) oxalate (4) peroxide 5 Which two characteristics are associated with metals? (1) low first ionization energy and low electronegativity (2) low first ionization energy and high electronegativity (3) high first ionization energy and low electronegativity (4) high first ionization energy and high electronegativity P.S./Chem.–June ’07 10 Given the balanced equation: I + I → I2 Which statement describes the process represented by this equation? (1) (2) (3) (4) [2] A bond is formed as energy is absorbed. A bond is formed and energy is released. A bond is broken as energy is absorbed. A bond is broken and energy is released. 17 For a given reaction, adding a catalyst increases the rate of the reaction by (1) providing an alternate reaction pathway that has a higher activation energy (2) providing an alternate reaction pathway that has a lower activation energy (3) using the same reaction pathway and increasing the activation energy (4) using the same reaction pathway and decreasing the activation energy 11 An oxygen molecule contains a double bond because the two atoms of oxygen share a total of (1) 1 electron (3) 3 electrons (2) 2 electrons (4) 4 electrons 12 Which term is defined as a measure of the average kinetic energy of the particles in a sample? (1) temperature (3) thermal energy (2) pressure (4) chemical energy 13 A 3.0 M HCl(aq) solution contains a total of (1) 3.0 grams of HCl per liter of water (2) 3.0 grams of HCl per mole of solution (3) 3.0 moles of HCl per liter of solution (4) 3.0 moles of HCl per mole of water 18 Which reaction releases the greatest amount of energy per 2 moles of product? (1) 2CO(g) + O2(g) → 2CO2(g) (2) 4Al(s) + 3O2(g) → 2Al2O3(s) (3) 2H2(g) + O2(g) → 2H2O(g) (4) N2(g) + 3H2(g) → 2NH3(g) 14 A dilute, aqueous potassium nitrate solution is best classified as a (1) homogeneous compound (2) homogeneous mixture (3) heterogeneous compound (4) heterogeneous mixture 19 What is the total number of carbon atoms in a molecule of ethanoic acid? (1) 1 (3) 3 (2) 2 (4) 4 15 Given the equation representing a phase change at equilibrium: C2H5OH(ᐍ) 20 Given the formulas for two compounds: C2H5OH(g) H Which statement is true? (1) The forward process proceeds faster than the reverse process. (2) The reverse process proceeds faster than the forward process. (3) The forward and reverse processes proceed at the same rate. (4) The forward and reverse processes both stop. H H H C C O C C H H H H H and H H H H H C C C C OH H H H H These compounds differ in (1) gram-formula mass (2) molecular formula (3) percent composition by mass (4) physical properties at STP 16 A 5.0-gram sample of zinc and a 50.-milliliter sample of hydrochloric acid are used in a chemical reaction. Which combination of these samples has the fastest reaction rate? (1) a zinc strip and 1.0 M HCl(aq) (2) a zinc strip and 3.0 M HCl(aq) (3) zinc powder and 1.0 M HCl(aq) (4) zinc powder and 3.0 M HCl(aq) P.S./Chem.–June ’07 H 21 A double carbon-carbon bond is found in a molecule of (1) pentane (3) pentyne (2) pentene (4) pentanol [3] [OVER] 26 According to one acid-base theory, a water molecule acts as an acid when the water molecule (1) accepts an H+ (3) donates an H+ – (2) accepts an OH (4) donates an OH– 22 Which changes occur when Pt2+ is reduced? (1) The Pt2+ gains electrons and its oxidation number increases. (2) The Pt2+ gains electrons and its oxidation number decreases. (3) The Pt2+ loses electrons and its oxidation number increases. (4) The Pt2+ loses electrons and its oxidation number decreases. 27 Which list of radioisotopes contains an alpha emitter, a beta emitter, and a positron emitter? (1) C-14, N-16, P-32 (2) Cs-137, Fr-220, Tc-99 (3) Kr-85, Ne-19, Rn-222 (4) Pu-239, Th-232, U-238 23 Which balanced equation represents an oxidation-reduction reaction? (1) BaCl2 + Na2SO4 → BaSO4 + 2NaCl (2) C + H2O → CO + H2 28 Which nuclear decay emission consists of energy, only? (1) alpha particle (3) gamma radiation (2) beta particle (4) positron (3) CaCO3 → CaO + CO2 (4) Mg(OH)2 + 2HNO3 → Mg(NO3)2 + 2H2O 24 Which energy conversion occurs during the operation of a voltaic cell? (1) Chemical energy is spontaneously converted to electrical energy. (2) Chemical energy is converted to electrical energy only when an external power source is provided. (3) Electrical energy is spontaneously converted to chemical energy. (4) Electrical energy is converted to chemical energy only when an external power source is provided. 29 Which balanced equation represents nuclear fusion? 142 91 1 (1) 01n + 235 92U → 56Ba + 36Kr + 30n (2) 4 → 222 86Rn + 2He (3) 63Li + 10 n → 31H + 42He (4) 21H + 31H → 42He + 01n 30 The energy released by a nuclear reaction results primarily from the (1) breaking of bonds between atoms (2) formation of bonds between atoms (3) conversion of mass into energy (4) conversion of energy into mass 25 An Arrhenius base yields which ion as the only negative ion in an aqueous solution? (1) hydride ion (3) hydronium ion (2) hydrogen ion (4) hydroxide ion P.S./Chem.–June ’07 226 88Ra [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 Which electron configuration could represent a strontium atom in an excited state? (1) 2–8–18–7–1 (3) 2–8–18–8–1 (2) 2–8–18–7–3 (4) 2–8–18–8–2 37 Compared to an electron in the first electron shell of an atom, an electron in the third shell of the same atom has (1) less mass (3) more mass (2) less energy (4) more energy 32 Which grouping of circles, when considered in order from the top to the bottom, best represents the relative size of the atoms of Li, Na, K, and Rb, respectively? 38 Which pair consists of a molecular formula and its corresponding empirical formula? (1) C2H2 and CH3CH3 (3) P4O10 and P2O5 (2) C6H6 and C2H2 (4) SO2 and SO3 39 Which particle diagram represents a sample of one compound, only? Key (1) (2) (3) (4) = atom of one element = atom of a different element 33 What is the total number of neutrons in an atom of 57 26Fe? (1) 26 (2) 31 (3) 57 (4) 83 34 At STP, which element is brittle and not a conductor of electricity? (1) S (3) Na (2) K (4) Ar (1) (3) (2) (4) 35 What is the total number of electrons in a Mg2+ ion? (1) 10 (3) 14 (2) 12 (4) 24 36 Which formula represents lead(II) chromate? (3) Pb2CrO4 (1) PbCrO4 (2) Pb(CrO4)2 P.S./Chem.–June ’07 (4) Pb2(CrO4)3 [5] [OVER] 40 An atom in the ground state contains a total of 5 electrons, 5 protons, and 5 neutrons. Which Lewis electron-dot diagram represents this atom? X X X X (1) (2) (3) (4) 46 The organic compound represented by the condensed structural formula CH3CH2CH2CHO is classified as an (1) alcohol (3) ester (2) aldehyde (4) ether 47 Given the balanced ionic equation representing a reaction: 2Al3+(aq) + 3Mg(s) → 3Mg2+(aq) + 2Al(s) 41 At STP, fluorine is a gas and bromine is a liquid because, compared to fluorine, bromine has (1) stronger covalent bonds (2) stronger intermolecular forces (3) weaker covalent bonds (4) weaker intermolecular forces In this reaction, electrons are transferred from (4) Mg2+ to Al (3) KHCO3 and KHSO4 (4) NaSCN and Na2S2O3 49 Information related to a titration experiment is given in the balanced equation and table below. H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(ᐍ) Titration Experiment Results volume of H2SO4(aq) used 44 Given the equation representing a reaction at equilibrium: concentration of H2SO4(aq) 2NH3(g) + energy Which change causes the equilibrium to shift to the right? 12.0 mL ? volume of KOH(aq) used 36.0 mL concentration of KOH(aq) 0.16 M Based on the equation and the titration results, what is the concentration of the H2SO4(aq)? (1) 0.12 M (3) 0.24 M (2) 0.16 M (4) 0.96 M decreasing the concentration of H2(g) decreasing the pressure increasing the concentration of N2(g) increasing the temperature 50 Which radioisotope is used in medicine to treat thyroid disorders? (1) cobalt-60 (3) phosphorus-32 (2) iodine-131 (4) uranium-238 45 Which compound is an unsaturated hydrocarbon? (1) hexanal (3) hexanoic acid (2) hexane (4) hexyne P.S./Chem.–June ’07 (2) Al3+ to Mg (2) HC2H3O2 and H3PO4 43 At which Celsius temperature does lead change from a solid to a liquid? (1) 874°C (3) 328°C (2) 601°C (4) 0°C (1) (2) (3) (4) (3) Mg to Al3+ 48 Which two formulas represent Arrhenius acids? (1) CH3COOH and CH3CH2OH 42 The boiling point of a liquid is the temperature at which the vapor pressure of the liquid is equal to the pressure on the surface of the liquid. What is the boiling point of propanone if the pressure on its surface is 48 kilopascals? (1) 25°C (3) 35°C (2) 30.°C (4) 40.°C N2(g) + 3H2(g) (1) Al to Mg2+ [6] Part B–2 Answer all questions in this part. Directions (51–63): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 through 53 on the information below. A gas sample is held at constant temperature in a closed system. The volume of the gas is changed, which causes the pressure of the gas to change. Volume and pressure data are shown in the table below. Volume and Pressure of a Gas Sample Volume (mL) Pressure (atm) 1200 0.5 600 1.0 300 2.0 150 4.0 100 6.0 51 On the grid in your answer booklet, mark an appropriate scale on the axis labeled “Volume (mL).” [1] 52 On the same grid, plot the data from the table. Circle and connect the points. [1] Example: 53 Based on your graph, what is the pressure of the gas when the volume of the gas is 200. milliliters? [1] 54 Explain, in terms of collision theory, why the rate of a chemical reaction increases with an increase in temperature. [1] 55 Determine the percent composition by mass of oxygen in the compound C6H12O6. [1] P.S./Chem.–June ’07 [7] [OVER] Base your answers to questions 56 through 58 on the information below. A 5.00-gram sample of liquid ammonia is originally at 210. K. The diagram of the partial heating curve below represents the vaporization of the sample of ammonia at standard pressure due to the addition of heat. The heat is not added at a constant rate. Temperature (K) Partial Heating Curve for Ammonia 270. 240. 210. A B C D Time Some physical constants for ammonia are shown in the data table below. Some Physical Constants for Ammonia specific heat capacity of NH3(ᐉ) 4.71 J/g• K heat of fusion 332 J/g heat of vaporization 1370 J/g 56 In the space in your answer booklet, calculate the total heat absorbed by the 5.00-gram sample of ammonia during time interval AB. Your response must include both a correct numerical setup and the calculated result. [2] 57 Describe what is happening to both the potential energy and the average kinetic energy of the molecules in the ammonia sample during time interval BC. Your response must include both potential energy and average kinetic energy. [1] 58 Determine the total amount of heat required to vaporize this 5.00-gram sample of ammonia at its boiling point. [1] P.S./Chem.–June ’07 [8] Base your answers to questions 59 and 60 on the information below. The unbalanced equation below represents the decomposition of potassium chlorate. KClO3(s) → KCl(s) + O2(g) 59 Balance the equation in your answer booklet, using the smallest whole-number coefficients. [1] 60 Determine the oxidation number of chlorine in the reactant. [1] 61 Complete the nuclear equation in your answer booklet. Include the symbol, atomic number, and mass number for the missing particle. [1] 62 Explain, in terms of electronegativity, why a P–Cl bond in a molecule of PCl5 is more polar than a P–S bond in a molecule of P2S5. [1] 63 A 1.00-mole sample of neon gas occupies a volume of 24.4 liters at 298 K and 101.3 kilopascals. In the space in your answer booklet, calculate the density of this sample. Your response must include both a correct numerical setup and the calculated result. [2] P.S./Chem.–June ’07 [9] [OVER] Part C Answer all questions in this part. Directions (64–82): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 64 through 66 on the information below. Scientists who study aquatic ecosystems are often interested in the concentration of dissolved oxygen in water. Oxygen, O2, has a very low solubility in water, and therefore its solubility is usually expressed in units of milligrams per 1000. grams of water at 1.0 atmosphere. The graph below shows a solubility curve of oxygen in water. Solubility of Oxygen in Water Versus Temperature Mass of Dissolved O2 (mg) in 1000. g of Water 15.0 10.0 5.0 0 0 10. 20. 30. Temperature (°C) 64 A student determines that 8.2 milligrams of oxygen is dissolved in a 1000.-gram sample of water at 15°C and 1.0 atmosphere. In terms of saturation, what type of solution is this sample? [1] 65 Explain, in terms of molecular polarity, why oxygen gas has low solubility in water. Your response must include both oxygen and water. [1] 66 An aqueous solution has 0.0070 gram of oxygen dissolved in 1000. grams of water. In the space in your answer booklet, calculate the dissolved oxygen concentration of this solution in parts per million. Your response must include both a correct numerical setup and the calculated result. [2] P.S./Chem.–June ’07 [10] Base your answers to questions 67 and 68 on the information below. Sulfur dioxide, SO2, is one gas produced when fossil fuels are burned. When this gas reacts with water in the atmosphere, an acid is produced forming acid rain. The pH of the water in a lake changes when acid rain collects in the lake. Two samples of the same rainwater are tested using two indicators. Methyl orange is yellow in one sample of this rainwater. Litmus is red in the other sample of this rainwater. 67 Identify a possible pH value for the rainwater that was tested. [1] 68 Write the formula for one substance that can neutralize the lake water affected by acid rain. [1] Base your answers to questions 69 through 72 on the information below. Propane is a fuel that is sold in rigid, pressurized cylinders. Most of the propane in a cylinder is liquid, with gas in the space above the liquid level. When propane is released from the cylinder, the propane leaves the cylinder as a gas. Propane gas is used as a fuel by mixing it with oxygen in the air and igniting the mixture, as represented by the balanced equation below. C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(ᐍ) + 2219.2 kJ A small amount of methanethiol, which has a distinct odor, is added to the propane to help consumers detect a propane leak. In methanethiol, the odor is caused by the thiol functional group (–SH). Methanethiol, CH3SH, has a structure that is very similar to the structure of methanol. 69 In the box in your answer booklet, draw a particle diagram to represent propane in a pressurized cylinder using the key in your answer booklet. Your response must include at least six molecules of propane in the gas phase and at least six molecules of propane in the liquid phase. [1] 70 On the diagram in your answer booklet, draw a potential energy diagram for this reaction. [1] 71 Determine the total amount of energy released when 2.50 moles of propane is completely reacted with oxygen. [1] 72 In the space in your answer booklet, draw a structural formula for a molecule of methanethiol. [1] P.S./Chem.–June ’07 [11] [OVER] Base your answers to questions 73 through 76 on the information below. The table below lists physical and chemical properties of six elements at standard pressure that correspond to known elements on the Periodic Table. The elements are identified by the code letters, D, E, G, J, L, and Q. Properties of Six Elements at Standard Pressure Element D Density 0.00018 g/cm3 Melting point –272°C Boiling point –269°C Oxide formula (none) Element E Density 1.82 g/cm3 Melting point 44°C Boiling point 280°C Oxide formula E2O5 Element G Density 0.53 g/cm3 Melting point 181°C Boiling point 1347°C Oxide formula G2O Element J Density 0.0013 g/cm3 Melting point –210°C Boiling point –196°C Oxide formula J2O5 Element L Density 0.86 g/cm3 Melting point 64°C Boiling point 774°C Oxide formula L2O Element Q Density 0.97 g/cm3 Melting point 98°C Boiling point 883°C Oxide formula Q2O 73 What is the total number of elements in the “Properties of Six Elements at Standard Pressure” table that are solids at STP? [1] 74 An atom of element G is in the ground state. What is the total number of valence electrons in this atom? [1] 75 Letter Z corresponds to an element on the Periodic Table other than the six listed elements. Elements G, Q, L, and Z are in the same group on the Periodic Table, as shown in the diagram below. G Q L Z Based on the trend in the melting points for elements G, Q, and L listed in the “Properties of Six Elements at Standard Pressure” table, estimate the melting point of element Z, in degrees Celsius. [1] 76 Identify, by code letter, the element that is a noble gas in the “Properties of Six Elements at Standard Pressure” table. [1] P.S./Chem.–June ’07 [12] Base your answers to questions 77 through 79 on the information below. Ozone gas, O3, can be used to kill adult insects in storage bins for grain without damaging the grain. The ozone is produced from oxygen gas, O2, in portable ozone generators located near the storage bins. The concentrations of ozone used are so low that they do not cause any environmental damage. This use of ozone is safer and more environmentally friendly than a method that used bromomethane, CH3Br. However, bromomethane was more effective than ozone because CH3Br killed immature insects as well as adult insects. Adapted From: The Sunday Gazette (Schenectady, NY) 3/9/03 77 Determine the total number of moles of CH3Br in 19 grams of CH3Br (gram-formula mass = 95 grams/mol). [1] 78 Given the balanced equation for producing bromomethane: Br2 + CH4 → CH3Br + HBr Identify the type of organic reaction shown. [1] 79 Based on the information in the passage, state one advantage of using ozone instead of bromomethane for insect control in grain storage bins. [1] Base your answers to questions 80 through 82 on the information below. In living organisms, the ratio of the naturally occurring isotopes of carbon, C-12 to C-13 to C-14, is fairly consistent. When an organism such as a woolly mammoth died, it stopped taking in carbon, and the amount of C-14 present in the mammoth began to decrease. For example, one fossil of a woolly mammoth is found to have 321 of the amount of C-14 found in a living organism. 80 Identify the type of nuclear reaction that caused the amount of C-14 in the woolly mammoth to decrease after the organism died. [1] 81 Determine the total time that has elapsed since this woolly mammoth died. [1] 82 State, in terms of subatomic particles, how an atom of C-13 is different from an atom of C-12. [1] P.S./Chem.–June ’07 [13] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, June 20, 2007 — 1:15 to 4:15 p.m., only ANSWER SHEET I Male I Female Grade ........... Student .............................................. Sex: Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 20, 2007 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade. . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only 51–52 Pressure Versus Volume of a Gas Sample 6.0 Pressure (atm) 5.0 4.0 51 3.0 52 2.0 1.0 0 Volume (mL) 53 atm 53 For Raters Only 54 54 55 55 % 56 56 J 57 57 58 J 59 KClO3(s) → 58 KCl(s) + O2(g) 59 60 60 [2] For Raters Only 61 42K 19 → –10e + 61 62 62 63 63 g/L Total Score for Part B–2 [3] [OVER] For Raters Only Part C 64 64 65 65 66 66 ppm 67 67 68 68 [4] For Raters Only 69 Key = propane molecule 69 Potential Energy 70 70 Reaction Coordinate 71 kJ 71 72 72 [5] [OVER] For Raters Only 73 73 74 74 75 °C 75 76 76 77 77 mol 78 78 79 79 80 80 81 y 81 82 82 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, August 16, 2007 — 12:30 to 3:30 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 5 Which element has both metallic and nonmetallic properties? (1) Rb (3) Si (2) Rn (4) Sr 1 What was concluded about the structure of the atom as the result of the gold foil experiment? (1) A positively charged nucleus is surrounded by positively charged particles. (2) A positively charged nucleus is surrounded by mostly empty space. (3) A negatively charged nucleus is surrounded by positively charged particles. (4) A negatively charged nucleus is surrounded by mostly empty space. 6 The carbon atoms in graphite and the carbon atoms in diamond have different (1) atomic numbers (2) atomic masses (3) electronegativities (4) structural arrangements 2 An atom is electrically neutral because the (1) number of protons equals the number of electrons (2) number of protons equals the number of neutrons (3) ratio of the number of neutrons to the number of electrons is 1:1 (4) ratio of the number of neutrons to the number of protons is 2:1 7 Atoms of which element have the greatest tendency to gain electrons? (1) bromine (3) fluorine (2) chlorine (4) iodine 8 Which statement describes a chemical property of the element magnesium? (1) Magnesium is malleable. (2) Magnesium conducts electricity. (3) Magnesium reacts with an acid. (4) Magnesium has a high boiling point. 3 How do the energy and the most probable location of an electron in the third shell of an atom compare to the energy and the most probable location of an electron in the first shell of the same atom? (1) In the third shell, an electron has more energy and is closer to the nucleus. (2) In the third shell, an electron has more energy and is farther from the nucleus. (3) In the third shell, an electron has less energy and is closer to the nucleus. (4) In the third shell, an electron has less energy and is farther from the nucleus. 9 Matter that is composed of two or more different elements chemically combined in a fixed proportion is classified as (1) a compound (3) a mixture (2) an isotope (4) a solution 10 Given the balanced equation representing a reaction: 2CO(g) + O2(g) → 2CO2(g) 4 Which element is a solid at STP and a good conductor of electricity? (1) iodine (3) nickel (2) mercury (4) sulfur P.S./Chem.–Aug. ’07 What is the mole ratio of CO(g) to CO2(g) in this reaction? (1) 1:1 (3) 2:1 (2) 1:2 (4) 3:2 [2] 11 Given the balanced equation representing a reaction: 19 At STP, which sample contains the same number of molecules as 11.2 liters of CO2(g) at STP? (3) 11.2 L of N2(g) (1) 5.6 L of NO2(g) (4) 22.4 L of CO(g) (2) 7.5 L of H2(g) H+(aq) + OH–(aq) → H2O(ᐉ) + 55.8 kJ In this reaction there is conservation of (1) mass, only (2) mass and charge, only (3) mass and energy, only (4) mass, charge, and energy 20 A sample of gas is held at constant pressure. Increasing the kelvin temperature of this gas sample causes the average kinetic energy of its molecules to (1) decrease and the volume of the gas sample to decrease (2) decrease and the volume of the gas sample to increase (3) increase and the volume of the gas sample to decrease (4) increase and the volume of the gas sample to increase 12 Which polyatomic ion contains the greatest number of oxygen atoms? (1) acetate (3) hydroxide (2) carbonate (4) peroxide 13 Which formula represents an ionic compound? (3) CH3OH (1) H2 (4) NH4Cl (2) CH4 21 Given the balanced equation representing a reaction: 14 An ion of which element has a larger radius than an atom of the same element? (1) aluminum (3) magnesium (2) chlorine (4) sodium Cl2(g) → Cl(g) + Cl(g) What occurs during this change? (1) Energy is absorbed and a bond is broken. (2) Energy is absorbed and a bond is formed. (3) Energy is released and a bond is broken. (4) Energy is released and a bond is formed. 15 Which statement must be true when solution equilibrium occurs? (1) The solution is at STP. (2) The solution is supersaturated. (3) The concentration of the solution remains constant. (4) The masses of the dissolved solute and the undissolved solute are equal. 22 A molecule of butane and a molecule of 2-butene both have the same total number of (1) carbon atoms (3) single bonds (2) hydrogen atoms (4) double bonds 23 Which general formula represents the homologous series of hydrocarbons that includes the compound l-heptyne? (1) CnH2n–6 (3) CnH2n (2) CnH2n–2 (4) CnH2n+2 16 Which liquid has the highest vapor pressure at 75°C? (1) ethanoic acid (3) propanone (2) ethanol (4) water 17 What is the total number of different elements present in NH4NO3? (1) 7 (3) 3 (2) 9 (4) 4 24 Which two compounds are isomers of each other? (1) CH3CH2COOH and CH3COOCH2CH3 (2) CH3CH2CHO and CH3COCH3 (3) CH3CHBrCH3 and CH2BrCHBrCH3 (4) CH3CHOHCH3 and CH3CHOHCH2OH 18 Which sample of matter is a single substance? (1) air (3) hydrochloric acid (2) ammonia gas (4) salt water P.S./Chem.–Aug. ’07 [3] [OVER] 25 Which formula represents an unsaturated hydrocarbon? H H H C C H H H H (1) H (2) H C C H H Cl 28 What is the decay mode of 37K? (3) γ (1) β– (2) β+ (4) α (3) H H H H C C H H 27 Which compound is an Arrhenius acid? (3) NaOH (1) H2SO4 (2) KCl (4) NH3 29 Which nuclear emission has the greatest penetrating power? (1) alpha particle (3) gamma radiation (2) beta particle (4) positron H C C Cl (4) 30 What is the mass number of an alpha particle? (1) 1 (3) 0 (2) 2 (4) 4 26 Which formula represents a hydronium ion? (3) OH– (1) H3O+ (2) NH4+ (4) HCO3– P.S./Chem.–Aug. ’07 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 What is the net charge on an ion that has 9 protons, 11 neutrons, and 10 electrons? (1) 1+ (3) 1– (2) 2+ (4) 2– 36 At standard pressure, a certain compound has a low boiling point and is insoluble in water. At STP, this compound most likely exists as (1) ionic crystals (2) metallic crystals (3) nonpolar molecules (4) polar molecules 32 Which two particles make up most of the mass of a hydrogen-2 atom? (1) electron and neutron (2) electron and proton (3) proton and neutron (4) proton and positron 37 The table below shows mass and volume data for four samples of substances at 298 K and 1 atmosphere. Masses and Volumes of Four Samples 33 Which statement explains why sulfur is classified as a Group 16 element? (1) A sulfur atom has 6 valence electrons. (2) A sulfur atom has 16 neutrons. (3) Sulfur is a yellow solid at STP. (4) Sulfur reacts with most metals. Sample A 30. 60. B 40. 50. C 45. 90. D 90. 120. Which two samples could consist of the same substance? (1) A and B (3) B and C (2) A and C (4) C and D 34 How do the atomic radius and metallic properties of sodium compare to the atomic radius and metallic properties of phosphorus? (1) Sodium has a larger atomic radius and is more metallic. (2) Sodium has a larger atomic radius and is less metallic. (3) Sodium has a smaller atomic radius and is more metallic. (4) Sodium has a smaller atomic radius and is less metallic. 38 Which group on the Periodic Table of the Elements contains elements that react with oxygen to form compounds with the general formula X2O? (1) Group 1 (3) Group 14 (2) Group 2 (4) Group 18 35 A compound has a molar mass of 90. grams per mole and the empirical formula CH2O. What is the molecular formula of this compound? (3) C3H6O3 (1) CH2O (2) C2H4O2 (4) C4H8O4 P.S./Chem.–Aug. ’07 Mass (g) Volume (mL) 39 An unsaturated solution is formed when 80. grams of a salt is dissolved in 100. grams of water at 40.°C. This salt could be (1) KCl (3) NaCl (2) KNO3 (4) NaNO3 [5] [OVER] 44 Given the unbalanced ionic equation: 40 Which kelvin temperature is equal to 56°C? (1) –329 K (3) 217 K (2) –217 K (4) 329 K 3Mg + ____ Fe3+ → 3Mg2+ + ____ Fe When this equation is balanced, both Fe3+ and Fe have a coefficient of (1) 1, because a total of 6 electrons is transferred (2) 2, because a total of 6 electrons is transferred (3) 1, because a total of 3 electrons is transferred (4) 2, because a total of 3 electrons is transferred 41 Given the formula of a substance: H H C C H H H C C H 45 A student collects the materials and equipment below to construct a voltaic cell. What is the total number of shared electrons in a molecule of this substance? (1) 22 (3) 9 (2) 11 (4) 6 • • • • • • 42 Given the balanced equation representing the reaction occurring in a voltaic cell: Zn(s) + Pb2+(aq) → Zn2+(aq) + Pb(s) two 250-mL beakers wire and a switch one strip of magnesium one strip of copper 125 mL of 0.20 M Mg(NO3)2(aq) 125 mL of 0.20 M Cu(NO3)2(aq) Which additional item is required for the construction of the voltaic cell? (1) an anode (3) a cathode (2) a battery (4) a salt bridge In the completed external circuit, the electrons flow from (1) Pb(s) to Zn(s) (2) Pb2+(aq) to Zn2+(aq) (3) Zn(s) to Pb(s) (4) Zn2+(aq) to Pb2+(aq) 46 Given the balanced equation representing a reaction: Zn(s) + 2HCl(aq) → H2(g) + ZnCl2(aq) 43 Which balanced equation represents a redox reaction? Which set of reaction conditions produces H2(g) at the fastest rate? (1) a 1.0-g lump of Zn(s) in 50. mL of 0.5 M HCl(aq) at 20.°C (2) a 1.0-g lump of Zn(s) in 50. mL of 0.5 M HCl(aq) at 30.°C (3) 1.0 g of powdered Zn(s) in 50. mL of 1.0 M HCl(aq) at 20.°C (4) 1.0 g of powdered Zn(s) in 50. mL of 1.0 M HCl(aq) at 30.°C (1) CuCO3(s) → CuO(s) + CO2(g) (2) 2KClO3(s) → 2KCl(s) + 3O2(g) (3) AgNO3(aq) + KCl(aq) → AgCl(s) + KNO3(aq) (4) H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(ᐉ) P.S./Chem.–Aug. ’07 [6] 49 Which nuclear equation represents a natural transmutation? (1) 94Be + 11H → 63Li + 42He 47 The table below shows the color of the indicators methyl orange and litmus in two samples of the same solution. (2) Results of Acid-Base Indicator Tests Indicator Color Result from the Indicator Test methyl orange yellow litmus red (3) (4) 27 4 30 1 13Al + 2He → 15P + 0n 14 4 17 1 7N + 2He → 8O + 1H 235 231 4 92U → 90Th + 2He 50 A nuclear fission reaction and a nuclear fusion reaction are similar because both reactions (1) form heavy nuclides from light nuclides (2) form light nuclides from heavy nuclides (3) release a large amount of energy (4) absorb a large amount of energy Which pH value is consistent with the indicator results? (1) 1 (3) 3 (2) 5 (4) 10 48 What is the pH of a solution that has a hydronium ion concentration 100 times greater than a solution with a pH of 4? (1) 5 (3) 3 (2) 2 (4) 6 P.S./Chem.–Aug. ’07 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–66): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 What is the oxidation number of nitrogen in NO(g)? [1] 52 Write an electron configuration for an atom of aluminum-27 in an excited state. [1] 53 What color is bromcresol green after it is added to a sample of NaOH(aq)? [1] Base your answers to questions 54 through 56 on the information below. The accepted values for the atomic mass and percent natural abundance of each naturally occurring isotope of silicon are given in the data table below. Naturally Occurring Isotopes of Silicon Isotope Atomic Mass (atomic mass units) Percent Natural Abundance (%) Si-28 27.98 92.22 Si-29 28.98 4.69 Si-30 29.97 3.09 54 Determine the total number of neutrons in an atom of Si-29. [1] 55 In the space in your answer booklet, show a correct numerical setup for calculating the atomic mass of Si. [1] 56 A scientist calculated the percent natural abundance of Si-30 in a sample to be 3.29%. Determine the percent error for this value. [1] P.S./Chem.–Aug. ’07 [8] Base your answers to questions 57 through 60 on the information below. The temperature of a sample of a substance is increased from 20.°C to 160.°C as the sample absorbs heat at a constant rate of 15 kilojoules per minute at standard pressure. The graph below represents the relationship between temperature and time as the sample is heated. Temperature (°C) Temperature Versus Time 180. 160. 140. 120. 100. 80. 60. 40. 20. 0 2.0 4.0 6.0 8.0 10.0 12.0 Time (min) 57 What is the boiling point of this sample? [1] 58 In your answer booklet, use the key to draw at least nine particles in the box, showing the correct particle arrangement of this sample during the first minute of heating. [1] 59 What is the total time this sample is in the liquid phase, only? [1] 60 Determine the total amount of heat required to completely melt this sample at its melting point. [1] Base your answers to questions 61 through 63 on the reaction represented by the balanced equation below. 2H2(g) + O2(g) → 2H2O(ᐉ) + 571.6 kJ 61 Identify the information in this equation that indicates the reaction is exothermic. [1] 62 On the axes in your answer booklet, draw a potential energy diagram for the reaction represented by this equation. [1] 63 Explain why the entropy of the system decreases as the reaction proceeds. [1] P.S./Chem.–Aug. ’07 [9] [OVER] Base your answers to questions 64 through 66 on the information below. The incomplete equation below represents an esterification reaction. The alcohol reactant is represented by X. H O H C C OH + H X catalyst H H O H H H C C O C C C H + H2O H H H H 64 On the structural formula in your answer booklet, circle the acid functional group, only. [1] 65 Write an IUPAC name for the reactant represented by its structural formula in this equation. [1] 66 In the space in your answer booklet, draw the structural formula for the alcohol represented by X. [1] P.S./Chem.–Aug. ’07 [10] Part C Answer all questions in this part. Directions (67–84): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 67 through 69 on the information below. Elements with atomic numbers 112 and 114 have been produced and their IUPAC names are pending approval. However, an element that would be put between these two elements on the Periodic Table has not yet been produced. If produced, this element will be identified by the symbol Uut until an IUPAC name is approved. 67 In the space in your answer booklet, draw a Lewis electron-dot diagram for an atom of Uut. [1] 68 Determine the charge of an Uut nucleus. Your response must include both the numerical value and the sign of the charge. [1] 69 Identify one element that would be chemically similar to Uut. [1] Base your answers to questions 70 through 72 on the information below. Rust on an automobile door contains Fe2O3(s). The balanced equation representing one of the reactions between iron in the door of the automobile and oxygen in the atmosphere is given below. 4Fe(s) + 3O2(g) → 2Fe2O3(s) 70 Identify the type of chemical reaction represented by this equation. [1] 71 Determine the gram-formula mass of the product of this reaction. [1] 72 Write the IUPAC name for Fe2O3. [1] P.S./Chem.–Aug. ’07 [11] [OVER] Base your answers to questions 73 through 75 on the information below. A hydrate is a compound that has water molecules within its crystal structure. The formula for the hydrate CuSO4•5H2O(s) shows that there are five moles of water for every one mole of CuSO4(s). When CuSO4•5H2O(s) is heated, the water within the crystals is released, as represented by the balanced equation below. CuSO4•5H2O(s) → CuSO4(s) + 5H2O(g) A student first masses an empty crucible (a heat-resistant container). The student then masses the crucible containing a sample of CuSO4•5H2O(s). The student repeatedly heats and masses the crucible and its contents until the mass is constant. The student’s recorded experimental data and calculations are shown below. Data and calculation before heating: mass of CuSO4•5H2O(s) and crucible – mass of crucible mass of CuSO4•5H2O(s) 21.37 g 19.24 g 2.13 g Data and calculation after heating to a constant mass: mass of CuSO4(s) and crucible – mass of crucible 20.61 g 19.24 g mass of CuSO4(s) 1.37 g Calculation to determine the mass of water: mass of CuSO4•5H2O(s) – mass of CuSO4(s) 2.13 g 1.37 g mass of H2O(g) 0.76 g 73 Identify the total number of significant figures recorded in the calculated mass of CuSO4•5H2O(s). [1] 74 In the space in your answer booklet, use the student’s data to show a correct numerical setup for calculating the percent composition by mass of water in the hydrate. [1] 75 Explain why the sample in the crucible must be heated until the constant mass is reached. [1] P.S./Chem.–Aug. ’07 [12] Base your answers to questions 76 and 77 on the information below. The equilibrium equation below is related to the manufacture of a bleaching solution. In this equation, Cl–(aq) means that chloride ions are surrounded by water molecules. Cl2(g) + 2OH–(aq) OCl–(aq) + Cl–(aq) + H2O(ᐉ) 76 In your answer booklet, use the key to draw two water molecules in the box, showing the correct orientation of each water molecule toward the chloride ion. [1] 77 Explain, in terms of collision theory, why increasing the concentration of Cl2(g) increases the concentration of OCl–(aq) in this equilibrium system. [1] Base your answers to questions 78 through 80 on the information below. In a laboratory activity, 0.500 mole of NaOH(s) is completely dissolved in distilled water to form 400. milliliters of NaOH(aq). This solution is then used to titrate a solution of HNO3(aq). 78 Identify the negative ion produced when the NaOH(s) is dissolved in distilled water. [1] 79 In the space in your answer booklet, calculate the molarity of the NaOH(aq). Your response must include both a correct numerical setup and the calculated result. [2] 80 In your answer booklet, complete the equation representing this titration reaction by writing the formulas of the products. [1] Base your answers to questions 81 and 82 on the information below. The fossilized remains of a plant were found at a construction site. The fossilized remains contain 1 16 the amount of carbon-14 that is present in a living plant. 81 Determine the approximate age of these fossilized remains. [1] 82 Complete the nuclear equation in your answer booklet for the decay of C-14. Your response must include the atomic number, the mass number, and the symbol of the missing particle. [1] P.S./Chem.–Aug. ’07 [13] [OVER] Base your answers to questions 83 and 84 on the information below. Electroplating is an electrolytic process used to coat metal objects with a more expensive and less reactive metal. The diagram below shows an electroplating cell that includes a battery connected to a silver bar and a metal spoon. The bar and spoon are submerged in AgNO3(aq). An Electroplating Cell + Battery – Wire Metal spoon Ag(s) AgNO3(aq) 83 Explain why AgNO3 is a better choice than AgCl for use in this electrolytic process. [1] 84 Explain the purpose of the battery in this cell. [1] P.S./Chem.–Aug. ’07 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Thursday, August 16, 2007 — 12:30 to 3:30 p.m., only ANSWER SHEET I Male I Female Grade Student .............................................. Sex: ........... Teacher .............................................. School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, August 16, 2007 — 12:30 to 3:30 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 16 C 19 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade. . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only 51 ___________________ 51 52 __________________________________________ 52 53 __________________________________________ 53 For Raters Only 54 __________________ 54 55 55 56 __________________ % 56 57 __________________ °C 57 58 Key = particle of the substance 58 59 __________________ min 59 60 __________________ kJ 60 [2] For Raters Only 61 _________________________________________________________________________ 61 _________________________________________________________________________ Potential Energy 62 62 Reaction Coordinate 63 _________________________________________________________________________ _________________________________________________________________________ 63 _________________________________________________________________________ 64 H H C O C OH 64 H 65 _______________________________ 65 66 66 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 67 67 68 _______________ 68 69 ________________________________________ 69 70 ________________________________________ 70 71 _______________ g/mol 71 72 ________________________________________ 72 [4] For Raters Only 73 _______________ 73 74 74 75 _________________________________________________________________________ _________________________________________________________________________ 75 _________________________________________________________________________ 76 Key = hydrogen atom = oxygen atom CI- = water molecule 76 77 _________________________________________________________________________ _________________________________________________________________________ 77 _________________________________________________________________________ [5] [OVER] For Raters Only 78 ________________________________________ 78 79 79 ________________ M 80 NaOH(aq) + HNO3(aq) → ____________ + ____________ 80 81 ________________ y 81 82 14C 6 → –10 e + ____________ 82 83 _________________________________________________________________________ _________________________________________________________________________ 83 _________________________________________________________________________ 84 _________________________________________________________________________ _________________________________________________________________________ 84 _________________________________________________________________________ Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 24, 2008 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 Which statement describes a chemical property of hydrogen gas? (1) Hydrogen gas burns in air. (2) Hydrogen gas is colorless. (3) Hydrogen gas has a density of 0.000 09 g/cm3 at STP. (4) Hydrogen gas has a boiling point of 20. K at standard pressure. 1 Which quantity identifies an element? (1) atomic number (2) mass number (3) total number of neutrons in an atom of the element (4) total number of valence electrons in an atom of the element 2 Which atom in the ground state has a partially filled second electron shell? (1) hydrogen atom (3) potassium atom (2) lithium atom (4) sodium atom 8 Which element has the greatest density at STP? (1) calcium (3) chlorine (2) carbon (4) copper 3 What is the total charge of the nucleus of a nitrogen atom? (1) +5 (3) +7 (2) +2 (4) +14 9 Which equation shows conservation of atoms? (1) (2) (3) (4) 4 Which value of an element is calculated using both the mass and the relative abundance of each of the naturally occurring isotopes of this element? (1) atomic number (3) half-life (2) atomic mass (4) molar volume 10 Which term indicates how strongly an atom attracts the electrons in a chemical bond? (1) alkalinity (2) atomic mass (3) electronegativity (4) activation energy 5 The mass of 12 protons is approximately equal to (1) 1 atomic mass unit (2) 12 atomic mass units (3) the mass of 1 electron (4) the mass of 12 electrons 11 A solid substance is an excellent conductor of electricity. The chemical bonds in this substance are most likely (1) ionic, because the valence electrons are shared between atoms (2) ionic, because the valence electrons are mobile (3) metallic, because the valence electrons are stationary (4) metallic, because the valence electrons are mobile 6 Sodium atoms, potassium atoms, and cesium atoms have the same (1) atomic radius (2) first ionization energy (3) total number of protons (4) oxidation state P.S./Chem.–Jan. ’08 H2 + O2 → H2O H2 + O2 → 2H2O 2H2 + O2 → 2H2O 2H2 + 2O2 → 2H2O [2] 19 Which formula represents an alkene? (1) C2H6 (3) C4H10 (2) C3H6 (4) C5H12 12 Magnesium nitrate contains chemical bonds that are (1) covalent, only (2) ionic, only (3) both covalent and ionic (4) neither covalent nor ionic 20 Which term refers to the difference between the potential energy of the products and the potential energy of the reactants for any chemical change? (1) heat of deposition (3) heat of reaction (2) heat of fusion (4) heat of vaporization 13 Which substance can be broken down by a chemical change? (1) antimony (3) hexane (2) carbon (4) sulfur 21 Which energy conversion occurs in a voltaic cell? (1) chemical energy to electrical energy (2) chemical energy to nuclear energy (3) electrical energy to chemical energy (4) nuclear energy to electrical energy 14 Which barium salt is insoluble in water? (1) BaCO3 (3) Ba(ClO4)2 (2) BaCl2 (4) Ba(NO3)2 15 Which unit can be used to express solution concentration? (1) J/mol (3) mol/L (2) L /mol (4) mol/s 22 Which metal is more active than Ni and less active than Zn? (1) Cu (3) Mg (2) Cr (4) Pb 16 Under which conditions of temperature and pressure is a gas most soluble in water? (1) high temperature and low pressure (2) high temperature and high pressure (3) low temperature and low pressure (4) low temperature and high pressure 23 As water is added to a 0.10 M NaCl aqueous solution, the conductivity of the resulting solution (1) decreases because the concentration of ions decreases (2) decreases, but the concentration of ions remains the same (3) increases because the concentration of ions decreases (4) increases, but the concentration of ions remains the same 17 Given the equation representing a system at equilibrium: H2O(s) H2O(ᐉ) At which temperature does this equilibrium exist at 101.3 kilopascals? (1) 0 K (3) 32 K (2) 0°C (4) 273°C 24 Which substance is an Arrhenius acid? (1) Ba(OH)2 (3) H3PO4 (2) CH3COOCH3 (4) NaCl 18 In a redox reaction, the total number of electrons lost is (1) less than the total number of electrons gained (2) greater than the total number of electrons gained (3) equal to the total number of electrons gained (4) equal to the total number of protons gained P.S./Chem.–Jan. ’08 25 Which compound releases hydroxide ions in an aqueous solution? (3) HCl (1) CH3COOH (2) CH3OH (4) KOH [3] [OVER] 29 Which list of nuclear emissions is arranged in order from the least penetrating power to the greatest penetrating power? (1) alpha particle, beta particle, gamma ray (2) alpha particle, gamma ray, beta particle (3) gamma ray, beta particle, alpha particle (4) beta particle, alpha particle, gamma ray 26 Which reaction converts an atom of one element to an atom of another element? (1) combustion (3) saponification (2) polymerization (4) transmutation 27 Which nuclear emission has the greatest mass? (1) alpha particle (3) gamma ray (2) beta particle (4) positron 30 One benefit of nuclear fission reactions is (1) nuclear reactor meltdowns (2) storage of waste materials (3) biological exposure (4) production of energy 28 Which two radioisotopes have the same decay mode? (3) 37K and 42K (1) 37Ca and 53Fe (2) 220Fr and 60Co (4) 99 Tc and 19Ne P.S./Chem.–Jan. ’08 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 Which list of elements consists of metalloids, only? (1) B, Al, Ga (3) O, S, Se (2) C, N, P (4) Si, Ge, As 37 In which compound is the ratio of metal ions to nonmetal ions 1 to 2? (1) calcium bromide (3) calcium phosphide (2) calcium oxide (4) calcium sulfide 32 Which two notations represent different isotopes of the same element? 38 What is the concentration of O2(g), in parts per million, in a solution that contains 0.008 gram of O2(g) dissolved in 1000. grams of H2O(ᐉ)? (1) 0.8 ppm (3) 80 ppm (2) 8 ppm (4) 800 ppm (1) 64Be and 94 Be (3) 14 N 7 and 146 C (2) 73 Li and 73 Li (4) 32 P 15 and 32 16 S 33 Which general trend is found in Period 2 on the Periodic Table as the elements are considered in order of increasing atomic number? (1) decreasing atomic mass (2) decreasing electronegativity (3) increasing atomic radius (4) increasing first ionization energy 39 The table below shows data for the temperature, pressure, and volume of four gas samples. Data for Four Gas Samples Gas Temperature Pressure Sample (K) (atm) 34 What is the gram-formula mass of Ca3(PO4)2? (1) 248 g/mol (3) 279 g/mol (2) 263 g/mol (4) 310. g/mol 35 What is the total number of pairs of electrons shared between the carbon atom and the oxygen atom in a molecule of methanal? (1) 1 (3) 3 (2) 2 (4) 4 A 100. 2 400. B 200. 2 200. C 100. 2 400. D 200. 4 200. Which two gas samples have the same total number of molecules? (1) A and B (3) B and C (2) A and C (4) B and D 40 At which temperature is the vapor pressure of ethanol equal to the vapor pressure of propanone at 35°C? (1) 35°C (3) 82°C (2) 60.°C (4) 95°C 36 When sodium and fluorine combine to produce the compound NaF, the ions formed have the same electron configuration as atoms of (1) argon, only (2) neon, only (3) both argon and neon (4) neither argon nor neon P.S./Chem.–Jan. ’08 Volume (mL) [5] [OVER] 41 A rigid cylinder with a movable piston contains a 2.0-liter sample of neon gas at STP. What is the volume of this sample when its temperature is increased to 30.°C while its pressure is decreased to 90. kilopascals? (1) 2.5 L (3) 1.6 L (2) 2.0 L (4) 0.22 L 46 Which volume of 0.10 M NaOH(aq) exactly neutralizes 15.0 milliliters of 0.20 M HNO3(aq)? (1) 1.5 mL (3) 3.0 mL (2) 7.5 mL (4) 30. mL 47 Which indicator, when added to a solution, changes color from yellow to blue as the pH of the solution is changed from 5.5 to 8.0? (1) bromcresol green (3) litmus (2) bromthymol blue (4) methyl orange 42 Which compound is a saturated hydrocarbon? (1) CH2CH2 (3) CH3CHO (2) CH3CH3 (4) CH3CH2OH 48 The pH of an aqueous solution changes from 4 to 3 when the hydrogen ion concentration in the solution is 43 A molecule of a compound contains a total of 10 hydrogen atoms and has the general formula CnH2n+2. Which prefix is used in the name of this compound? (1) but(3) oct(2) dec(4) pent- (1) decreased by a factor of 3 4 (2) decreased by a factor of 10 (3) increased by a factor of 4 3 (4) increased by a factor of 10 44 Reduction occurs at the cathode in (1) electrolytic cells, only (2) voltaic cells, only (3) both electrolytic cells and voltaic cells (4) neither electrolytic cells nor voltaic cells 49 Which fraction of an original 20.00-gram sample of nitrogen-16 remains unchanged after 36.0 seconds? 45 What are the products of a reaction between KOH(aq) and HCl(aq)? (1) H2 and KClO (3) KH and HClO (2) H2O and KCl (4) KOH and HCl P.S./Chem.–Jan. ’08 (1) 1 5 (3) 1 16 (2) 1 8 (4) 1 32 50 Which radioactive isotope is used in treating cancer? (1) carbon-14 (3) lead-206 (2) cobalt-60 (4) uranium-238 [6] Part B–2 Answer all questions in this part. Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 Describe one chemical property of Group 1 metals that results from the atoms of each metal having only one valence electron. [1] 52 Given the balanced equation representing a reaction: N2(g) + O2(g) + 182.6 kJ → 2NO(g) On the labeled axes in your answer booklet, draw a potential energy diagram for this reaction. [1] 53 Write one electron configuration for an atom of silicon in an excited state. 54 Write the empirical formula for the compound C8H18. P.S./Chem.–Jan. ’08 [7] [1] [1] [OVER] Base your answers to questions 55 through 57 on the information below. Atomic Diagrams of Magnesium and Aluminum Key = electron Element Lewis Electron-Dot Diagram magnesium Mg Electron-Shell Diagram 12 p 11 n Al aluminum 13 p 14 n 55 Identify one piece of information shown in the electron-shell diagrams that is not shown in the Lewis electron-dot diagrams. [1] 56 Determine the mass number of the magnesium atom represented by the electron-shell diagram. [1] 57 Explain why Lewis electron-dot diagrams are generally more suitable than electron-shell diagrams for illustrating chemical bonding. [1] P.S./Chem.–Jan. ’08 [8] Base your answers to questions 58 through 60 on the information below. A 100.0-gram sample of NaCl(s) has an initial temperature of 0°C. A chemist measures the temperature of the sample as it is heated. Heat is not added at a constant rate. The heating curve for the sample is shown below. Heating Curve for Sodium Chloride D Temperature (°C) 1465 B 801 0 E C A Time 58 Determine the temperature range over which the entire NaCl sample is a liquid. [1] 59 Identify one line segment on the curve where the average kinetic energy of the particles of the NaCl sample is changing. [1] 60 Identify one line segment on the curve where the NaCl sample is in a single phase and capable of conducting electricity. [1] Base your answers to questions 61 through 63 on the information below. A beaker contains 100.0 milliliters of a dilute aqueous solution of ethanoic acid at equilibrium. The equation below represents this system. HC2H3O2 (aq) H+(aq) + C2H3O2 –(aq) 61 Compare the rate of the forward reaction to the rate of the reverse reaction for this system. [1] 62 Describe what happens to the concentration of H+(aq) when 10 drops of concentrated HC2H3O2(aq) are added to this system. [1] 63 In the space in your answer booklet, draw a structural formula for ethanoic acid. P.S./Chem.–Jan. ’08 [9] [1] [OVER] Base your answers to questions 64 and 65 on the information below. A solution is made by completely dissolving 90. grams of KNO3(s) in 100. grams of water in a beaker. The temperature of this solution is 65°C. 64 Describe the effect on the solubility of KNO3(s) in this solution when the pressure on the solution increases. [1] 65 Determine the total mass of KNO3(s) that settles to the bottom of the beaker when the original solution is cooled to 15°C. [1] P.S./Chem.–Jan. ’08 [10] Part C Answer all questions in this part. Directions (66–83): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 66 through 68 on the information below. The compound 1,2-ethanediol can be mixed with water. This mixture is added to automobile radiators as an engine coolant. The cooling system of a small van contains 6690 grams of 1,2-ethanediol. Some properties of water and 1,2-ethanediol are given in the table below. Properties of Water and 1,2-ethanediol Water (H2O) Property gram-formula mass (g/mol) boiling point at standard pressure (°C) 1,2-ethanediol (CH2OHCH2OH) 18.0 62.0 100.0 197.2 66 Identify the class of organic compounds to which 1,2-ethanediol belongs. [1] 67 State, in terms of molecular polarity, why 1,2-ethanediol is soluble in water. [1] 68 In the space in your answer booklet, calculate the total number of moles of 1, 2-ethanediol in the small van’s cooling system. Your response must include both a correct numerical setup and the calculated result. [2] Base your answers to questions 69 through 71 on the information below. “Hand Blasters” is a toy that consists of a set of two ceramic balls, each coated with a mixture of sulfur and potassium chlorate, KClO3. When the two balls are struck together, a loud popping noise is produced as sulfur and potassium chlorate react with each other. 69 Balance the equation in your answer booklet for the “Hand Blaster” reaction, using the smallest whole-number coefficients. [1] 70 Identify one source of the activation energy for this reaction. [1] 71 Determine the oxidation number of chlorine in the reactant that contains chlorine. P.S./Chem.–Jan. ’08 [11] [1] [OVER] Base your answers to questions 72 through 74 on the information below. A laboratory worker filled a bottle with a hydrochloric acid solution. Another bottle was filled with methanol, while a third bottle was filled with a sodium hydroxide solution. However, the worker neglected to label each bottle. After a few days, the worker could not remember which liquid was in each bottle. The worker needed to identify the liquid in each bottle. The bottles were labeled A, B, and C. Using materials found in the lab (indicators, conductivity apparatus, and pieces of Mg metal), the worker tested samples of liquid from each bottle. The test results are shown in the table below. Table of Tests and Results Test Test Results Bottle A Bottle B Bottle C methyl orange indicator yellow yellow yellow bromthymol blue indicator blue green yellow electrical conductivity conductor nonconductor conductor reactivity with Mg metal no reaction no reaction reaction 72 Using the test results, state how the worker differentiated the bottle that contained methanol from the other two bottles. [1] 73 The worker concluded that bottle C contained hydrochloric acid. Identify one test and state the corresponding test result that supports this conclusion. [1] 74 Explain, in terms of pH, why the methyl orange indicator test results were the same for each of the three liquids. [1] P.S./Chem.–Jan. ’08 [12] Base your answers to questions 75 and 76 on the information below. A student performed an experiment to determine the total amount of energy stored in a peanut. The accepted value for the energy content of a peanut is 30.2 kilojoules per gram. The student measured 100.0 grams of water into a metal can and placed the can on a ring stand, as shown in the diagram below. The peanut was attached to a wire suspended under the can. The initial temperature of the water was recorded as 22.0°C. The peanut was ignited and allowed to burn. When the peanut finished burning, the final water temperature was recorded as 57.0°C. The student’s experimental value for the energy content of this peanut was 25.9 kilojoules per gram. Thermometer Metal can 100.0 g H2O( ) Peanut 75 In the space in your answer booklet, calculate the total amount of heat absorbed by the water. Your response must include both a correct numerical setup and the calculated result. [2] 76 Determine the student’s percent error for the energy content of this peanut. [1] Base your answers to questions 77 through 79 on the information below. Some dry chemicals can be used to put out forest fires. One of these chemicals is NaHCO3. When NaHCO3(s) is heated, one of the products is CO2(g), as shown in the balanced equation below. 2NaHCO3(s) + heat → Na2CO3(s) + H2O(g) + CO2 (g) 77 In the space in your answer booklet, show a correct numerical setup for calculating the percent composition by mass of carbon in the product Na2CO3. [1] 78 Identify the type of chemical reaction represented by this equation. [1] 79 Determine the total number of moles of CO2(g) produced when 7.0 moles of NaHCO3(s) is completely reacted. [1] P.S./Chem.–Jan. ’08 [13] [OVER] Base your answers to questions 80 and 81 on the information below. In an investigation, a dripless wax candle is massed and then lighted. As the candle burns, a small amount of liquid wax forms near the flame. After 10 minutes, the candle’s flame is extinguished and the candle is allowed to cool. The cooled candle is massed. 80 Identify one physical change that takes place in this investigation. [1] 81 State one observation that indicates a chemical change has occurred in this investigation. [1] Base your answers to questions 82 and 83 on the information below. The graph below shows the relationship between boiling point and molar mass at standard pressure for pentane, hexane, heptane, and nonane. Boiling Point Versus Molar Mass of Some Alkanes 160. Boiling Point (°C) 140. 120. 100. 80. 60. 40. 20. 70. 80. 90. 100. 110. 120. Molar Mass (g/mol) 82 Octane has a molar mass of 114 grams per mole. According to this graph, what is the boiling point of octane at standard pressure? [1] 83 State the relationship between molar mass and the strength of intermolecular forces for the selected alkanes. [1] P.S./Chem.–Jan. ’08 [14] 130. The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Thursday, January 24, 2008 — 1:15 to 4:15 p.m., only ANSWER SHEET I Male I Female Grade . . . . . . . . . . . . Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 24, 2008 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . . For Raters Only 51 51 Potential Energy 52 52 Reaction Coordinate For Raters Only 53 53 54 54 55 55 56 56 57 57 58 58 59 59 60 60 [2] For Raters Only 61 61 62 62 63 63 64 64 65 65 g Total Score for Part B–2 [3] [OVER] For Raters Only Part C 66 66 67 67 68 68 mol 69 _____ S(s) + _____ KClO3(s) → _____ SO2(g) + _____ KCl(s) + energy 69 70 70 71 71 [4] For Raters Only 72 72 73 Test: 73 Test result: 74 74 75 75 J 76 76 % [5] [OVER] For Raters Only 77 77 78 78 79 79 mol 80 80 81 81 82 °C 82 83 83 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Tuesday, June 17, 2008 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 Given the balanced equation representing a reaction: 1 An atom in the ground state has seven valence electrons. This atom could be an atom of which element? (1) calcium (3) oxygen (2) fluorine (4) sodium H+(aq) + OH–(aq) → H2O(ᐉ) + energy In this reaction there is conservation of (1) mass, only (2) mass and charge, only (3) charge and energy, only (4) charge, energy, and mass 2 What is the total number of electrons in an atom of potassium? (1) 18 (3) 20 (2) 19 (4) 39 8 Which statement describes the composition of potassium chlorate, KClO3? (1) The proportion by mass of elements combined in potassium chlorate is fixed. (2) The proportion by mass of elements combined in potassium chlorate varies. (3) Potassium chlorate is composed of four elements. (4) Potassium chlorate is composed of five elements. 3 A proton has a charge that is opposite the charge of (1) an alpha particle (3) an electron (2) a neutron (4) a positron 4 Which conclusion was a direct result of the gold foil experiment? (1) An atom is mostly empty space with a dense, positively charged nucleus. (2) An atom is composed of at least three types of subatomic particles. (3) An electron has a positive charge and is located inside the nucleus. (4) An electron has properties of both waves and particles. 9 As a bond between a hydrogen atom and a sulfur atom is formed, electrons are (1) shared to form an ionic bond (2) shared to form a covalent bond (3) transferred to form an ionic bond (4) transferred to form a covalent bond 5 Which statement identifies the element arsenic? (1) Arsenic has an atomic number of 33. (2) Arsenic has a melting point of 84 K. (3) An atom of arsenic in the ground state has eight valence electrons. (4) An atom of arsenic in the ground state has a radius of 146 pm. 10 Atoms of which element can bond to each other to form chains, rings, and networks? (1) carbon (3) hydrogen (2) fluorine (4) oxygen 11 Which formula represents a polar molecule? (1) Br2 (3) CH4 6 Which element has an atom with the greatest attraction for electrons in a chemical bond? (1) As (3) N (2) Bi (4) P P.S./Chem.–June ’08 (2) CO2 [2] (4) NH3 18 Which process increases the potential energy of the particles of a sample? (1) condensation (3) solidification (2) deposition (4) vaporization 12 Two solid samples each contain sulfur, oxygen, and sodium, only. These samples have the same color, melting point, density, and reaction with an aqueous barium chloride solution. It can be concluded that the two samples are the same (1) compound (3) mixture (2) element (4) solution 19 Which sample at STP has the same number of molecules as 5 liters of NO2(g) at STP? (1) 5 grams of H2(g) (2) 5 liters of CH4(g) (3) 5 moles of O2(g) (4) 5 × 1023 molecules of CO2(g) 13 Which equation represents a physical change? (1) H2O(s) + 6.01 kJ → H2O(ᐉ) (2) 2H2(g) + O2(g) → 2H2O(g) + 483.6 kJ (3) H2(g) + I2(g) + 53.0 kJ → 2HI(g) (4) N2(g) + 2O2(g) + 66.4 kJ → 2NO2(g) 20 Under which conditions of temperature and pressure does oxygen gas behave least like an ideal gas? (1) low temperature and low pressure (2) low temperature and high pressure (3) high temperature and low pressure (4) high temperature and high pressure 14 Which liquid has the lowest vapor pressure at 65°C? (1) ethanoic acid (3) propanone (2) ethanol (4) water 15 Which substance can not be broken down by a chemical reaction? (1) ammonia (3) methane (2) argon (4) water 21 How is a chemical reaction affected by the addition of a catalyst? (1) The activation energy decreases. (2) The heat of reaction increases. (3) The number of collisions between particles decreases. (4) The potential energy of the reactants increases. 16 In which sample is the average kinetic energy of the particles greatest? (1) 10. mL of HCl(aq) at 25°C (2) 15 mL of HCl(aq) at 20.°C (3) 10. mL of H2O(ᐉ) at 35°C (4) 15 mL of H2O(ᐉ) at 30.°C 22 Systems in nature tend to undergo changes toward (1) lower energy and less disorder (2) lower energy and more disorder (3) higher energy and less disorder (4) higher energy and more disorder 17 A thermometer is in a beaker of water. Which statement best explains why the thermometer reading initially increases when LiBr(s) is dissolved in the water? (1) The entropy of the LiBr(aq) is greater than the entropy of the water. (2) The entropy of the LiBr(aq) is less than the entropy of the water. (3) The dissolving of the LiBr(s) in water is an endothermic process. (4) The dissolving of the LiBr(s) in water is an exothermic process. P.S./Chem.–June ’08 23 What can be concluded if an ion of an element is smaller than an atom of the same element? (1) The ion is negatively charged because it has fewer electrons than the atom. (2) The ion is negatively charged because it has more electrons than the atom. (3) The ion is positively charged because it has fewer electrons than the atom. (4) The ion is positively charged because it has more electrons than the atom. [3] [OVER] 28 Which type of reaction occurs when a highenergy particle collides with the nucleus of an atom, converting that atom to an atom of a different element? (1) addition (3) substitution (2) neutralization (4) transmutation 24 Which class of organic compounds has molecules that contain nitrogen atoms? (1) alcohol (3) ether (2) amine (4) ketone 25 Which two compounds have the same molecular formula but different chemical and physical properties? (1) CH3CH2Cl and CH3CH2Br (2) CH3CHCH2 and CH3CH2CH3 (3) CH3CHO and CH3COCH3 (4) CH3CH2OH and CH3OCH3 29 Which particle is emitted when an atom of 85Kr spontaneously decays? (1) an alpha particle (3) a neutron (2) a beta particle (4) a proton 30 What is a problem commonly associated with nuclear power facilities? (1) A small quantity of energy is produced. (2) Reaction products contribute to acid rain. (3) It is impossible to control nuclear fission. (4) It is difficult to dispose of wastes. 26 Which half-reaction equation represents the reduction of a potassium ion? (3) K+ → K + e– (1) K+ + e– → K (2) K + e– → K+ (4) K → K+ + e– 27 According to the Arrhenius theory, an acid is a substance that (1) changes litmus from red to blue (2) changes phenolphthalein from colorless to pink (3) produces hydronium ions as the only positive ions in an aqueous solution (4) produces hydroxide ions as the only negative ions in an aqueous solution P.S./Chem.–June ’08 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 The wave-mechanical model of the atom is required to explain the (1) mass number and atomic number of an atom (2) organization of atoms in a crystal (3) radioactive nature of some atoms (4) spectra of elements with multielectron atoms 35 A student measures the mass and volume of a piece of aluminum. The measurements are 25.6 grams and 9.1 cubic centimeters. The student calculates the density of the aluminum. What is the percent error of the student’s calculated density of aluminum? (1) 1% (3) 3% (2) 2% (4) 4% 32 Magnesium and calcium have similar chemical properties because an atom of each element has the same total number of (1) electron shells (3) neutrons (2) valence electrons (4) protons 36 Given the balanced equation representing a reaction: 2H2 + O2 → 2H2O What is the total mass of water formed when 8 grams of hydrogen reacts completely with 64 grams of oxygen? 33 The diagram below represents the nucleus of an atom. (1) 18 g (2) 36 g (3) 56 g (4) 72 g Key 37 Which compound contains both ionic and covalent bonds? (1) ammonia (2) methane (3) sodium nitrate (4) potassium chloride = proton = neutron What are the atomic number and mass number of this atom? (1) The atomic number number is 19. (2) The atomic number number is 20. (3) The atomic number number is 19. (4) The atomic number number is 20. is 9 and the mass 38 An iron bar at 325 K is placed in a sample of water. The iron bar gains energy from the water if the temperature of the water is (1) 65 K (3) 65°C (2) 45 K (4) 45°C is 9 and the mass is 11 and the mass is 11 and the mass 34 A barium atom attains a stable electron configuration when it bonds with (1) one chlorine atom (2) two chlorine atoms (3) one sodium atom (4) two sodium atoms P.S./Chem.–June ’08 [5] [OVER] 42 Given the balanced equation representing a reaction: 39 Which particle model diagram represents only one compound composed of elements X and Z? C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g) Key = atom of element X = atom of element Z What is the total number of moles of O2(g) required for the complete combustion of 1.5 moles of C3H8(g)? (1) 0.30 mol (2) 1.5 mol (1) (2) 43 A sample of gas occupies a volume of 50.0 milliliters in a cylinder with a movable piston. The pressure of the sample is 0.90 atmosphere and the temperature is 298 K. What is the volume of the sample at STP? (1) 41 mL (3) 51 mL (2) 49 mL (4) 55 mL (3) 44 Which solution has the lowest freezing point? (1) 10. g of KI dissolved in 100. g of water (2) 20. g of KI dissolved in 200. g of water (3) 30. g of KI dissolved in 100. g of water (4) 40. g of KI dissolved in 200. g of water (4) 40 Given the balanced equation representing a reaction: 45 Which 1-mole sample has the least entropy? (1) Br2(s) at 266 K (3) Br2(ᐉ) at 332 K (2) Br2(ᐉ) at 266 K (4) Br2(g) at 332 K Cu + S → CuS + energy Which statement explains why the energy term is written to the right of the arrow? 46 At 20.°C, a 1.2-gram sample of Mg ribbon reacts rapidly with 10.0 milliliters of 1.0 M HCl(aq). Which change in conditions would have caused the reaction to proceed more slowly? (1) increasing the initial temperature to 25°C (2) decreasing the concentration of HCl(aq) to 0.1 M (3) using 1.2 g of powdered Mg (4) using 2.4 g of Mg ribbon (1) The compound CuS is composed of two metals. (2) The compound CuS is composed of two nonmetals. (3) Energy is absorbed as the bonds in CuS form. (4) Energy is released as the bonds in CuS form. 41 A 1.0-gram sample of which element will uniformly fill a closed 2.0-liter container at STP? (1) antimony (3) tellurium (2) sulfur (4) xenon P.S./Chem.–June ’08 (3) 4.5 mol (4) 7.5 mol 47 Which general formula represents the compound CH3CH2CCH? (3) CnH2n–2 (1) CnHn (2) CnH2n (4) CnH2n+2 [6] 50 An original sample of K-40 has a mass of 25.00 grams. After 3.9 × 109 years, 3.125 grams of the original sample remains unchanged. What is the half-life of K-40? (1) 1.3 × 109 y (3) 3.9 × 109 y (2) 2.6 × 109 y (4) 1.2 × 1010 y 48 Which compound dissolves in water to form an aqueous solution that can conduct an electric current? (1) CCl4 (3) CH3COOH (2) C2H5OH (4) CH4 49 Given the equation representing a reaction at equilibrium: NH3(g) + H2O(ᐉ) NH4+(aq) + OH–(aq) The H+ acceptor for the forward reaction is (1) H2O(ᐉ) (2) NH3(g) P.S./Chem.–June ’08 (3) NH4+(aq) (4) OH–(aq) [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–64): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 and 52 on the information below. In a titration, 15.65 milliliters of a KOH(aq) solution exactly neutralized 10.00 milliliters of a 1.22 M HCl(aq) solution. 51 Complete the equation in your answer booklet for the titration reaction by writing the formula of each product. [1] 52 In the space in your answer booklet, show a correct numerical setup for calculating the molarity of the KOH(aq) solution. [1] Base your answers to questions 53 through 55 on the information below. A 150.-gram liquid sample of stearic acid, C17H35COOH, is cooled at a constant rate. The temperature of the sample is recorded at 2-minute intervals in the data table below. Cooling Data for Stearic Acid Time (min) Temperature (°C) 0 75.0 2 72.0 4 69.3 6 69.3 8 69.3 10. 69.3 12 65.0 53 Identify the physical change occurring during the time interval 4 minutes to 10. minutes. [1] 54 On the grid in your answer booklet: • Mark an appropriate scale on the axis labeled “Temperature (°C).” [1] • Plot the data from the data table. Circle and connect the points. [1] 55 Determine the gram-formula mass of stearic acid. [1] P.S./Chem.–June ’08 [8] Base your answers to questions 56 through 58 on the information below. An unsaturated solution is made by completely dissolving 20.0 grams of NaNO3 in 100.0 grams of water at 20.0°C. 56 In the space in your answer booklet, show a correct numerical setup for calculating the number of moles of NaNO3 (gram-formula mass = 85.0 grams per mole) used to make this unsaturated solution. [1] 57 Determine the minimum mass of NaNO3 that must be added to this unsaturated solution to make a saturated solution at 20.0°C. [1] 58 Identify one process that can be used to recover the NaNO3 from the unsaturated solution. [1] Base your answers to questions 59 through 61 on the information below. The hydrocarbon 2-methylpropane reacts with iodine as represented by the balanced equation below. At standard pressure, the boiling point of 2-methylpropane is lower than the boiling point of 2-iodo-2-methylpropane. H H C H H H H H H H C C C H H H H 2-methylpropane I I H C H H C C C H I H H H I 2-iodo-2-methylpropane 59 To which class of organic compounds does this organic product belong? [1] 60 Explain, in terms of bonding, why the hydrocarbon 2-methylpropane is saturated. [1] 61 Explain the difference in the boiling points of 2-methylpropane and 2-iodo-2-methylpropane in terms of both molecular polarity and intermolecular forces. [2] P.S./Chem.–June ’08 [9] [OVER] Base your answers to questions 62 through 64 on the information below. Nitrogen gas, hydrogen gas, and ammonia gas are in equilibrium in a closed container at constant temperature and pressure. The equation below represents this equilibrium. N2(g) + 3H2(g) 2NH3(g) The graph below shows the initial concentration of each gas, the changes that occur as a result of adding H2(g) to the system, and the final concentrations when equilibrium is reestablished. Concentration of Reaction Gases Versus Time H2 added at this time Initial Final Concentration H2 NH3 N2 Time 62 What information on the graph indicates that the system was initially at equilibrium? [1] 63 Explain, in terms of LeChatelier’s principle, why the final concentration of NH3(g) is greater than the initial concentration of NH3(g). [1] 64 Explain, in terms of collision theory, why the concentration of H2(g) begins to decrease immediately after more H2(g) is added to the system. [1] P.S./Chem.–June ’08 [10] Part C Answer all questions in this part. Directions (65–79): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 65 through 67 on the information below. An unlit candle is secured to the bottom of a 200-milliliter glass beaker. Baking soda (sodium hydrogen carbonate) is added around the base of the candle as shown below. Candle Baking soda The candle is lit and dilute ethanoic acid is poured down the inside of the beaker. As the acid reacts with the baking soda, bubbles of CO2 gas form. After a few seconds, the air in the beaker is replaced by 0.20 liter of CO2 gas, causing the candle flame to go out. The density of CO2 gas is 1.8 grams per liter at room temperature. 65 Write the chemical formula for baking soda. [1] 66 In the space in your answer booklet, draw a structural formula for the acid that was poured into the beaker. [1] 67 Calculate the mass of the CO2 gas that replaced the air in the beaker. Your response must include both a correct numerical setup and the calculated result. [2] P.S./Chem.–June ’08 [11] [OVER] Base your answers to questions 68 through 71 on the information below. The health of fish depends on the amount of oxygen dissolved in the water. A dissolved oxygen (DO) concentration between 6 parts per million and 8 parts per million is best for fish health. A DO concentration greater than 1 part per million is necessary for fish survival. Fish health is also affected by water temperature and concentrations of dissolved ammonia, hydrogen sulfide, chloride compounds, and nitrate compounds. Most freshwater fish thrive in water with a pH between 6.5 and 8.5. A student’s fish tank contains fish, green plants, and 3800 grams of fish-tank water with 2.7 × 10–2 gram of dissolved oxygen. Phenolphthalein tests colorless and bromthymol blue tests blue in samples of the fish-tank water. 68 Based on the test results for the indicators phenolphthalein and bromthymol blue, what is the pH range of the fish-tank water? [1] 69 When the fish-tank water has a pH of 8.0, the hydronium ion concentration is 1.0 × 10–8 mole per liter. What is the hydronium ion concentration when the water has a pH of 7.0? [1] 70 State how an increase in the temperature of the fish-tank water affects the solubility of oxygen in the water. [1] 71 Determine if the DO concentration in the fish tank is healthy for fish. Your response must include: • a correct numerical setup to calculate the DO concentration in the water in parts per million [1] • the calculated result [1] • a statement using your calculated result that tells why the DO concentration in the water is or is not healthy for fish [1] P.S./Chem.–June ’08 [12] Base your answers to questions 72 and 73 on the information below. The Balmer series refers to the visible bright lines in the spectrum produced by hydrogen atoms. The color and wavelength of each line in this series are given in the table below. Balmer Series for Hydrogen Color Wavelength (nm) red 656.3 blue green 486.1 blue 434.1 violet 410.2 72 On the diagram in your answer booklet, draw four vertical lines to represent the Balmer series. [1] 73 Explain, in terms of both subatomic particles and energy states, how the Balmer series is produced. [1] Base your answers to questions 74 through 76 on the information below. A flashlight can be powered by a rechargeable nickel-cadmium battery. In the battery, the anode is Cd(s) and the cathode is NiO2(s). The unbalanced equation below represents the reaction that occurs as the battery produces electricity. When a nickel-cadmium battery is recharged, the reverse reaction occurs. Cd(s) + NiO2(s) + H2O(ᐉ) → Cd(OH)2(s) + Ni(OH)2(s) 74 Balance the equation in your answer booklet for the reaction that produces electricity, using the smallest whole-number coefficients. [1] 75 Determine the change in oxidation number for the element that makes up the anode in the reaction that produces electricity. [1] 76 Explain why Cd would be above Ni if placed on Table J. [1] P.S./Chem.–June ’08 [13] [OVER] Base your answers to questions 77 through 79 on the information below. A battery-operated smoke detector produces an alarming sound when its electrical sensor detects smoke particles. Some ionizing smoke detectors contain the radioisotope americium-241, which undergoes alpha decay and has a half-life of 433 years. The emitted alpha particles ionize gas molecules in the air. As a result, an electric current flows through the detector. When smoke particles enter the detector, the flow of ions is interrupted, causing the alarm to sound. 77 Complete the nuclear equation in your answer booklet for the decay of Am-241. Your response must include the symbol, mass number, and atomic number for each product. [2] 78 State one scientific reason why Am-241 is a more appropriate radioactive source than Fr-220 in an ionizing smoke detector. [1] 79 Explain, in terms of particle behavior, why smoke particles cause the detector alarm to sound. [1] P.S./Chem.–June ’08 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Tuesday, June 17, 2008 — 1:15 to 4:15 p.m., only ANSWER SHEET I Male I Female Grade . . . . . . . . . . . . Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Tuesday, June 17, 2008 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 16 C 19 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . Part B–2 51 HCl(aq) + KOH(aq) → ____________________ + ____________________ For Raters Only 51 52 52 For Raters Only 53 53 54 Temperature (°C) Cooling Curve for Stearic Acid 54 0 4 8 12 Time (min) 55 55 g/mol 56 56 57 g 57 58 58 [2] For Raters Only 59 59 60 60 61 Molecular polarity: 61 Intermolecular forces: 62 62 63 63 64 64 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 65 65 66 66 67 67 g [4] For Raters Only 68 pH between ____________ and ____________ 68 69 69 mol/L 70 70 71 71 ppm 72 400. 500. 600. 700. 72 Wavelength (nm) 73 73 [5] [OVER] For Raters Only 74 _____ Cd(s) + _____ NiO2(s) + _____ H2O(ᐉ) → _____ Cd(OH)2(s) + _____ Ni(OH)2(s) 74 75 From ____________ to ____________ 75 76 76 77 241Am 95 → ____________ + ____________ 77 78 78 79 79 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, August 13, 2008 — 12:30 to 3:30 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 Chlorine-37 can be represented as (1) 17 (3) 35 35Cl 20Cl 1 In the wave-mechanical model of the atom, orbitals are regions of the most probable locations of (1) protons (3) neutrons (2) positrons (4) electrons (2) (4) 37Cl 17 7 Which element is a metal that is in the liquid phase at STP? (1) bromine (3) hydrogen (2) cobalt (4) mercury 2 Which phrase describes an atom? (1) a positively charged electron cloud surrounding a positively charged nucleus (2) a positively charged electron cloud surrounding a negatively charged nucleus (3) a negatively charged electron cloud surrounding a positively charged nucleus (4) a negatively charged electron cloud surrounding a negatively charged nucleus 8 Which list of formulas represents compounds, only? (3) H2, Ne, NaCl (1) CO2, H2O, NH3 (2) H2, N2, O2 (4) MgO, NaCl, O2 9 What is the chemical formula for iron(III) oxide? (1) FeO (3) Fe3O (2) Fe2O3 (4) Fe3O2 3 Which total mass is the smallest? (1) the mass of 2 electrons (2) the mass of 2 neutrons (3) the mass of 1 electron plus the mass of 1 proton (4) the mass of 1 neutron plus the mass of 1 electron 10 An atom of which element has the greatest attraction for the electrons in a bond with a hydrogen atom? (1) chlorine (3) silicon (2) phosphorus (4) sulfur 4 Elements on the modern Periodic Table are arranged in order of increasing (1) atomic mass (2) atomic number (3) number of neutrons (4) number of valence electrons 11 Which property could be used to identify a compound in the laboratory? (1) mass (3) temperature (2) melting point (4) volume 5 As the elements of Group 17 are considered in order of increasing atomic number, there is an increase in (1) atomic radius (2) electronegativity (3) first ionization energy (4) number of electrons in the first shell P.S./Chem.–Aug. ’08 20Cl 37 12 Which statement describes what occurs as two atoms of bromine combine to become a molecule of bromine? (1) Energy is absorbed as a bond is formed. (2) Energy is absorbed as a bond is broken. (3) Energy is released as a bond is formed. (4) Energy is released as a bond is broken. [2] 13 Given a formula for oxygen: 19 Hydrocarbons are compounds that contain (1) carbon, only (2) carbon and hydrogen, only (3) carbon, hydrogen, and oxygen, only (4) carbon, hydrogen, oxygen, and nitrogen, only O=O What is the total number of electrons shared between the atoms represented in this formula? (1) 1 (2) 2 20 The reaction that joins thousands of small, identical molecules to form one very long molecule is called (1) esterification (3) polymerization (2) fermentation (4) substitution (3) 8 (4) 4 14 Solid ZnCl2 and liquid ZnCl2 have different (1) empirical formulas (3) ion ratios (2) formula masses (4) physical properties 21 What is the IUPAC name of the organic compound that has the formula shown below? 15 Which phrase describes the molarity of a solution? (1) liters of solute per mole of solution (2) liters of solution per mole of solution (3) moles of solute per liter of solution (4) moles of solution per liter of solution H H H C C C H 16 Which substance can not be decomposed by a chemical change? (1) AlCl3 (3) HI (2) H2O (4) Cu H C C H H H H (1) 1,1-dimethylbutane (3) hexane (2) 2-methylpentane (4) 4-methylpentane 22 A voltaic cell spontaneously converts chemical energy to (1) electrical energy (3) mechanical energy (2) geothermal energy (4) nuclear energy 17 Tetrachloromethane, CCl4, is classified as a (1) compound because the atoms of the elements are combined in a fixed proportion (2) compound because the atoms of the elements are combined in a proportion that varies (3) mixture because the atoms of the elements are combined in a fixed proportion (4) mixture because the atoms of the elements are combined in a proportion that varies 23 Given the balanced equation representing a reaction: Mg(s) + Ni2+(aq) → Mg2+(aq) + Ni(s) What is the total number of moles of electrons lost by Mg(s) when 2.0 moles of electrons are gained by Ni2+(aq)? 18 Which formulas represent two polar molecules? (1) CO2 and HCl (3) H2O and HCl (2) CO2 and CH4 (4) H2O and CH4 P.S./Chem.–Aug. ’08 H C H H H H (1) 1.0 mol (2) 2.0 mol [3] (3) 3.0 mol (4) 4.0 mol [OVER] 24 Which half-reaction correctly reduction? (1) Mn4+ → Mn3+ + e– (2) Mn4+ → Mn7+ + 3e– (3) Mn4+ + e– → Mn3+ (4) Mn4+ + 3e– → Mn7+ 28 A nuclear reaction in which two light nuclei combine to form a more massive nucleus is called (1) addition (3) fusion (2) fission (4) substitution represents 29 The nucleus of a radium-226 atom is unstable, which causes the nucleus to spontaneously (1) absorb electrons (3) decay (2) absorb protons (4) oxidize 25 Which indicator is blue in a solution that has a pH of 5.6? (1) bromcresol green (3) methyl orange (2) bromthymol blue (4) thymol blue 30 A serious risk factor associated with the operation of a nuclear power plant is the production of (1) acid rain (2) helium gas (3) greenhouse gases, such as CO2 (4) radioisotopes with long half-lives 26 The Arrhenius theory explains the behavior of (1) acids and bases (2) alcohols and amines (3) isomers and isotopes (4) metals and nonmetals 27 In which laboratory process could a student use 0.10 M NaOH(aq) to determine the concentration of an aqueous solution of HBr? (1) chromatography (2) decomposition of the solute (3) evaporation of the solvent (4) titration P.S./Chem.–Aug. ’08 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 38 Which balanced equation represents a chemical change? (1) H2O(ᐉ) + energy → H2O(g) (2) 2H2O(ᐉ) + energy → 2H2(g) + O2(g) (3) H2O(ᐉ) → H2O(s) + energy (4) H2O(g) → H2O(ᐉ) + energy 31 What is the total number of protons in an atom with the electron configuration 2-8-18-32-18-1? (1) 69 (3) 118 (2) 79 (4) 197 32 Which two elements have the most similar chemical properties? (1) Be and Mg (3) Cl and Ar (2) Ca and Br (4) Na and P 39 When 5 grams of KCl are dissolved in 50. grams of water at 25°C, the resulting mixture can be described as (1) heterogeneous and unsaturated (2) heterogeneous and supersaturated (3) homogeneous and unsaturated (4) homogeneous and supersaturated 33 In the ground state, each atom of an element has two valence electrons. This element has a lower first ionization energy than calcium. Where is this element located on the Periodic Table? (1) Group 1, Period 4 (3) Group 2, Period 3 (2) Group 2, Period 5 (4) Group 3, Period 4 40 Which aqueous solution of KI freezes at the lowest temperature? (1) 1 mol of KI in 500. g of water (2) 2 mol of KI in 500. g of water (3) 1 mol of KI in 1000. g of water (4) 2 mol of KI in 1000. g of water 34 Which equation shows conservation of mass and charge? (1) NH4Br → NH3 + Br2 (2) 2Mg + Fe3+ → Mg2+ + 3Fe (3) H2SO4 + LiOH → Li2SO4 + H2O (4) Cu + 2Ag+ → Cu2+ + 2Ag 41 Which compound is a member of the same homologous series as C3H8? (3) C5H8 (1) CH4 (2) C4H8 (4) C5H10 35 What is the percent composition by mass of hydrogen in NH4HCO3 (gram-formula mass = 79 grams/mole)? (1) 5.1% (3) 10.% (2) 6.3% (4) 50.% 42 Which equation represents an oxidationreduction reaction? (1) CH4 + 2O2 → CO2 + 2H2O (2) H2SO4 + Ca(OH)2 → CaSO4 + 2H2O (3) MgCrO4 + BaCl2 → MgCl2 + BaCrO4 (4) Zn(NO3)2 + Na2CO3 → 2NaNO3 + ZnCO3 36 What is the total number of valence electrons in a sulfide ion in the ground state? (1) 8 (3) 16 (2) 2 (4) 18 37 A temperature of 37°C is equivalent to a temperature of (1) 98.6 K (3) 310. K (2) 236 K (4) 371 K P.S./Chem.–Aug. ’08 [5] [OVER] 46 Given the balanced equation representing a reaction: 43 Given the balanced equation representing a reaction: 2KClO3(s) → 2KCl(s) + 3O2(g) NH3(g) + H2O(ᐉ) → NH4+(aq) + OH–(aq) The oxidation state of chlorine in this reaction changes from According to one acid-base theory, the NH3(g) molecules act as (1) –1 to +1 (2) –1 to +5 (1) (2) (3) (4) (3) +1 to –1 (4) +5 to –1 44 The potential energy diagram for a chemical reaction is shown below. Potential Energy (kJ) 47 What volume of 0.120 M HNO3(aq) is needed to completely neutralize 150.0 milliliters of 0.100 M NaOH(aq)? (1) 62.5 mL (3) 180. mL (2) 125 mL (4) 360. mL 48 Given the balanced equation representing a nuclear reaction: 235U 92 (1) Each interval on the axis labeled “Potential Energy (kJ)” represents 40 kilojoules. What is the heat of reaction? (1) −120 kJ (2) −40 kJ (2) 0 −1e 1H 1 (3) 42He (4) 10n 49 An original sample of the radioisotope fluorine-21 had a mass of 80.0 milligrams. Only 20.0 milligrams of this original sample remain unchanged after 8.32 seconds. What is the half-life of fluorine-21? (1) 1.04 s (3) 4.16 s (2) 2.08 s (4) 8.32 s (3) +40 kJ (4) +160 kJ 45 Given the balanced equation representing a reaction occurring in an electrolytic cell: 2NaCl(ᐉ) → 2Na(ᐉ) + Cl2(g) 50 Which nuclide is paired with a specific use of that nuclide? (1) carbon-14, treatment of cancer (2) cobalt-60, dating of rock formations (3) iodine-131, treatment of thyroid disorders (4) uranium-238, dating of once-living organisms Where is Na(ᐉ) produced in the cell? at the anode, where oxidation occurs at the anode, where reduction occurs at the cathode, where oxidation occurs at the cathode, where reduction occurs P.S./Chem.–Aug. ’08 91 + 10n → 142 56Ba + 36Kr + 3X + energy Which particle is represented by X? Reaction Coordinate (1) (2) (3) (4) an acid because they accept H+ ions an acid because they donate H+ ions a base because they accept H+ ions a base because they donate H+ ions [6] Part B–2 Answer all questions in this part. Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 Identify one ion from Table F that can combine with Pb2+(aq) to produce an insoluble compound. [1] 52 Describe one appropriate laboratory test that can be used to determine the malleability of a solid sample of an element at room temperature. [1] 53 State two methods to increase the rate of a chemical reaction and explain, in terms of particle behavior, how each method increases the reaction rate. [2] Base your answers to questions 54 through 57 on the information below. Naturally Occurring Isotopes of Copper Isotope Notation Percent Natural Abundance (%) Atomic Mass (atomic mass units, u) Cu-63 69.17 62.930 Cu-65 30.83 64.928 54 State, in terms of subatomic particles, how an atom of Cu-63 differs from an atom of Cu-65. [1] 55 What is the total number of electrons in an atom of Cu-65? [1] 56 The atomic mass of Cu-63 is expressed to what number of significant figures? [1] 57 In the space in your answer booklet, show a correct numerical setup for calculating the atomic mass of copper. [1] P.S./Chem.–Aug. ’08 [7] [OVER] Base your answers to questions 58 and 59 on the information below. The boiling point of a liquid is the temperature at which the vapor pressure of the liquid is equal to the pressure on the surface of the liquid. The heat of vaporization of ethanol is 838 joules per gram. A sample of ethanol has a mass of 65.0 grams and is boiling at 1.00 atmosphere. 58 Based on Table H, what is the temperature of this sample of ethanol? [1] 59 Calculate the minimum amount of heat required to completely vaporize this sample of ethanol. Your response must include both a correct numerical setup and the calculated result. [2] Base your answers to questions 60 through 62 on the information below. The equation below represents the reaction between butanoic acid and an unidentified reactant, X. H H H H O C C C C H H H OH + X H H H H O C C C C H H H O H H C C H H H + H O 60 Identify the type of organic reaction represented by the equation. [1] 61 Write the molecular formula of the organic product in the equation. [1] 62 In the space in your answer booklet, draw a structural formula for the unidentified reactant, X, in the equation. [1] P.S./Chem.–Aug. ’08 [8] H Base your answers to questions 63 through 65 on the information below. A piece of magnesium ribbon is reacted with excess hydrochloric acid to produce aqueous magnesium chloride and hydrogen gas. The volume of the dry hydrogen gas produced is 45.6 milliliters. The temperature of the gas is 293 K, and the pressure is 99.5 kilopascals. 63 Balance the equation in your answer booklet, using the smallest whole-number coefficients. [1] 64 Identify the type of bond between the atoms in a molecule of the gas produced in this laboratory investigation. [1] 65 Calculate the volume this dry hydrogen gas would occupy at STP. Your response must include both a correct numerical setup and the calculated result. [2] P.S./Chem.–Aug. ’08 [9] [OVER] Part C Answer all questions in this part. Directions (66–80): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 66 through 69 on the information below. In a laboratory, a glass tube is filled with hydrogen gas at a very low pressure. When a scientist applies a high voltage between metal electrodes in the tube, light is emitted. The scientist analyzes the light with a spectroscope and observes four distinct spectral lines. The table below gives the color, frequency, and energy for each of the four spectral lines. The unit for frequency is hertz, Hz. Visible Spectrum of Hydrogen Frequency (× 1014 Hz) Energy (× 10–19 J) red 4.6 3.0 blue green 6.2 4.1 blue 6.9 4.6 violet 7.3 4.8 Color 66 On the grid in your answer booklet, plot the data from the data table for frequency and energy. Circle and connect the points, including the point (0,0) that has already been plotted and circled for you. [1] 67 A spectral line in the infrared region of the spectrum of hydrogen has a frequency of 2.3 × 1014 hertz. Using your graph, estimate the energy associated with this spectral line. [1] 68 Explain, in terms of subatomic particles and energy states, why light is emitted by the hydrogen gas. [1] 69 Identify one condition not mentioned in the passage, under which hydrogen gas behaves most like an ideal gas. [1] P.S./Chem.–Aug. ’08 [10] Base your answers to questions 70 through 72 on the information below. Carbon and oxygen are examples of elements that exist in more than one form in the same phase. Graphite and diamond are two crystalline arrangements for carbon. The crystal structure of graphite is organized in layers. The bonds between carbon atoms within each layer of graphite are strong. The bonds between carbon atoms that connect different layers of graphite are weak because the shared electrons in these bonds are loosely held by the carbon atoms. The crystal structure of diamond is a strong network of atoms in which all the shared electrons are strongly held by the carbon atoms. Graphite is an electrical conductor, but diamond is not. At 25°C, graphite has a density of 2.2 g/cm3 and diamond has a density of 3.51 g/cm3. The element oxygen can exist as diatomic molecules, O2, and as ozone, O3. At standard pressure the boiling point of ozone is 161 K. 70 Explain, in terms of electrons, why graphite is an electrical conductor and diamond is not. Your response must include information about both graphite and diamond. [1] 71 Calculate the volume, in cm3, of a diamond at 25°C that has a mass of 0.200 gram. Your response must include both a correct numerical setup and the calculated result. [2] 72 Explain, in terms of intermolecular forces, the difference in the boiling points of O2 and O3 at standard pressure. Your response must include information about both O2 and O3. [1] P.S./Chem.–Aug. ’08 [11] [OVER] Base your answers to questions 73 through 76 on the information below. A portable propane-fueled lantern contains a mesh silk bag coated with metal hydroxides. The primary metal hydroxide is yttrium hydroxide. When the silk bag is installed, it is ignited and burned away, leaving the metal hydroxide coating. The coating forms metal oxides that glow brightly when heated to a high temperature. During a test, a propane lantern is operated for three hours and consumes 5.0 moles of propane from the lantern’s tank. The balanced equation below represents the combustion of propane. C3H8 + 5O2 → 3CO2 + 4H2O + energy 73 At standard pressure, the boiling point of propane is 231 K. In the box in your answer booklet, draw a particle diagram to represent the phase of the propane as it leaves the tank at 294 K. Your response must include at least six molecules. [1] 74 Calculate the total mass of propane consumed during the lantern test. Your response must include both a correct numerical setup and the calculated result. [2] 75 Determine the total number of moles of CO2 produced during the lantern test. [1] 76 Write the formula for the primary metal hydroxide used in the lantern. [1] Base your answers to questions 77 through 80 on the information below. When a person perspires (sweats), the body loses many sodium ions and potassium ions. The evaporation of sweat cools the skin. After a strenuous workout, people often quench their thirst with sports drinks that contain NaCl and KCl. A single 250.-gram serving of one sports drink contains 0.055 gram of sodium ions. 77 In the space in your answer booklet, show a correct numerical setup for calculating the concentration of sodium ions in this sports drink, expressed as percent by mass. [1] 78 Describe the transfer of energy between the skin and the surroundings as a person perspires and the sweat evaporates. [1] 79 State why the salts in sports drinks are classified as electrolytes. [1] 80 In the space in your answer booklet, draw a Lewis electron-dot diagram for one of the positive ions lost by the body as a person perspires. [1] P.S./Chem.–Aug. ’08 [12] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, August 13, 2008 — 12:30 to 3:30 p.m., only ANSWER SHEET I Male I Female Grade . . . . . . . . . . . . Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, August 13, 2008 — 12:30 to 3:30 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 18 C 17 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 51 __________________________________ Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . For Raters Only 51 52 52 53 Method and explanation 1: 53 Method and explanation 2: For Raters Only 54 54 55 55 56 56 57 57 58 58 °C 59 59 J [2] For Raters Only 60 60 61 61 62 62 63 _____ Mg(s) + _____ HCl(aq) → _____ MgCl2(aq) + _____ H2(g) 63 64 64 65 65 mL Total Score for Part B–2 [3] [OVER] For Raters Only Part C 66 Light Energy Versus Frequency 5.0 Energy (× 10–19 J) 4.0 3.0 66 2.0 1.0 0 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Frequency (× 1014 Hz) 67 67 × 10–19 J 68 68 69 69 [4] For Raters Only 70 70 71 71 cm3 72 72 [5] [OVER] For Raters Only 73 Key = propane molecule 73 74 74 g 75 75 mol 76 76 [6] For Raters Only 77 77 78 78 79 79 80 80 Total Score for Part C [7] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 29, 2009 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 What can be determined if only the atomic number of an atom is known? (1) the total number of neutrons in the atom, only (2) the total number of protons in the atom, only (3) the total number of protons and the total number of neutrons in the atom (4) the total number of protons and the total number of electrons in the atom 1 On the modern Periodic Table, the elements are arranged in order of increasing (1) atomic mass (3) mass number (2) atomic number (4) oxidation number 2 Which particle has a mass that is approximately the same as the mass of a proton? (1) an alpha particle (3) a neutron (2) a beta particle (4) a positron 3 An atom of an element forms a 2+ ion. In which group on the Periodic Table could this element be located? (1) 1 (3) 13 (2) 2 (4) 17 7 The most common isotope of chromium has a mass number of 52. Which notation represents a different isotope of chromium? 4 Which statement describes the relative energy of the electrons in the shells of a calcium atom? (1) An electron in the first shell has more energy than an electron in the second shell. (2) An electron in the first shell has the same amount of energy as an electron in the second shell. (3) An electron in the third shell has more energy than an electron in the second shell. (4) An electron in the third shell has less energy than an electron in the second shell. 52Cr 24 (3) 24Cr 52 (2) 54Cr 24 (4) 24Cr 54 8 Which Group 14 element is a metalloid? (1) tin (3) lead (2) silicon (4) carbon 9 Samples of four Group 15 elements, antimony, arsenic, bismuth, and phosphorus, are in the gaseous phase. An atom in the ground state of which element requires the least amount of energy to remove its most loosely held electron? (1) As (3) P (2) Bi (4) Sb 5 According to the electron-cloud model of the atom, an orbital is a (1) circular path traveled by an electron around the nucleus (2) spiral path traveled by an electron toward the nucleus (3) region of the most probable proton location (4) region of the most probable electron location P.S./Chem.–Jan. ’09 (1) 10 Which substance can be broken down by chemical means? (1) CO (3) Ca (2) Ce (4) Cu 11 During all chemical reactions, mass, energy, and charge are (1) absorbed (3) formed (2) conserved (4) released [2] 19 The net energy released or absorbed during a reversible chemical reaction is equal to (1) the activation energy of the endothermic reaction (2) the activation energy of the exothermic reaction (3) the difference between the potential energy of the products and the potential energy of the reactants (4) the sum of the potential energy of the products and the potential energy of the reactants 12 Which formula represents a molecular compound? (1) Kr (3) N2O4 (2) LiOH (4) NaI 13 The bonds in BaO are best described as (1) covalent, because valence electrons are shared (2) covalent, because valence electrons are transferred (3) ionic, because valence electrons are shared (4) ionic, because valence electrons are transferred 20 A catalyst lowers the activation energy of a reaction by (1) providing an alternate reaction pathway (2) decreasing the heat of reaction (3) increasing the mass of the reactants (4) changing the mole ratio of the reactants 14 In which sample of water do the molecules have the highest average kinetic energy? (1) 20. mL at 100.°C (3) 60. mL at 60.°C (2) 40. mL at 80.°C (4) 80. mL at 40.°C 15 Which compound is insoluble in water? (1) calcium bromide (3) silver bromide (2) potassium bromide (4) sodium bromide 21 Which element is present in every organic compound? (1) carbon (3) nitrogen (2) fluorine (4) oxygen 16 Which element is a brittle solid with low conductivity at STP? (1) sulfur (3) argon (2) sodium (4) aluminum 22 Given the balanced equation representing a reaction: 2Fe + 3Cu2+ → 2Fe3+ + 3Cu 17 Which two samples of gas at STP contain the same total number of molecules? (1) 1 L of CO(g) and 0.5 L of N2(g) (2) 2 L of CO(g) and 0.5 L of NH3(g) (3) 1 L of H2(g) and 2 L of Cl2(g) (4) 2 L of H2(g) and 2 L of Cl2(g) When the iron atoms lose six moles of electrons, how many moles of electrons are gained by the copper ions? (1) 12 moles (2) 2 moles 18 A reaction is most likely to occur when reactant particles collide with (1) proper energy, only (2) proper orientation, only (3) both proper energy and proper orientation (4) neither proper energy nor proper orientation P.S./Chem.–Jan. ’09 (3) 3 moles (4) 6 moles 23 Which statement describes electrolysis? (1) Chemical energy is used to produce an electrical change. (2) Chemical energy is used to produce a thermal change. (3) Electrical energy is used to produce a chemical change. (4) Thermal energy is used to produce a chemical change. [3] [OVER] 24 During which process does an atom gain one or more electrons? (1) transmutation (3) oxidation (2) reduction (4) neutralization 28 The only positive ion found in H2SO4(aq) is the (1) ammonium ion (3) hydroxide ion (2) hydronium ion (4) sulfate ion 29 Which risk is associated with using nuclear fission to produce energy in a power plant? (1) depletion of hydrocarbons (2) depletion of atmospheric oxygen (3) exposure of workers to radiation (4) exposure of workers to sulfur dioxide 25 Which substance is an Arrhenius base? (3) LiOH (1) CH3OH (2) CH3Cl (4) LiCl 26 Which statement describes an alternate theory of acids and bases? (1) Acids and bases are both H+ acceptors. (2) Acids and bases are both H+ donors. (3) Acids are H+ acceptors, and bases are H+ donors. (4) Acids are H+ donors, and bases are H+ acceptors. 30 An unstable nucleus loses the most mass if the nucleus emits (1) an alpha particle (3) a positron (2) a beta particle (4) a gamma ray 27 Which two compounds are electrolytes? (1) C6H12O6 and CH3CH2OH (2) C6H12O6 and HCl (3) NaOH and HCl (4) NaOH and CH3CH2OH P.S./Chem.–Jan. ’09 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 The diagram below represents the bright-line spectra of four elements and a bright-line spectrum produced by a mixture of two of these elements. Bright-Line Spectra 400 500 600 700 750 700 750 Barium Helium Hydrogen Lithium Mixture 400 500 600 Wavelength (nm) Which two elements are in this mixture? (1) barium and hydrogen (2) barium and lithium 33 What is the total number of valence electrons in an atom of germanium in the ground state? (1) 8 (3) 14 (2) 2 (4) 4 32 The table below gives information about the nucleus of each of four atoms. Nuclei of Four Atoms Atom Number of Protons Number of Neutrons A 6 6 D 6 7 E 7 7 G 7 8 (3) helium and hydrogen (4) helium and lithium 34 In the formula X2O5, the symbol X could represent an element in Group (1) 1 (3) 15 (2) 2 (4) 18 How many different elements are represented by the nuclei in the table? (1) 1 (2) 2 P.S./Chem.–Jan. ’09 (3) 3 (4) 4 [5] [OVER] 35 A 50.0-gram block of copper at 10.0°C is carefully lowered into 100.0 grams of water at 90.0°C in an insulated container. Which statement describes the transfer of heat in this system? (1) The water loses heat to the block until both are at 10.0°C. (2) The block gains heat from the water until both are at 90.0°C. (3) The water loses heat and the block gains heat until both are at the same temperature that is between 10.0°C and 90.0°C. (4) The water gains heat and the block loses heat until both are at the same temperature that is between 10.0°C and 90.0°C. 41 Which particle diagram represents a mixture of an element and a compound? Key = an atom of an element = an atom of a different element (1) (3) (2) (4) 36 The compounds C2H4 and C4H8 have the same (1) freezing point at standard pressure (2) boiling point at standard pressure (3) molecular formula (4) empirical formula 37 The chemical bond between which two atoms is most polar? (1) C–N (3) S–Cl (2) H–H (4) Si–O 42 Starting as a solid, a sample of a substance is heated at a constant rate. The graph below shows the changes in temperature of this sample. 38 What is the total amount of heat absorbed by 100.0 grams of water when the temperature of the water is increased from 30.0°C to 45.0°C? (1) 418 J (3) 12 500 J (2) 6270 J (4) 18 800 J Temperature Versus Time for a Sample 200 Temperature (°C) 180 39 Which process is exothermic? (1) boiling of water (2) melting of copper (3) condensation of ethanol vapor (4) sublimation of iodine 160 140 120 100 80 60 40 20 40 Which sample, when dissolved in 1.0 liter of water, produces a solution with the lowest freezing point? (1) 0.1 mol of C2H5OH (2) 0.1 mol of LiBr (3) 0.2 mol of C6H12O6 (4) 0.2 mol of CaCl2 P.S./Chem.–Jan. ’09 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Time (min) What is the melting point of the sample and the total time required to completely melt the sample after it has reached its melting point? (1) 50°C and 3 min (2) 50°C and 5 min [6] (3) 110°C and 4 min (4) 110°C and 14 min 43 Which compound is an alkyne? (3) C4H8 (1) C2H2 (2) C2H4 (4) C4H10 48 Which nuclide has a half-life that is less than one minute? (1) cesium-137 (3) phosphorus-32 (2) francium-220 (4) strontium-90 44 What is the oxidation number of sulfur in Na2S2O3? (1) −1 (3) +6 (2) +2 (4) +4 49 The table below indicates the stability of six nuclides. Stability of Six Nuclides Nuclide 45 Which formula represents an unsaturated hydrocarbon? H H H C C H C H H H H H H C C C H H H (1) (3) H H H H C C C H H H (2) Cl H H H O H C C C H H Stability C-12 stable C-14 unstable N-14 stable N-16 unstable O-16 stable O-19 unstable All atoms of the unstable nuclides listed in this table have H (1) (2) (3) (4) (4) 46 Which balanced equation represents a redox reaction? (1) PCl5 → PCl3 + Cl2 (2) KOH + HCl → KCl + H2O (3) LiBr → Li+ + Br− (4) Ca2+ + SO42− → CaSO4 an odd number of neutrons an odd number of protons more neutrons than protons more protons than neutrons 50 Cobalt-60 and iodine-131 are radioactive isotopes that are used in (1) dating geologic formations (2) industrial measurements (3) medical procedures (4) nuclear power 47 A 25.0-milliliter sample of HNO3(aq) is neutralized by 32.1 milliliters of 0.150 M KOH(aq). What is the molarity of the HNO3(aq)? (1) 0.117 M (3) 0.193 M (2) 0.150 M (4) 0.300 M P.S./Chem.–Jan. ’09 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–66): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 In the box in your answer booklet, draw a Lewis electron-dot diagram for an atom of boron. [1] 52 Explain, in terms of atomic structure, why the noble gas neon is an unreactive element. [1] 53 Given the equation representing a reaction at equilibrium: N2(g) + 3H2(g) 2NH3(g) Explain, in terms of collision theory, why the rate of the forward reaction decreases when the concentration of N2(g) is decreased. [1] Base your answers to questions 54 and 55 on the information below. A 4.86-gram sample of calcium reacted completely with oxygen to form 6.80 grams of calcium oxide. This reaction is represented by the balanced equation below. 2Ca(s) + O2(g) → 2CaO(s) 54 Determine the total mass of oxygen that reacted. [1] 55 Explain, in terms of electrons, why the radius of a calcium ion is smaller than the radius of a calcium atom. [1] P.S./Chem.–Jan. ’09 [8] Base your answers to questions 56 through 58 on the information below. The compounds NH4Br(s) and NH3(g) are soluble in water. Solubility data for NH4Br(s) in water are listed in the table below. Solubility of NH4Br in H2O Mass of NH4Br Temperature per 100. g of H2O (°C) (g) 0 60. 20. 75. 40. 90. 60. 105. 80. 120. 100. 135. 56 On the grid in your answer booklet, plot the data from the data table. Circle and connect the points. [1] 57 Determine the total mass of NH4Br(s) that must be dissolved in 200. grams of H2O at 60.°C to produce a saturated solution. [1] 58 Compare the solubilities of NH4Br(s) and NH3(g), each in 100. grams of H2O, as temperature increases at standard pressure. Your response must include both NH4Br(s) and NH3(g). [1] Base your answers to questions 59 through 61 on the information below. Carbon forms molecular compounds with some elements from Group 16. Two of these compounds are carbon dioxide, CO2, and carbon disulfide, CS2. Carbon dioxide is a colorless, odorless gas at room temperature. At standard temperature and pressure, CO2(s) changes directly to CO2(g). Carbon disulfide is formed by a direct reaction of carbon and sulfur. At room temperature, CS2 is a colorless liquid with an offensive odor. Carbon disulfide vapors are flammable. 59 Identify one physical property and one chemical property of CS2. [1] 60 State what happens to the potential energy of CO2 molecules during this phase change of CO2. [1] 61 Compare the intermolecular forces in CO2 and CS2 at room temperature. [1] P.S./Chem.–Jan. ’09 [9] [OVER] Base your answers to questions 62 through 64 on the data table below. Formulas and Boiling Points of Selected Alkanes Name Formula Boiling Point at 1 Atm (°C) methane CH4 –162 ethane C2H6 –89 propane C3H8 –42 butane C4H10 –0.5 pentane C5H12 36 62 In the space in your answer booklet, draw a structural formula for butane. [1] 63 At standard pressure and 298 K, which alkane is a liquid? [1] 64 What is the boiling point of propane at 1 atmosphere, in kelvins? [1] Base your answers to questions 65 and 66 on the information below. The balanced equation below represents the reaction between magnesium metal and hydrochloric acid to produce aqueous magnesium chloride and hydrogen gas. Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) A piece of Mg(s) has a volume of 0.0640 cubic centimeters. This piece of Mg(s) reacts completely with HCl(aq) to produce H2(g). The H2(g) produced has a volume of 112 milliliters and a pressure of 1.00 atmosphere at 298 K. 65 The volume of the piece of Mg(s) is expressed to what number of significant figures? [1] 66 In the space in your answer booklet, show a correct numerical setup for calculating the volume of the H2(g) produced if the conditions are changed to STP. [1] P.S./Chem.–Jan. ’09 [10] Part C Answer all questions in this part. Directions (67–81): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 67 and 68 on the information below. Underground iron pipes in contact with moist soil are likely to corrode. This corrosion can be prevented by applying the principles of electrochemistry. Connecting an iron pipe to a magnesium block with a wire creates an electrochemical cell. The magnesium block acts as the anode and the iron pipe acts as the cathode. A diagram of this system is shown below. Cross-Sectional View of Underground Pipe Protection System Ground level Moist sand and gravel Wire Mg block Fe pipe Moist soil 67 State the direction of the flow of electrons between the electrodes in this cell. [1] 68 Explain, in terms of reactivity, why magnesium is preferred over zinc to protect underground iron pipes. Your response must include both magnesium and zinc. [1] P.S./Chem.–Jan. ’09 [11] [OVER] Base your answers to questions 69 through 71 on the information below. In a laboratory, 0.100 mole of colorless hydrogen iodide gas at room temperature is placed in a 1.00-liter flask. The flask is sealed and warmed, causing the HI(g) to start decomposing to H2(g) and I2(g). Then the temperature of the contents of the flask is kept constant. During this reaction, the contents of the flask change to a pale purple-colored mixture of HI(g), H2(g), and I2(g). When the color of the mixture in the flask stops changing, the concentration of I2(g) is determined to be 0.013 mole per liter. The relationship between concentration and time for the reactant and products is shown in the graph below. Concentration of Reactant and Products Versus Time 0.100 0.090 Concentration (M) 0.080 Reactant 0.070 0.060 0.050 0.040 0.030 0.020 Each product 0.010 0.000 Time 69 Write a balanced equation to represent the decomposition reaction occurring in the flask. [1] 70 State, in terms of concentration, evidence that indicates the system in the flask has reached equilibrium. [1] 71 Calculate the mass of I2(g) in the flask at equilibrium. Your response must include both a correct numerical setup and the calculated result. [2] P.S./Chem.–Jan. ’09 [12] Base your answers to questions 72 through 74 on the information below. Soil pH can affect the development of plants. For example, a hydrangea plant produces blue flowers when grown in acidic soil but pink flowers when grown in basic soil. Evergreen plants can show a yellowing of foliage, called chlorosis, when grown in soil that is too basic. Acidic soil can be neutralized by treating it with calcium hydroxide, Ca(OH)2, commonly called slaked lime. Slaked lime is slightly soluble in water. 72 Compare the hydrogen ion concentration to the hydroxide ion concentration in soil when a hydrangea plant produces pink flowers. [1] 73 An evergreen plant has yellowing foliage. The soil surrounding the plant is tested with methyl orange and bromthymol blue. Both indicators turn yellow in the soil tests. State, in terms of pH value, why the yellowing of the plant is not due to chlorosis. [1] 74 Write an equation, using symbols or words, for the neutralization of the ions in acidic soil by the ions released by slaked lime in water. [1] Base your answers to questions 75 through 77 on the information below. A fluorescent light tube contains a noble gas and a drop of mercury. When the fluorescent light operates, the Hg is a vapor and there are free-flowing Hg ions and electrons in the tube. The electrons collide with Hg atoms that then emit ultraviolet (UV) radiation. The inside of the tube is coated with a mixture of several compounds that absorbs UV radiation. Ions in the coating emit a blend of red, green, and blue light that together appears as white light. The compound that produces red light is Y2O3. The compound that produces green light is CeMgAl11O19. The compound that produces blue light is BaMgAl10O17. 75 Write the chemical name of the compound that produces red light. [1] 76 Calculate the percent composition by mass of aluminum in the compound that produces green light. Your response must include both a correct numerical setup and the calculated result. [2] 77 Explain, in terms of both electrons and energy, how ions in the coating emit light. [1] P.S./Chem.–Jan. ’09 [13] [OVER] Base your answers to questions 78 and 79 on the information below. A substance known as heavy water can be obtained from ordinary water and could be a significant source of energy in the future. Heavy water contains deuterium, H-2. Instead of the two hydrogen atoms in a typical water molecule, a heavy water molecule has two deuterium atoms. In 3.78 kilograms of ordinary water, the percent composition by mass of heavy water is approximately 0.0156%. Deuterium atoms completely ionize at approximately 108 K. The result is an ionized gas consisting of electrons and deuterons (the nuclei of deuterium). A triton is the nucleus of a tritium atom, H-3. These particles react according to the equations below. In the second equation, X represents an unidentified product. 2H 1 + 21H → 31H + 11H + energy 2H 1 + 31H → 42He + X + energy 78 Calculate the mass of heavy water in a 3.78-kilogram sample of ordinary water. Your response must include both a correct numerical setup and the calculated result. [2] 79 Identify particle X in the second nuclear equation. Your response must include the symbol, atomic number, and mass number of the particle. [1] Base your answers to questions 80 and 81 on the information below. Ethyl butanoate is an organic compound that contributes to the odor of pineapple. Ethyl butanoate is one of the products formed by the reaction of butanoic acid with ethanol. 80 Identify two differences in the structures between a molecule of butanoic acid and a molecule of ethanol. Each of your responses must include both compounds. [2] 81 Identify the type of organic reaction that produces the compound that contributes to the odor of pineapple. [1] P.S./Chem.–Jan. ’09 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Thursday, January 29, 2009 — 1:15 to 4:15 p.m., only ANSWER SHEET I Male I Female Grade . . . . . . . . . . . . Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 29, 2009 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 16 C 19 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . For Raters Only 51 51 52 52 53 53 For Raters Only 54 g 54 55 55 56 Solubility of NH4Br in H2O Versus Temperature Mass of NH4Br per 100. g of H2O (g) 150. 120. 90. 56 60. 30. 0 0 10. 20. 30. 40. 50. 60. 70. 80. 90. 100. Temperature (°C) 57 57 g 58 58 [2] For Raters Only 59 Physical property: 59 Chemical property: 60 60 61 61 62 62 63 __________________________________ 63 64 64 K 65 65 66 66 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 67 67 68 68 69 69 70 70 71 71 g [4] For Raters Only 72 72 73 73 74 74 75 75 76 76 % 77 77 [5] [OVER] For Raters Only 78 78 kg 79 79 80 Difference 1: 80 Difference 2: 81 81 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 17, 2009 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 1 Which subatomic particle is negatively charged? (1) electron (3) positron (2) neutron (4) proton 8 An atom in the ground state has a stable valence electron configuration. This atom could be an atom of (1) Al (3) Na (2) Cl (4) Ne 2 Which element has the greatest density at STP? (1) barium (3) magnesium (2) beryllium (4) radium 9 An atom of an element has a total of 12 electrons. An ion of the same element has a total of 10 electrons. Which statement describes the charge and radius of the ion? (1) The ion is positively charged and its radius is smaller than the radius of the atom. (2) The ion is positively charged and its radius is larger than the radius of the atom. (3) The ion is negatively charged and its radius is smaller than the radius of the atom. (4) The ion is negatively charged and its radius is larger than the radius of the atom. 3 What is the mass number of a carbon atom that contains six protons, eight neutrons, and six electrons? (1) 6 (3) 14 (2) 8 (4) 20 4 Which element is a metalloid? (1) Al (3) As (2) Ar (4) Au 10 Which formula represents a nonpolar molecule? (1) CH4 (3) H2O 5 Which substance can be decomposed by chemical means? (1) aluminum (3) silicon (2) octane (4) xenon (2) HCl 11 The compound XCl is classified as ionic if X represents the element (1) H (3) Rb (2) I (4) Br 6 An element that is malleable and a good conductor of heat and electricity could have an atomic number of (1) 16 (3) 29 (2) 18 (4) 35 12 The chemical bonding in sodium phosphate, Na3PO4, is classified as (1) ionic, only (2) metallic, only (3) both covalent and ionic (4) both covalent and metallic 7 A 1.0-mole sample of krypton gas has a mass of (1) 19 g (3) 39 g (2) 36 g (4) 84 g P.S./Chem.–June ’09 (4) NH3 [2] 13 Which element is composed of molecules that each contain a multiple covalent bond? (1) chlorine (3) hydrogen (2) fluorine (4) nitrogen 20 Compared to the freezing point and boiling point of water at 1 atmosphere, a solution of a salt and water at 1 atmosphere has a (1) lower freezing point and a lower boiling point (2) lower freezing point and a higher boiling point (3) higher freezing point and a lower boiling point (4) higher freezing point and a higher boiling point 14 Which equation represents an exothermic reaction at 298 K? (1) N2(g) + O2(g) → 2NO(g) (2) C(s) + O2(g) → CO2(g) HO 2 (3) KNO3(s) ⎯⎯⎯ → K+(aq) + NO3−(aq) 21 Changes in activation energy during a chemical reaction are represented by a (1) cooling curve (2) heating curve (3) ionization energy diagram (4) potential energy diagram HO 2 (4) NH4Cl(s) ⎯⎯⎯ → NH4+(aq) + Cl−(aq) 15 Standard pressure is equal to (1) 1 atm (3) 273 atm (2) 1 kPa (4) 273 kPa 22 Under which conditions of temperature and pressure would a real gas behave most like an ideal gas? (1) 200. K and 50.0 kPa (2) 200. K and 200.0 kPa (3) 600. K and 50.0 kPa (4) 600. K and 200.0 kPa 16 A large sample of solid calcium sulfate is crushed into smaller pieces for testing. Which two physical properties are the same for both the large sample and one of the smaller pieces? (1) mass and density (2) mass and volume (3) solubility and density (4) solubility and volume 23 Given the equation representing a reaction: 17 According to the kinetic molecular theory, the molecules of an ideal gas (1) have a strong attraction for each other (2) have significant volume (3) move in random, constant, straight-line motion (4) are closely packed in a regular repeating pattern N2O4(g) 2NO2(g) Which statement describes this reaction at equilibrium? (1) The concentration of N2O4(g) must equal the concentration of NO2(g). (2) The concentration of N2O4(g) and the concentration of NO2(g) must be constant. (3) The rate of the forward reaction is greater than the rate of the reverse reaction. (4) The rate of the reverse reaction is greater than the rate of the forward reaction. 18 At 65°C, which compound has a vapor pressure of 58 kilopascals? (1) ethanoic acid (3) propanone (2) ethanol (4) water 24 Which compound is a saturated hydrocarbon? (1) propanal (3) propene (2) propane (4) propyne 19 At STP, which 2.0-gram sample of matter uniformly fills a 340-milliliter closed container? (1) Br2(ᐉ) (3) KCl(aq) (2) Fe(NO3)2(s) (4) Xe(g) P.S./Chem.–June ’09 [3] [OVER] 28 One alternate acid-base theory states that an acid is an (1) H+ donor (3) OH− donor (2) H+ acceptor (4) OH− acceptor 25 The isomers butane and methylpropane differ in their (1) molecular formulas (2) structural formulas (3) total number of atoms per molecule (4) total number of bonds per molecule 29 Which particle has the greatest mass? (1) an alpha particle (3) a neutron (2) a beta particle (4) a positron 26 Which word equation represents a neutralization reaction? (1) base + acid → salt + water (2) base + salt → water + acid (3) salt + acid → base + water (4) salt + water → acid + base 30 A beta particle may be spontaneously emitted from (1) a ground-state electron (2) a stable nucleus (3) an excited electron (4) an unstable nucleus 27 An aqueous solution of lithium hydroxide contains hydroxide ions as the only negative ion in the solution. Lithium hydroxide is classified as an (1) aldehyde (3) Arrhenius acid (2) alcohol (4) Arrhenius base P.S./Chem.–June ’09 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 35 A person with a body temperature of 37°C holds an ice cube with a temperature of 0°C in a room where the air temperature is 20.°C. The direction of heat flow is (1) from the person to the ice, only (2) from the person to the ice and air, and from the air to the ice (3) from the ice to the person, only (4) from the ice to the person and air, and from the air to the person 31 Which electron configuration represents an atom in an excited state? (1) 2–7 (3) 2–8–1 (2) 2–6–2 (4) 2–8–8–2 32 Magnesium and calcium have similar chemical properties because a magnesium atom and a calcium atom have the same (1) atomic number (2) mass number (3) total number of electron shells (4) total number of valence electrons 36 What is the total mass of solute in 1000. grams of a solution having a concentration of 5 parts per million? (1) 0.005 g (3) 0.5 g (2) 0.05 g (4) 5 g 33 What is the empirical formula for a compound with the molecular formula C6H12Cl2O2? (1) CHClO (2) CH2ClO (3) C3H6ClO (4) C6H12Cl2O2 37 Which compound is least soluble in water at 60.°C? (1) KClO3 (3) NaCl (2) KNO3 (4) NH4Cl 34 Given the balanced equation representing a reaction: 4Al(s) + 3O2(g) → 2Al2O3(s) 38 At standard pressure, which element has a freezing point below standard temperature? (1) In (3) Hf (2) Ir (4) Hg Which type of chemical reaction is represented by this equation? (1) (2) (3) (4) double replacement single replacement substitution synthesis P.S./Chem.–June ’09 [5] [OVER] 39 Which two particle diagrams represent mixtures of diatomic elements? Key = atom of one element = atom of another element A C B (1) A and B (2) A and C D (3) B and C (4) B and D 40 The graph below represents the relationship between temperature and time as heat is added to a sample of H2O. Heating Curve for H2O Temperature 200 D 100 –100 C B 0 A Time Which statement correctly describes the energy of the particles of the sample during interval BC? (1) Potential energy decreases and average kinetic energy increases. (2) Potential energy increases and average kinetic energy increases. (3) Potential energy increases and average kinetic energy remains the same. (4) Potential energy remains the same and average kinetic energy increases. 41 Given the balanced equation representing a reaction: 2HCl(aq) + Na2S2O3(aq) → S(s) + H2SO3(aq) + 2NaCl(aq) Decreasing the concentration of Na2S2O3(aq) decreases the rate of reaction because the (1) activation energy decreases (2) activation energy increases (3) frequency of effective collisions decreases (4) frequency of effective collisions increases P.S./Chem.–June ’09 [6] 45 Which reaction occurs spontaneously? (1) Cl2(g) + 2NaBr(aq) → Br2(ᐉ) + 2NaCl(aq) (2) Cl2(g) + 2NaF(aq) → F2(g) + 2NaCl(aq) (3) I2(s) + 2NaBr(aq) → Br2(ᐉ) + 2NaI(aq) (4) I2(s) + 2NaF(aq) → F2(g) + 2NaI(aq) 42 Given the equation representing a reaction at equilibrium: H2(g) + I2(g) + heat 2HI(g) Which change favors the reverse reaction? (1) (2) (3) (4) decreasing the concentration of HI(g) decreasing the temperature increasing the concentration of I2(g) increasing the pressure 46 Which sample of HCl(aq) contains the greatest number of moles of solute particles? (1) 1.0 L of 2.0 M HCl(aq) (2) 2.0 L of 2.0 M HCl(aq) (3) 3.0 L of 0.50 M HCl(aq) (4) 4.0 L of 0.50 M HCl(aq) 43 Which formula represents 2-butene? H H H H H H C C C C H H H H H H H H H H H (1) H H H (3) H C C C C H H H H H (2) 47 Which change in pH represents a hundredfold increase in the concentration of hydronium ions in a solution? (1) pH 1 to pH 2 (3) pH 2 to pH 1 (2) pH 1 to pH 3 (4) pH 3 to pH 1 C C C C H 48 Which indicator would best distinguish between a solution with a pH of 3.5 and a solution with a pH of 5.5? (1) bromthymol blue (3) litmus (2) bromcresol green (4) thymol blue C C C C H H H H H (4) 49 Given the equation: 44 Given the balanced equation representing a reaction: HCl(g) + H2O(ᐉ) → X(aq) + Cl−(aq) Fe2O3 + 2Al → Al2O3 + 2Fe Which ion is represented by X? (1) hydroxide (3) hypochlorite (2) hydronium (4) perchlorate During this reaction, the oxidation number of Fe changes from (1) (2) (3) (4) +2 to 0 as electrons are transferred +2 to 0 as protons are transferred +3 to 0 as electrons are transferred +3 to 0 as protons are transferred P.S./Chem.–June ’09 50 Which nuclide is used to investigate human thyroid gland disorders? (1) carbon-14 (3) cobalt-60 (2) potassium-37 (4) iodine-131 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 51 through 53 on the information below. A sample of helium gas is in a closed system with a movable piston. The volume of the gas sample is changed when both the temperature and the pressure of the sample are increased. The table below shows the initial temperature, pressure, and volume of the gas sample, as well as the final temperature and pressure of the sample. Helium Gas in a Closed System Temperature (K) Pressure (atm) Volume (mL) initial 200. 2.0 500. final 300. 7.0 ? Condition 51 In the space in your answer booklet, show a correct numerical setup for calculating the final volume of the helium gas sample. [1] 52 Convert the final temperature of the helium gas sample to degrees Celsius. [1] 53 Compare the total number of gas particles in the sample under the initial conditions to the total number of gas particles in the sample under the final conditions. [1] P.S./Chem.–June ’09 [8] Base your answers to questions 54 through 57 on the information below. Molar Mass and Boiling Point of Four Substances Substance Molar Mass Boiling Point (g/mol) at 1 atm (K) methane 16. 112 ethane 30. 185 propane 44. 231 butane 58. 273 54 On the grid in your answer booklet, mark an appropriate scale on the axis labeled “Boiling Point (K).” [1] 55 On the same grid, plot the data from the data table. Circle and connect the points. [1] 56 Based on the data in the table, state the relationship between the boiling point at 1 atmosphere and molar mass for these four substances. [1] 57 State, in terms of intermolecular forces, why the boiling point of propane at 1 atmosphere is lower than the boiling point of butane at 1 atmosphere. [1] Base your answers to questions 58 and 59 on the information below. At a pressure of 101.3 kilopascals and a temperature of 373 K, heat is removed from a sample of water vapor, causing the sample to change from the gaseous phase to the liquid phase. This phase change is represented by the equation below. H2O(g) → H2O(ᐉ) + heat 58 Explain, in terms of particle arrangement, why entropy decreases during this phase change. [1] 59 Determine the total amount of heat released by 5.00 grams of water vapor during this phase change. [1] P.S./Chem.–June ’09 [9] [OVER] Base your answers to questions 60 through 62 on the information below. A voltaic cell with magnesium and copper electrodes is shown in the diagram below. The copper electrode has a mass of 15.0 grams. Voltaic Cell V Wire Switch Voltmeter Salt bridge Mg(s) electrode Mg2+(aq) Mg(s) + Cu2+(aq) Cu(s) electrode Cu2+(aq) Mg2+(aq) + Cu(s) When the switch is closed, the reaction in the cell begins. The balanced ionic equation for the reaction in the cell is shown below the cell diagram. After several hours, the copper electrode is removed, rinsed with water, and dried. At this time, the mass of the copper electrode is greater than 15.0 grams. 60 State the direction of electron flow through the wire between the electrodes when the switch is closed. [1] 61 State the purpose of the salt bridge in this cell. [1] 62 Explain, in terms of copper ions and copper atoms, why the mass of the copper electrode increases as the cell operates. Your response must include information about both copper ions and copper atoms. [1] P.S./Chem.–June ’09 [10] Base your answers to questions 63 through 65 on the information below. Naturally Occurring Isotopes of Sulfur Isotope Atomic Mass (atomic mass units, u) Natural Abundance (%) 32S 31.97 94.93 33S 32.97 0.76 34S 33.97 4.29 36S 35.97 0.02 63 State, in terms of the number of subatomic particles, one similarity and one difference between the atoms of these isotopes of sulfur. [1] 64 In the space in your answer booklet, draw a Lewis electron-dot diagram for an atom of sulfur-33. [1] 65 In the space in your answer booklet, show a correct numerical setup for calculating the atomic mass of sulfur. [1] P.S./Chem.–June. ’09 [11] [OVER] Part C Answer all questions in this part. Directions (66–83): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 66 and 67 on the information below. In 1897, J. J. Thomson demonstrated in an experiment that cathode rays were deflected by an electric field. This suggested that cathode rays were composed of negatively charged particles found in all atoms. Thomson concluded that the atom was a positively charged sphere of almost uniform density in which negatively charged particles were embedded. The total negative charge in the atom was balanced by the positive charge, making the atom electrically neutral. In the early 1900s, Ernest Rutherford bombarded a very thin sheet of gold foil with alpha particles. After interpreting the results of the gold foil experiment, Rutherford proposed a more sophisticated model of the atom. 66 State one conclusion from Rutherford’s experiment that contradicts one conclusion made by Thomson. [1] 67 State one aspect of the modern model of the atom that agrees with a conclusion made by Thomson. [1] Base your answers to questions 68 through 70 on the information below. Cobalt-60 is commonly used as a source of radiation for the prevention of food spoilage. Bombarding cobalt-59 nuclei with neutrons produces the nuclide cobalt-60. A food irradiation facility replaces the cobalt-60, a source of gamma rays, when the radioactivity 1 level falls to 8 of its initial level. The nuclide cesium-137 is also a source of radiation for the prevention of food spoilage. 68 Identify one emission spontaneously released by a cobalt-60 nucleus. [1] 69 Determine the total number of years that elapse before an original cobalt-60 source in an irradiation facility must be replaced. [1] 70 Complete the nuclear equation in your answer booklet for the decay of cesium-137. Your response must include the symbol, atomic number, and mass number of the missing particle. [1] P.S./Chem.–June ’09 [12] Base your answers to questions 71 through 73 on the information below. A soft-drink bottling plant makes a colorless, slightly acidic carbonated beverage called soda water. During production of the beverage, CO2(g) is dissolved in water at a pressure greater than 1 atmosphere. The bottle containing the solution is capped to maintain that pressure above the solution. As soon as the bottle is opened, fizzing occurs due to CO2(g) being released from the solution. 71 Explain why CO2(g) is released when a bottle of soda water is opened. [1] 72 Write the chemical name of the acid in soda water. [1] 73 State the relationship between the solubility of CO2(g) in water and the temperature of the aqueous solution. [1] Base your answers to questions 74 through 76 on the information below. During a bread-making process, glucose is converted to ethanol and carbon dioxide, causing the bread dough to rise. Zymase, an enzyme produced by yeast, is a catalyst needed for this reaction. 74 Balance the equation in your answer booklet for the reaction that causes bread dough to rise, using the smallest whole-number coefficients. [1] 75 In the space in your answer booklet, draw a structural formula for the alcohol formed in this reaction. [1] 76 State the effect of zymase on the activation energy for this reaction. [1] P.S./Chem.–June ’09 [13] [OVER] Base your answers to questions 77 and 78 on the information below. In performing a titration, a student adds three drops of phenolphthalein to a flask containing 25.00 milliliters of HCl(aq). Using a buret, the student slowly adds 0.150 M NaOH(aq) to the flask until one drop causes the indicator to turn light pink. The student determines that a total volume of 20.20 milliliters of NaOH(aq) was used in this titration. 77 The concentration of the NaOH(aq) used in the titration is expressed to what number of significant figures? [1] 78 Calculate the molarity of the HCl(aq) used in this titration. Your response must include both a correct numerical setup and the calculated result. [2] Base your answers to questions 79 through 83 on the information below. Arsenic is often obtained by heating the ore arsenopyrite, FeAsS. The decomposition of FeAsS is represented by the balanced equation below. heat → FeS(s) + As(g) FeAsS(s) ⎯⎯⎯ In the solid phase, arsenic occurs in two forms. One form, yellow arsenic, has a density of 1.97 g/cm3 at STP. The other form, gray arsenic, has a density of 5.78 g/cm3 at STP. When arsenic is heated rapidly in air, arsenic(III) oxide is formed. Although arsenic is toxic, it is needed by the human body in very small amounts. The body of a healthy human adult contains approximately 5 milligrams of arsenic. 79 Convert the mass of arsenic found in the body of a healthy human adult to grams. [1] 80 When heated, a 125.0-kilogram sample of arsenopyrite yields 67.5 kilograms of FeS. Determine the total mass of arsenic produced in this reaction. [1] 81 Write the formula for the compound produced when arsenic is heated rapidly in air. [1] 82 Explain, in terms of the arrangement of atoms, why the two forms of arsenic have different densities at STP. [1] 83 Calculate the percent composition by mass of arsenic in arsenopyrite. Your response must include both a correct numerical setup and the calculated result. [2] P.S./Chem.–June ’09 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Wednesday, June 17, 2009 — 1:15 to 4:15 p.m., only ANSWER SHEET I Male I Female Grade . . . . . . . . . . . . Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below should be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 17, 2009 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . For Raters Only 51 51 52 °C 52 53 53 For Raters Only 54 and 55 Boiling Point (K) Boiling Point at 1 atm Versus Molar Mass 54 55 0 10. 20. 30. 40. 50. 60. Molar Mass (g/mol) 56 56 57 57 [2] For Raters Only 58 58 59 59 J 60 60 61 61 62 62 [3] [OVER] For Raters Only 63 Similarity: 63 Difference: 64 64 65 65 Total Score for Part B–2 [4] For Raters Only Part C 66 66 67 67 68 68 69 70 69 y 137Cs 55 → −10 e + ________ 70 71 71 72 72 73 73 [5] [OVER] For Raters Only zymase 74 ________ C6H12O6 ⎯⎯⎯→ ________ C2H5OH + ________ CO2 + energy 74 75 75 76 76 77 77 78 78 M [6] For Raters Only 79 g 79 80 kg 80 81 81 82 82 83 83 % Total Score for Part C [7] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, August 13, 2009 — 12:30 to 3:30 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 Which statement describes a chemical property of bromine? (1) Bromine is soluble in water. (2) Bromine has a reddish-brown color. (3) Bromine combines with aluminum to produce AlBr3. (4) Bromine changes from a liquid to a gas at 332 K and 1 atm. 1 Which particle has the least mass? (3) 10n (1) 42He (2) 11H (4) −10e 2 What information is necessary to determine the atomic mass of the element chlorine? (1) the atomic mass of each artificially produced isotope of chlorine, only (2) the relative abundance of each naturally occurring isotope of chlorine, only (3) the atomic mass and the relative abundance of each naturally occurring isotope of chlorine (4) the atomic mass and the relative abundance of each naturally occurring and artificially produced isotope of chlorine 7 An atom of aluminum in the ground state and an atom of gallium in the ground state have the same (1) mass (2) electronegativity (3) total number of protons (4) total number of valence electrons 3 In an atom of argon-40, the number of protons (1) equals the number of electrons (2) equals the number of neutrons (3) is less than the number of electrons (4) is greater than the number of electrons 8 Which type of matter is composed of two or more elements that are chemically combined in a fixed proportion? (1) solution (2) compound (3) homogeneous mixture (4) heterogeneous mixture 4 An electron in a sodium atom moves from the third shell to the fourth shell. This change is a result of the atom (1) absorbing energy (3) gaining an electron (2) releasing energy (4) losing an electron 9 Which type of substance can conduct electricity in the liquid phase but not in the solid phase? (1) ionic compound (2) molecular compound (3) metallic element (4) nonmetallic element 5 Which statement describes oxygen gas, O2(g), and ozone gas, O3(g)? (1) They have different molecular structures, only. (2) They have different properties, only. (3) They have different molecular structures and different properties. (4) They have the same molecular structure and the same properties. P.S./Chem.–Aug. ’09 10 Why is a molecule of CO2 nonpolar even though the bonds between the carbon atom and the oxygen atoms are polar? (1) The shape of the CO2 molecule is symmetrical. (2) The shape of the CO2 molecule is asymmetrical. (3) The CO2 molecule has a deficiency of electrons. (4) The CO2 molecule has an excess of electrons. [2] 19 How do the boiling point and freezing point of a solution of water and calcium chloride at standard pressure compare to the boiling point and freezing point of water at standard pressure? (1) Both the freezing point and boiling point of the solution are higher. (2) Both the freezing point and boiling point of the solution are lower. (3) The freezing point of the solution is higher and the boiling point of the solution is lower. (4) The freezing point of the solution is lower and the boiling point of the solution is higher. 11 Which formula represents a molecular compound? (1) HI (3) KCl (2) KI (4) LiCl 12 Which element has the greatest density at STP? (1) scandium (3) silicon (2) selenium (4) sodium 13 Particles are arranged in a crystal structure in a sample of (3) Ar(g) (1) H2(g) (2) Br2(ᐉ) (4) Ag(s) 20 Under which conditions of temperature and pressure does a sample of neon behave most like an ideal gas? (1) 100 K and 0.25 atm (2) 100 K and 25 atm (3) 400 K and 0.25 atm (4) 400 K and 25 atm 14 The relatively high boiling point of water is due to water having (1) hydrogen bonding (2) metallic bonding (3) nonpolar covalent bonding (4) strong ionic bonding 15 Matter is classified as a (1) substance, only (2) substance or as a mixture of substances (3) homogenous mixture, only (4) homogenous mixture or as a heterogeneous mixture 21 According to the kinetic molecular theory, which statement describes the particles in a sample of an ideal gas? (1) The force of attraction between the gas particles is strong. (2) The motion of the gas particles is random and straight-line. (3) The collisions between the gas particles cannot result in a transfer of energy between the particles. (4) The separation between the gas particles is smaller than the size of the gas particles themselves. 16 Which substance can not be decomposed by a chemical change? (1) ammonia (3) propanol (2) copper (4) water 17 A beaker contains both alcohol and water. These liquids can be separated by distillation because the liquids have different (1) boiling points (3) particle sizes (2) densities (4) solubilities 22 The activation energy of a chemical reaction can be decreased by the addition of (1) a catalyst (3) electrical energy (2) an indicator (4) thermal energy 18 Which term is defined as a measure of the average kinetic energy of the particles in a sample of matter? (1) activation energy (3) temperature (2) potential energy (4) entropy P.S./Chem.–Aug. ’09 23 A straight-chain hydrocarbon that has only one double bond in each molecule has the general formula (1) CnH2n−6 (3) CnH2n (2) CnH2n−2 (4) CnH2n+2 [3] [OVER] 24 Why can an increase in temperature lead to more effective collisions between reactant particles and an increase in the rate of a chemical reaction? (1) The activation energy of the reaction increases. (2) The activation energy of the reaction decreases. (3) The number of molecules with sufficient energy to react increases. (4) The number of molecules with sufficient energy to react decreases. 27 Which substance is an electrolyte? (3) HCl (1) CCl4 (2) C2H6 (4) H2O 28 One acid-base theory defines a base as an (3) H donor (1) H+ donor (2) H+ acceptor (4) H acceptor 29 A change in the nucleus of an atom that converts the atom from one element to another element is called (1) combustion (3) polymerization (2) neutralization (4) transmutation 25 Which reaction results in the production of soap? (1) esterification (3) polymerization (2) fermentation (4) saponification 30 Which particle is emitted from a hydrogen-3 nucleus when it undergoes radioactive decay? (1) α (3) β+ − (2) β (4) γ 26 Which substance is always a product when an Arrhenius acid in an aqueous solution reacts with an Arrhenius base in an aqueous solution? (1) HBr (3) KBr (2) H2O (4) KOH P.S./Chem.–Aug. ’09 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 Which electron configuration represents an excited state for a potassium atom? (1) 2-8-7-1 (3) 2-8-8-1 (2) 2-8-7-2 (4) 2-8-8-2 37 Which formula represents strontium phosphate? (3) Sr2(PO4)3 (1) SrPO4 (2) Sr3PO8 (4) Sr3(PO4)2 38 Which Lewis electron-dot diagram represents calcium oxide? 32 A sample of an element is malleable and can conduct electricity. This element could be (1) H (3) S (2) He (4) Sn 2+ Ca O Ca (1) 33 Which general trend is demonstrated by the Group 17 elements as they are considered in order from top to bottom on the Periodic Table? (1) a decrease in atomic radius (2) a decrease in electronegativity (3) an increase in first ionization energy (4) an increase in nonmetallic behavior (2) 35 Which equation represents a decomposition reaction? CaCO3(s) → CaO(s) + CO2(g) Cu(s) + 2AgNO3(aq) → 2Ag(s) + Cu(NO3)2(aq) 2H2(g) + O2(g) → 2H2O(ᐉ) KOH(aq) + HCl(aq) → KCl(aq) + H2O(ᐉ) 2– O (4) 40 What is the mass of NH4Cl that must dissolve in 200. grams of water at 50.°C to make a saturated solution? (1) 26 g (3) 84 g (2) 42 g (4) 104 g 36 A compound has the empirical formula CH2O and a gram-formula mass of 60. grams per mole. What is the molecular formula of this compound? (1) CH2O (3) C3H8O (2) C2H4O2 (4) C4H8O4 P.S./Chem.–Aug. ’09 Ca 39 Which statement describes the transfer of heat energy that occurs when an ice cube is added to an insulated container with 100 milliliters of water at 25°C? (1) Both the ice cube and the water lose heat energy. (2) Both the ice cube and the water gain heat energy. (3) The ice cube gains heat energy and the water loses heat energy. (4) The ice cube loses heat energy and the water gains heat energy. 34 Which element is a liquid at 758 K and standard pressure? (1) gold (3) platinum (2) silver (4) thallium (1) (2) (3) (4) (3) 2+ Ca O 2– O [5] [OVER] 41 Given the bright-line spectra of three elements and the spectrum of a mixture formed from at least two of these elements: Bright-Line Spectra Element D Element E Element G Mixture 750 nm 360 nm Which elements are present in this mixture? (1) E and D, only (2) E and G, only (3) D and G, only (4) D, E, and G 42 Given the balanced particle-diagram equation: Key = an atom of an element = an atom of a different element + Which statement describes the type of change and the chemical properties product and reactants? (1) The equation represents a physical change, with the product and reactants different chemical properties. (2) The equation represents a physical change, with the product and reactants identical chemical properties. (3) The equation represents a chemical change, with the product and reactants different chemical properties. (4) The equation represents a chemical change, with the product and reactants identical chemical properties. P.S./Chem.–Aug. ’09 [6] of the having having having having 47 Which formula represents an unsaturated hydrocarbon? 43 Which quantity of heat is equal to 200. joules? (1) 20.0 kJ (3) 0.200 kJ (2) 2.00 kJ (4) 0.0200 kJ H H H H (1) (3) Volume Volume (2) (4) H H C C H (1) (3) H H H H C C H H C C OH H H H H (2) (4) 48 What is the oxidation state of nitrogen in the compound NH4Br? (1) –1 (3) –3 (2) +2 (4) +4 Pressure Volume Pressure Volume C C H Pressure Pressure 44 Which graph represents the relationship between pressure and volume for a sample of an ideal gas at constant temperature? H O 49 A student completes a titration by adding 12.0 milliliters of NaOH(aq) of unknown concentration to 16.0 milliliters of 0.15 M HCl(aq). What is the molar concentration of the NaOH(aq)? (1) 0.11 M (3) 1.1 M (2) 0.20 M (4) 5.0 M 50 What is the half-life of a radioisotope if 25.0 grams of an original 200.-gram sample of the isotope remains unchanged after 11.46 days? (1) 2.87 d (3) 11.46 d (2) 3.82 d (4) 34.38 d 45 The entropy of a sample of H2O increases as the sample changes from a (1) gas to a liquid (3) liquid to a gas (2) gas to a solid (4) liquid to a solid 46 Ethanol and dimethyl ether have different chemical and physical properties because they have different (1) functional groups (2) molecular masses (3) numbers of covalent bonds (4) percent compositions by mass P.S./Chem.–Aug. ’09 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–63): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 Identify the element in Period 3 of the Periodic Table that reacts with oxygen to form an ionic compound represented by the formula X2O. [1] 52 Given the balanced equation representing a reaction: 2C2H6 + 7O2 → 4CO2 + 6H2O Determine the total number of moles of oxygen that react completely with 8.0 moles of C2H6. [1] 53 On the potential energy diagram in your answer booklet, draw an arrow to represent the activation energy of the forward reaction. [1] 54 Describe the electrons in an atom of carbon in the ground state. Your response must include: • the charge of an electron [1] • the location of electrons based on the wave-mechanical model [1] • the total number of electrons in a carbon atom [1] 55 Determine the mass of 5.20 moles of C6H12 (gram-formula mass = 84.2 grams/mole). [1] Base your answers to questions 56 through 58 on the information below. A 1.0-gram strip of zinc is reacted with hydrochloric acid in a test tube. The unbalanced equation below represents the reaction. Zn(s) + HCl(aq) → H2(g) + ZnCl2(aq) 56 Balance the equation in your answer booklet for the reaction of zinc and hydrochloric acid, using the smallest whole-number coefficients. [1] 57 Explain, using information from Reference Table F, why the symbol (aq) is used to describe the product ZnCl2. [1] 58 Explain, in terms of collision theory, why using 1.0 gram of powdered zinc, instead of the 1.0-gram strip of zinc, would have increased the rate of the reaction. [1] P.S./Chem.–Aug. ’09 [8] Base your answers to questions 59 through 63 on the information below. Bond energy is the amount of energy required to break a chemical bond. The table below gives a formula and the carbon-nitrogen bond energy for selected nitrogen compounds. Selected Nitrogen Compounds Compound Formula Carbon-Nitrogen Bond Energy (kJ/mol) hydrogen cyanide H C N 890. H N C O 615 isocyanic acid H methanamine H C N H 293 H H 59 Describe, in terms of electrons, the type of bonding between the carbon atom and the nitrogen atom in a molecule of methanamine. [1] 60 Identify the noble gas that has atoms in the ground state with the same electron configuration as the nitrogen in a molecule of isocyanic acid. [1] 61 State the relationship between the number of electrons in a carbon-nitrogen bond and carbon-nitrogen bond energy. [1] 62 Explain, in terms of charge distribution, why a molecule of hydrogen cyanide is polar. [1] 63 A 3.2-gram sample of air contains 0.000 74 gram of hydrogen cyanide. Determine the concentration, in parts per million, of the hydrogen cyanide in this sample. [1] P.S./Chem.–Aug. ’09 [9] [OVER] Part C Answer all questions in this part. Directions (64–81): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 64 Based on data collected during a laboratory investigation, a student determined an experimental value of 322 joules per gram for the heat of fusion of H2O. Calculate the student’s percent error. Your response must include a correct numerical setup and the calculated result. [2] Base your answers to questions 65 through 67 on the information below. A student used blue litmus paper and phenolphthalein paper as indicators to test the pH of distilled water and five aqueous household solutions. Then the student used a pH meter to measure the pH of the distilled water and each solution. The results of the student’s work are recorded in the table below. Testing Results Liquid Tested Color of Blue Litmus Paper Color of Measured pH Phenolphthalein Value Using a Paper pH Meter 2% milk blue colorless 6.4 distilled water blue colorless 7.0 household ammonia blue pink 11.5 lemon juice red colorless 2.3 tomato juice red colorless 4.3 vinegar red colorless 3.3 65 Identify the liquid tested that has the lowest hydronium ion concentration. [1] 66 Explain, in terms of the pH range for color change on Reference Table M, why litmus is not appropriate to differentiate the acidity levels of tomato juice and vinegar. [1] 67 Based on the measured pH values, identify the liquid tested that is 10 times more acidic than vinegar. [1] P.S./Chem.–Aug. ’09 [10] Base your answers to questions 68 through 72 on the information below. Biodiesel is an alternative fuel for vehicles that use petroleum diesel. Biodiesel is produced by reacting vegetable oil with CH3OH. Methyl palmitate, C15H31COOCH3, a compound found in biodiesel, is made from soybean oil. One reaction of methyl palmitate with oxygen is represented by the balanced equation below. 2C15H31COOCH3 + 49O2 → 34CO2 + 34H2O + energy 68 Write an IUPAC name for the compound that reacts with vegetable oil to produce biodiesel. [1] 69 Explain, in terms of both atoms and molecular structure, why there is no isomer of CH3OH. [1] 70 Identify the class of organic compounds to which methyl palmitate belongs. [1] 71 Identify the type of organic reaction represented by the balanced equation. [1] 72 State evidence from the balanced equation that indicates the reaction is exothermic. [1] Base your answers to questions 73 through 76 on the information below. In a laboratory investigation, a student constructs a voltaic cell with iron and copper electrodes. Another student constructs a voltaic cell with zinc and iron electrodes. Testing the cells during operation enables the students to write the balanced ionic equations below. Cell with iron and copper electrodes: Cu2+(aq) + Fe(s) → Cu(s) + Fe2+(aq) Cell with zinc and iron electrodes: Fe2+(aq) + Zn(s) → Fe(s) + Zn2+(aq) 73 State evidence from the balanced equation for the cell with iron and copper electrodes that indicates the reaction in the cell is an oxidation-reduction reaction. [1] 74 Identify the particles transferred between Fe2+ and Zn during the reaction in the cell with zinc and iron electrodes. [1] 75 Write a balanced half-reaction equation for the reduction that takes place in the cell with zinc and iron electrodes. [1] 76 State the relative activity of the three metals used in these two voltaic cells. [1] P.S./Chem.–Aug. ’09 [11] [OVER] Base your answers to questions 77 through 79 on the information below. A method used by ancient Egyptians to obtain copper metal from copper(I) sulfide ore was heating the ore in the presence of air. Later, copper was mixed with tin to produce a useful alloy called bronze. 77 Calculate the density of a 129.5-gram sample of bronze that has a volume of 14.8 cubic centimeters. Your response must include a correct numerical setup and the calculated result. [2] 78 Convert the melting point of the metal obtained from copper(I) sulfide ore to degrees Celsius. [1] 79 A 133.8-gram sample of bronze was 10.3% tin by mass. Determine the total mass of tin in the sample. [1] Base your answers to questions 80 and 81 on the information below. Scientists are investigating the production of energy using hydrogen-2 nuclei (deuterons) and hydrogen-3 nuclei (tritons). The balanced equation below represents one nuclear reaction between two deuterons. 2H 1 + 21 H → 32 He + 10 n + 5.23 × 10−13 J 80 State, in terms of subatomic particles, how a deuteron differs from a triton. [1] 81 Identify the type of nuclear reaction represented by the equation. [1] P.S./Chem.–Aug. ’09 [12] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, August 13, 2009 — 12:30 to 3:30 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . For Raters Only 51 __________________________________ 51 52 52 mol Potential Energy 53 53 Reaction Coordinate For Raters Only 54 54 55 g 55 56 ________ Zn(s) + ________ HCl(aq) → ________ H2(g) + ________ ZnCl2(aq) 56 57 57 58 58 [2] For Raters Only 59 59 60 __________________________________ 60 61 61 62 62 63 ppm 63 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 64 64 % 65 65 66 66 67 67 [4] For Raters Only 68 68 69 69 70 70 71 71 72 72 73 73 74 74 75 75 76 76 [5] [OVER] For Raters Only 77 77 g/cm3 78 °C 78 79 g 79 80 80 81 81 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 28, 2010 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. Your answer sheet for Part A and Part B–1 is the last page of this examination booklet. Turn to the last page and fold it along the perforations. Then, slowly and carefully, tear off your answer sheet and fill in the heading. The answers to the questions in Part B–2 and Part C are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. Record the number of your choice for each Part A and Part B–1 multiple-choice question on your separate answer sheet. Write your answers to the Part B–2 and Part C questions in your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers on your separate answer sheet and in your answer booklet. When you have completed the examination, you must sign the statement printed at the end of your separate answer sheet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer sheet and answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 Which element has an atom in the ground state with a total of three valence electrons? (1) aluminum (3) phosphorus (2) lithium (4) scandium 1 Which two particles have opposite charges? (1) an electron and a neutron (2) an electron and a proton (3) a proton and a neutron (4) a proton and a positron 8 Which substance can be broken down by chemical means? (1) magnesium (3) mercury (2) manganese (4) methanol 2 Which statement describes how an atom in the ground state becomes excited? (1) The atom absorbs energy, and one or more electrons move to a higher electron shell. (2) The atom absorbs energy, and one or more electrons move to a lower electron shell. (3) The atom releases energy, and one or more electrons move to a higher electron shell. (4) The atom releases energy, and one or more electrons move to a lower electron shell. 9 The gram-formula mass of NO2 is defined as the mass of (1) one mole of NO2 (2) one molecule of NO2 (3) two moles of NO (4) two molecules of NO 3 An element that has a low first ionization energy and good conductivity of heat and electricity is classified as a (1) metal (3) nonmetal (2) metalloid (4) noble gas 10 In which type of reaction do two or more substances combine to produce a single substance? (1) synthesis (2) decomposition (3) single replacement (4) double replacement 4 The chemical properties of calcium are most similar to the chemical properties of (1) Ar (3) Mg (2) K (4) Sc 11 Which formula represents a nonpolar molecule? (1) HCl (3) NH3 (2) H2O (4) CH4 5 Which element is a liquid at STP? (1) argon (3) chlorine (2) bromine (4) sulfur 12 Which symbol represents an atom in the ground state with the most stable valence electron configuration? (1) B (3) Li (2) O (4) Ne 6 Which statement describes a chemical property of aluminum? (1) Aluminum is malleable. (2) Aluminum reacts with sulfuric acid. (3) Aluminum conducts an electric current. (4) Aluminum has a density of 2.698 g/cm3 at STP. P.S./Chem.–Jan. ’10 13 Which element has an atom with the greatest tendency to attract electrons in a chemical bond? (1) carbon (3) silicon (2) chlorine (4) sulfur [2] 20 Which type of energy is associated with the random motion of the particles in a sample of gas? (1) chemical energy (2) electromagnetic energy (3) nuclear energy (4) thermal energy 14 The nitrogen atoms in a molecule of N2 share a total of (1) one pair of electrons (2) one pair of protons (3) three pairs of electrons (4) three pairs of protons 15 An ionic compound is formed when there is a reaction between the elements (1) strontium and chlorine (2) hydrogen and chlorine (3) nitrogen and oxygen (4) sulfur and oxygen 21 The particles in which sample of LiCl(s) have the same average kinetic energy as the particles in a 2.0-mole sample of H2O(ᐉ) at 25°C? (1) 1.0 mol at 75°C (2) 2.0 mol at 50.°C (3) 3.0 mol at 25°C (4) 4.0 mol at 0°C 16 Which compound has both ionic and covalent bonding? (1) CaCO3 (3) CH3OH (2) CH2Cl2 (4) C6H12O6 22 Which rigid cylinder contains the same number of gas molecules at STP as a 2.0-liter rigid cylinder containing H2(g) at STP? (1) 1.0-L cylinder of O2(g) (2) 2.0-L cylinder of CH4(g) (3) 1.5-L cylinder of NH3(g) (4) 4.0-L cylinder of He(g) 17 The liquids hexane and water are placed in a test tube. The test tube is stoppered, shaken, and placed in a test tube rack. The liquids separate into two distinct layers because hexane and water have different (1) formula masses (2) molecular polarities (3) pH values (4) specific heats 23 Hydrogen bonding is a type of (1) strong covalent bond (2) weak ionic bond (3) strong intermolecular force (4) weak intermolecular force 18 Which statement describes the particles of an ideal gas based on the kinetic molecular theory? (1) The gas particles are relatively far apart and have negligible volume. (2) The gas particles are in constant, nonlinear motion. (3) The gas particles have attractive forces between them. (4) The gas particles have collisions without transferring energy. 24 The data collected from a laboratory titration are used to calculate the (1) rate of a chemical reaction (2) heat of a chemical reaction (3) concentration of a solution (4) boiling point of a solution 25 When one compound dissolves in water, the only positive ion produced in the solution is H3O+(aq). This compound is classified as (1) a salt (2) a hydrocarbon (3) an Arrhenius acid (4) an Arrhenius base 19 Under which conditions of temperature and pressure would a 1-liter sample of a real gas behave most like an ideal gas? (1) 100 K and 0.1 atm (2) 100 K and 10 atm (3) 500 K and 0.1 atm (4) 500 K and 10 atm P.S./Chem.–Jan. ’10 [3] [OVER] 26 Which nuclear emission has the greatest mass and the least penetrating power? (1) an alpha particle (3) a neutron (2) a beta particle (4) a positron 29 For which compound is the process of dissolving in water exothermic? (1) NaCl (3) NH4Cl (2) NaOH (4) NH4NO3 27 Which radioisotope has an atom that emits a particle with a mass number of 0 and a charge of +1? (1) 3H (3) 19Ne 16 (2) N (4) 239Pu 30 Which quantities must be equal for a chemical reaction at equilibrium? (1) the activation energies of the forward and reverse reactions (2) the rates of the forward and reverse reactions (3) the concentrations of the reactants and products (4) the potential energies of the reactants and products 28 In which type of reaction do two lighter nuclei combine to form one heavier nucleus? (1) combustion (3) nuclear fission (2) reduction (4) nuclear fusion P.S./Chem.–Jan. ’10 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write on the separate answer sheet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 36 Given the balanced equation representing a reaction: 31 Which formula represents copper(I) oxide? (1) CuO (3) Cu2O (2) CuO2 (4) Cu2O2 CaO(s) + CO2(g) → CaCO3(s) + heat 32 At STP, a 7.49-gram sample of an element has a volume of 1.65 cubic centimeters. The sample is most likely (1) Ta (3) Te (2) Tc (4) Ti What is the total mass of CaO(s) that reacts completely with 88 grams of CO2(g) to produce 200. grams of CaCO3(s)? 33 Which element, represented by X, reacts with fluorine to produce the compound XF2? (1) aluminum (3) magnesium (2) argon (4) sodium 37 What is the empirical formula of a compound that has a carbon-to-hydrogen ratio of 2 to 6? (1) 56 g (2) 88 g (1) CH3 (2) C2H6 34 Each diagram below represents the nucleus of a different atom. 1p D 1p 1n 1p 2n 2p 2n E Q R H2(g) + Cl2(g) → 2HCl(g) + energy Which statement describes the energy changes in this reaction? (1) Energy is absorbed as bonds are formed, only. (2) Energy is released as bonds are broken, only. (3) Energy is absorbed as bonds are broken, and energy is released as bonds are formed. (4) Energy is absorbed as bonds are formed, and energy is released as bonds are broken. (3) Q and R, only (4) Q, R, and E 35 As atomic number increases within Group 15 on the Periodic Table, atomic radius (1) decreases, only (2) increases, only (3) decreases, then increases (4) increases, then decreases P.S./Chem.–Jan. ’10 (3) C3H (4) C6H2 38 Given the balanced equation representing a reaction: Which diagrams represent nuclei of the same element? (1) D and E, only (2) D, E, and Q (3) 112 g (4) 288 g 39 Which solution has the highest boiling point at standard pressure? (1) 0.10 M KCl(aq) (2) 0.10 M K2SO4(aq) (3) 0.10 M K3PO4(aq) (4) 0.10 M KNO3(aq) [5] [OVER] 45 In a biochemical reaction, an enzyme acts as a catalyst, causing the (1) activation energy of the reaction to decrease (2) potential energy of the reactants to decrease (3) kinetic energy of the reactants to increase (4) heat of reaction to increase 40 What is the molarity of 1.5 liters of an aqueous solution that contains 52 grams of lithium fluoride, LiF, (gram-formula mass = 26 grams/mole)? (1) 1.3 M (3) 3.0 M (2) 2.0 M (4) 0.75 M 41 What occurs when a 35-gram aluminum cube at 100.°C is placed in 90. grams of water at 25°C in an insulated cup? (1) Heat is transferred from the aluminum to the water, and the temperature of the water decreases. (2) Heat is transferred from the aluminum to the water, and the temperature of the water increases. (3) Heat is transferred from the water to the aluminum, and the temperature of the water decreases. (4) Heat is transferred from the water to the aluminum, and the temperature of the water increases. 46 Given the formula for an organic compound: H H H H O C C C C H H H H C OH This compound is classified as an (1) aldehyde (2) amine (3) ester (4) organic acid 47 Butanal and butanone have different chemical and physical properties primarily because of differences in their (1) functional groups (2) molecular masses (3) molecular formulas (4) number of carbon atoms per molecule 42 Which temperature is equal to 120. K? (1) −153°C (3) +293°C (2) −120.°C (4) +393°C 43 A rigid cylinder contains a sample of gas at STP. What is the pressure of this gas after the sample is heated to 410 K? (1) 1.0 atm (3) 0.67 atm (2) 0.50 atm (4) 1.5 atm 48 Which salt is produced when sulfuric acid and calcium hydroxide react completely? (1) CaH2 (3) CaS (2) CaO (4) CaSO4 49 Which radioisotope is used to treat thyroid disorders? (1) Co-60 (3) C-14 (2) I-131 (4) U-238 44 Given the balanced equation representing a phase change: C6H4Cl2(s) + energy → C6H4Cl2(g) Which statement describes this change? (1) It is endothermic, and entropy decreases. (2) It is endothermic, and entropy increases. (3) It is exothermic, and entropy decreases. (4) It is exothermic, and entropy increases. P.S./Chem.–Jan. ’10 H [6] 50 The diagram below represents an operating electrochemical cell and the balanced ionic equation for the reaction occurring in the cell. Wire Wire V Voltmeter Salt bridge Zn(s) 2+ Ni(s) 2+ Zn (aq) Ni (aq) 2+ 2+ Zn(s) + Ni (aq) Zn (aq) + Ni(s) Which statement identifies the part of the cell that conducts electrons and describes the direction of electron flow as the cell operates? (1) Electrons flow through the salt bridge from the Ni(s) to the Zn(s). (2) Electrons flow through the salt bridge from the Zn(s) to the Ni(s). (3) Electrons flow through the wire from the Ni(s) to the Zn(s). (4) Electrons flow through the wire from the Zn(s) to the Ni(s). P.S./Chem.–Jan. ’10 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 Based on Table G, determine the total mass of NH3 that must be dissolved in 200. grams of water to produce a saturated solution at 20.°C. [1] 52 Determine the total time that must elapse until only ¼ of an original sample of the radioisotope Rn-222 remains unchanged. [1] Base your answers to questions 53 through 55 on the information below. A phase change for carbon dioxide that occurs spontaneously at 20.°C and 1.0 atmosphere is represented by the balanced equation below. CO2(s) + energy → CO2(g) 53 Write the name of this phase change. [1] 54 Describe what happens to the potential energy of the CO2 molecules as this phase change occurs. [1] 55 In your answer booklet, use the key to draw at least five molecules in the box to represent CO2 after this phase change is completed. [1] Base your answers to questions 56 and 57 on the information below. The dissolving of solid lithium bromide in water is represented by the balanced equation below. HO 2 LiBr(s) ⎯⎯⎯ → Li +(aq) + Br − (aq) 56 Calculate the total mass of LiBr(s) required to make 500.0 grams of an aqueous solution of LiBr that has a concentration of 388 parts per million. Your response must include both a correct numerical setup and the calculated result. [2] 57 Based on Table F, identify one ion that reacts with Br− ions in an aqueous solution to form an insoluble compound. [1] P.S./Chem.–Jan. ’10 [8] Base your answers to questions 58 through 60 on the information below. The formula below represents a hydrocarbon. H H C H H H H H C C C C H H H H H 58 Identify the homologous series to which this hydrocarbon belongs. [1] 59 Explain, in terms of carbon-carbon bonds, why this hydrocarbon is saturated. [1] 60 In the space in your answer booklet, draw a structural formula for one isomer of this hydrocarbon. [1] Base your answers to questions 61 through 63 on the information below. The atomic and ionic radii for sodium and chlorine are shown in the table below. Atomic and Ionic Radii Particle Radius (pm) Na atom 190. Na+ ion 102 Cl atom 97 Cl− ion 181 61 Write the ground state electron configuration for the ion that has a radius of 181 picometers. [1] 62 Convert the radius of an Na+ ion to meters. [1] 63 Explain, in terms of atomic structure, why the radius of an Na atom is larger than the radius of an Na+ ion. [1] P.S./Chem.–Jan. ’10 [9] [OVER] Base your answers to questions 64 and 65 on the information below. The nucleus of one boron atom has five protons and four neutrons. 64 Determine the total number of electrons in the boron atom. [1] 65 Determine the total charge of the boron nucleus. [1] P.S./Chem.–Jan. ’10 [10] Part C Answer all questions in this part. Directions (66–84): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 66 through 68 on the information below. At STP, iodine, I2, is a crystal, and fluorine, F2, is a gas. Iodine is soluble in ethanol, forming a tincture of iodine. A typical tincture of iodine is 2% iodine by mass. 66 Compare the strength of the intermolecular forces in a sample of I2 at STP to the strength of the intermolecular forces in a sample of F2 at STP. [1] 67 In the space in your answer booklet, draw a Lewis electron-dot diagram for a molecule of I2. [1] 68 Determine the total mass of I2 in 25 grams of this typical tincture of iodine. [1] Base your answers to questions 69 through 71 on the information below. In a laboratory investigation, magnesium reacts with hydrochloric acid to produce hydrogen gas and magnesium chloride. This reaction is represented by the unbalanced equation below. Mg(s) + HCl(aq) → H2(g) + MgCl2(aq) 69 State, in terms of the relative activity of elements, why this reaction is spontaneous. [1] 70 Balance the equation in your answer booklet, using the smallest whole-number coefficients. [1] 71 Write a balanced half-reaction equation for the oxidation that occurs. [1] P.S./Chem.–Jan. ’10 [11] [OVER] Base your answers to questions 72 through 75 on the information below. An experiment is performed to determine how concentration affects the rate of reaction. In each of four trials, equal volumes of solution A and solution B are mixed while temperature and pressure are held constant. The concentration of solution B is held constant, but the concentration of solution A is varied. The concentration of solution A and the time for the reaction to go to completion for each trial are recorded in the data table below. Data Table Trial Concentration of Solution A (M) Reaction Time (s) 1 0.0200 4.5 2 0.0150 7.0 3 0.0100 12.0 4 0.0050 20.0 72 Describe the relationship between the concentration of solution A and the time for the reaction to go to completion. [1] 73 On the grid in your answer booklet, mark an appropriate scale on the axis labeled “Reaction Time (s).” [1] 74 On the same grid, plot the data from the data table. Circle and connect the points. [1] 75 Identify one factor, other than the concentration of the solutions, that can affect the rate of this reaction. [1] P.S./Chem.–Jan. ’10 [12] Base your answers to questions 76 through 78 on the information below. Carbon has three naturally occurring isotopes, C-12, C-13, and C-14. Diamond and graphite are familiar forms of solid carbon. Diamond is one of the hardest substances known, while graphite is a very soft substance. Diamond has a rigid network of bonded atoms. Graphite has atoms bonded in thin layers that are held together by weak forces. Recent experiments have produced new forms of solid carbon called fullerenes. One fullerene, C60, is a spherical, cagelike molecule of carbon. 76 Determine both the total number of protons and the total number of neutrons in an atom of the naturally occurring carbon isotope with the largest mass number. [1] 77 Identify the type of bonding in a fullerene molecule. [1] 78 State, in terms of the arrangement of atoms, the difference in hardness between diamond and graphite. [1] Base your answers to questions 79 through 81 on the information below. Hydrocarbons and fissionable nuclei are among the sources used for the production of energy in the United States. A chemical reaction produces much less energy than a nuclear reaction per mole of reactant. The balanced chemical equation below represents the reaction of one molecule of a hydrocarbon with two molecules of oxygen. Chemical equation: CH4 + 2O2 → CO2 + 2H2O + 1.48 × 10−18 J The nuclear equation below represents one of the many possible reactions for one fissionable nucleus. In this equation, X represents a missing product. 89 1 −11 J Nuclear equation: 10n + 235 92U → 36Kr + X + 30n + 3.36 × 10 79 Identify the type of organic reaction represented by the chemical equation. [1] 80 On the labeled axes in your answer booklet, draw a potential energy diagram for the reaction of the hydrocarbon with oxygen. [1] 81 Write an isotopic notation for the missing product represented by X in the nuclear equation. [1] P.S./Chem.–Jan. ’10 [13] [OVER] Base your answers to questions 82 through 84 on the information below. The diagram below shows a system in which water is being decomposed into oxygen gas and hydrogen gas. Litmus is used as an indicator in the water. The litmus turns red in test tube 1 and blue in test tube 2. Battery O2 gas H2 gas Electrodes Water containing an electrolyte and litmus Test tube 1 Test tube 2 The oxidation and reduction occurring in the test tubes are represented by the balanced equations below. Test tube 1: 2H2O(ᐉ) → O2(g) + 4H+(aq) + 4e− Test tube 2: 4H2O(ᐉ) + 4e− → 2H2(g) + 4OH−(aq) 82 Identify the information in the diagram that indicates this system is an electrolytic cell. [1] 83 Determine the change in oxidation number of oxygen during the reaction in test tube 1. [1] 84 Explain, in terms of the products formed in test tube 2, why litmus turns blue in test tube 2. [1] P.S./Chem.–Jan. ’10 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING Tear Here CHEMISTRY Thursday, January 28, 2010 — 1:15 to 4:15 p.m., only ANSWER SHEET I Male I Female Grade . . . . . . . . . . . . Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sex: Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Record your answers to Part A and Part B–1 on this answer sheet. Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score Write your answers to Part B–2 and Part C in your answer booklet. Tear Here The declaration below must be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 28, 2010 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 16 C 19 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in Part B–2 and Part C. Record your answers in this booklet. Part B–2 Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . For Raters Only 51 g 51 52 d 52 53 __________________________________ 53 54 54 55 Key = CO2 molecule 55 For Raters Only 56 56 g 57 __________________________________ 57 58 __________________________________ 58 59 59 60 60 [2] For Raters Only 61 __________________________________ 61 62 __________________________________ m 62 63 63 64 64 65 65 Total Score for Part B–2 [3] [OVER] For Raters Only Part C 66 66 67 67 68 68 g 69 69 70 ________ Mg(s) + ________ HCl(aq) → ________ H2(g) + ________ MgCl2(aq) 70 71 71 [4] For Raters Only 72 72 73 and 74 Reaction Time (s) Reaction Time Versus Concentration of Solution A 73 74 0 0.0050 0.0100 0.0150 0.0200 Concentration of Solution A (M) 75 75 76 Protons: 76 Neutrons: 77 77 78 78 [5] [OVER] For Raters Only 79 __________________________________ 79 Potential Energy 80 80 Reaction Coordinate 81 81 82 82 83 From ________ to ________ 83 84 84 Total Score for Part C [6] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 16, 2010 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. The answers to all questions in this examination are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers in your answer booklet. When you have completed the examination, you must sign the statement printed on the first page of your answer booklet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write in your answer booklet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 6 Which Group 14 element is classified as a metal? (1) carbon (3) silicon (2) germanium (4) tin 1 The gold foil experiment led to the conclusion that each atom in the foil was composed mostly of empty space because most alpha particles directed at the foil (1) passed through the foil (2) remained trapped in the foil (3) were deflected by the nuclei in gold atoms (4) were deflected by the electrons in gold atoms 7 The light emitted from a flame is produced when electrons in an excited state (1) absorb energy as they move to lower energy states (2) absorb energy as they move to higher energy states (3) release energy as they move to lower energy states (4) release energy as they move to higher energy states 2 Which subatomic particles are located in the nucleus of a carbon atom? (1) protons, only (2) neutrons, only (3) protons and neutrons (4) protons and electrons 8 An atom of which element has the greatest attraction for electrons in a chemical bond? (1) As (3) Ge (2) Ga (4) Se 3 Which part of a helium atom is positively charged? (1) electron (3) nucleus (2) neutron (4) orbital 9 Which formula represents a polar molecule? (1) H2 (3) CO2 (2) H2O (4) CCl4 4 The mass of a proton is approximately equal to the mass of (1) an alpha particle (3) a neutron (2) an electron (4) a positron 10 Two categories of compounds are (1) covalent and molecular (2) covalent and metallic (3) ionic and molecular (4) ionic and metallic 5 At STP, solid carbon can exist as diamond and graphite. Compared to the molecular structure and chemical properties of diamond, graphite has (1) a different molecular structure and different properties (2) a different molecular structure and the same properties (3) the same molecular structure and different properties (4) the same molecular structure and the same properties P.S./Chem.–June ’10 11 Which type of bond is found between atoms of solid cobalt? (1) nonpolar covalent (3) metallic (2) polar covalent (4) ionic [2] 19 A chemical reaction between iron atoms and oxygen molecules can only occur if (1) the particles are heated (2) the atmospheric pressure decreases (3) there is a catalyst present (4) there are effective collisions between the particles 12 Which equation represents sublimation? (3) I2(ℓ) → I2(g) (1) I2(s) → I2(g) (2) I2(s) → I2(ℓ) (4) I2(ℓ) → I2(s) 13 Which sample of ethanol has particles with the highest average kinetic energy? (1) 10.0 mL of ethanol at 25°C (2) 10.0 mL of ethanol at 55°C (3) 100.0 mL of ethanol at 35°C (4) 100.0 mL of ethanol at 45°C 20 Given the equation representing a phase change at equilibrium: H2O(s) H2O(ℓ) 14 The molarity of an aqueous solution of NaCl is defined as the (1) grams of NaCl per liter of water (2) grams of NaCl per liter of solution (3) moles of NaCl per liter of water (4) moles of NaCl per liter of solution Which statement describes this equilibrium? (1) The H2O(s) melts faster than the H2O(ℓ) freezes. (2) The H2O(ℓ) freezes faster than the H2O(s) melts. (3) The mass of H2O(s) must equal the mass of H2O(ℓ). (4) The mass of H2O(ℓ) and the mass of H2O(s) each remain constant. 15 A real gas behaves least like an ideal gas under the conditions of (1) low temperature and low pressure (2) low temperature and high pressure (3) high temperature and low pressure (4) high temperature and high pressure 21 A molecule of an organic compound contains at least one atom of (1) carbon (3) nitrogen (2) chlorine (4) oxygen 16 Which sample of matter can be separated into different substances by physical means? (1) LiCl(aq) (3) NH3(g) (2) LiCl(s) (4) NH3(ℓ) 22 In a chemical reaction, the difference between the potential energy of the products and the potential energy of the reactants is equal to the (1) activation energy (2) entropy of the system (3) heat of fusion (4) heat of reaction 17 At STP, 1.0 liter of helium contains the same total number of atoms as (1) 1.0 L of Ne (3) 0.5 L of Rn (2) 2.0 L of Kr (4) 1.5 L of Ar 23 A carbon-carbon triple bond is found in a molecule of (1) butane (3) butene (2) butanone (4) butyne 18 Which statement describes the particles of an ideal gas? (1) The particles move in well-defined, circular paths. (2) When the particles collide, energy is lost. (3) There are forces of attraction between the particles. (4) The volume of the particles is negligible. P.S./Chem.–June ’10 [3] [OVER] 24 Which statement describes one characteristic of an operating electrolytic cell? (1) It produces electrical energy. (2) It requires an external energy source. (3) It uses radioactive nuclides. (4) It undergoes a spontaneous redox reaction. 28 During which process can 10.0 milliliters of a 0.05 M HCl(aq) solution be used to determine the unknown concentration of a given volume of NaOH(aq) solution? (1) evaporation (3) filtration (2) distillation (4) titration 25 Which compound when dissolved in water is an Arrhenius acid? (1) CH3OH (3) NaCl (2) HCl (4) NaOH 29 Which radioisotope is matched with its decay mode? (1) H-3 and γ (3) N-16 and α (2) K-42 and β+ (4) P-32 and β− 26 An acid can be defined as an (3) OH− acceptor (1) H+ acceptor (2) H+ donor (4) OH− donor 30 Which reaction is accompanied by the release of the greatest amount of energy? (1) combustion of 10. g of propane (2) electrolysis of 10. g of water (3) nuclear fission of 10. g of uranium (4) oxidation of 10. g of iron 27 Which nuclear emission has no charge and no mass? (1) alpha particle (3) gamma ray (2) beta particle (4) positron P.S./Chem.–June ’10 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write in your answer booklet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 The total number of protons, electrons, and neutrons in each of four different atoms are shown in the table below. Subatomic Particles in Four Different Atoms Atom Total Number of Protons Total Number of Electrons Total Number of Neutrons A 6 6 7 D 6 6 8 X 7 7 8 Z 8 8 9 Which two atoms are isotopes of the same element? (1) A and D (3) X and D (2) A and Z (4) X and Z 35 Which characteristics both generally decrease when the elements in Period 3 on the Periodic Table are considered in order from left to right? (1) nonmetallic properties and atomic radius (2) nonmetallic properties and ionization energy (3) metallic properties and atomic radius (4) metallic properties and ionization energy 32 Which Lewis electron-dot diagram represents an atom in the ground state for a Group 13 element? X X X X (1) (2) (3) (4) 33 Which element forms a compound with chlorine with the general formula MCl? (1) Rb (3) Re (2) Ra (4) Rn 36 Which formula is both a molecular and an empirical formula? (1) C6H12O6 (3) C3H8O (2) C2H4O2 (4) C4H8 34 A sample of an element has a mass of 34.261 grams and a volume of 3.8 cubic centimeters. To which number of significant figures should the calculated density of the sample be expressed? (1) 5 (3) 3 (2) 2 (4) 4 37 An atom of argon in the ground state tends not to bond with an atom of a different element because the argon atom has (1) more protons than neutrons (2) more neutrons than protons (3) a total of two valence electrons (4) a total of eight valence electrons P.S./Chem.–June ’10 [5] [OVER] 38 Which formula represents a molecule having a nonpolar covalent bond? H H C N H H H H C C H H (1) H H (3) H H H C H H C H 41 A sample of gas confined in a cylinder with a movable piston is kept at constant pressure. The volume of the gas doubles when the temperature of the gas is changed from (1) 400. K to 200. K (3) 400.°C to 200.°C (2) 200. K to 400. K (4) 200.°C to 400.°C H 42 According to Table F, which compound is soluble in water? (1) barium phosphate (3) silver iodide (2) calcium sulfate (4) sodium perchlorate OH H (4) (2) 43 Given the equation representing a system at equilibrium: N2(g) + 3H2(g) 2NH3(g) + energy 39 Which compound has the lowest vapor pressure at 50°C? (1) ethanoic acid (3) propanone (2) ethanol (4) water Which changes occur when the temperature of this system is decreased? (1) The concentration of H2(g) increases and the concentration of N2(g) increases. (2) The concentration of H2(g) decreases and the concentration of N2(g) increases. (3) The concentration of H2(g) decreases and the concentration of NH3(g) decreases. (4) The concentration of H2(g) decreases and the concentration of NH3(g) increases. Potential Energy 40 Given the potential energy diagram and equation representing the reaction between substances A and D: G 44 Which formula represents an unsaturated hydrocarbon? A+D H H O C C H H C C (1) Reaction Coordinate C H H (3) G According to Table I, substance G could be (1) HI(g) (3) CO2(g) (2) H2O(g) (4) C2H6(g) H H H H C C C H H H (2) P.S./Chem.–June ’10 H H H A+D H [6] H H H C O H (4) H H C C H H H 48 Which laboratory test result can be used to determine if KCl(s) is an electrolyte? (1) pH of KCl(aq) (2) pH of KCl(s) (3) electrical conductivity of KCl(aq) (4) electrical conductivity of KCl(s) 45 Which half-reaction equation represents the reduction of an iron(II) ion? (3) Fe3+ + e− → Fe2+ (1) Fe2+ → Fe3+ + e− (2) Fe2+ + 2e− → Fe (4) Fe → Fe2+ + 2e− 46 Which metal is more active than H2? (1) Ag (3) Cu (2) Au (4) Pb 49 Which compound is produced when HCl(aq) is neutralized by Ca(OH)2(aq)? (3) HClO (1) CaCl2 (2) CaH2 (4) HClO2 47 Given the balanced ionic equation representing the reaction in an operating voltaic cell: Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s) 50 Which nuclides are used to date the remains of a once-living organism? (1) C-14 and C-12 (3) I-131 and Xe-131 (2) Co-60 and Co-59 (4) U-238 and Pb-206 The flow of electrons through the external circuit in this cell is from the (1) Cu anode to the Zn cathode (2) Cu cathode to the Zn anode (3) Zn anode to the Cu cathode (4) Zn cathode to the Cu anode P.S./Chem.–June ’10 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–64): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 What is the total number of electron pairs shared between the carbon atom and one of the oxygen atoms in a carbon dioxide molecule? [1] 52 Explain, in terms of subatomic particles, why the radius of a chloride ion is larger than the radius of a chlorine atom. [1] 53 Explain, in terms of valence electrons, why the bonding in magnesium oxide, MgO, is similar to the bonding in barium chloride, BaCl2. [1] Base your answers to questions 54 and 55 on the information below. An atom in an excited state has an electron configuration of 2-7-2. 54 Explain, in terms of subatomic particles, why this excited atom is electrically neutral. [1] 55 Write the electron configuration of this atom in the ground state. [1] Base your answers to questions 56 through 58 on the information below. Glycine, NH2CH2COOH, is an organic compound found in proteins. Acetamide, CH3CONH2, is an organic compound that is an excellent solvent. Both glycine and acetamide consist of the same four elements, but the compounds have different functional groups. 56 In the space in your answer booklet, calculate the gram-formula mass of glycine. Your response must include both a numerical setup and the calculated result. [2] 57 Identify one functional group in a glycine molecule. [1] 58 In the space in your answer booklet, draw a structural formula for acetamide. [1] P.S./Chem.–June ’10 [8] Base your answers to questions 59 through 61 on the information below. Heat is added to a 200.-gram sample of H2O(s) to melt the sample at 0°C. Then the resulting H2O(ℓ) is heated to a final temperature of 65°C. 59 Determine the total amount of heat required to completely melt the sample. [1] 60 In the space in your answer booklet, show a numerical setup for calculating the total amount of heat required to raise the temperature of the H2O(ℓ) from 0°C to its final temperature. [1] 61 Compare the amount of heat required to vaporize a 200.-gram sample of H2O(ℓ) at its boiling point to the amount of heat required to melt a 200.-gram sample of H2O(s) at its melting point. [1] Base your answers to questions 62 through 64 on the information below. When a uranium-235 nucleus absorbs a slow-moving neutron, different nuclear reactions may occur. One of these possible reactions is represented by the complete, balanced equation below. Equation 1: 235U 92 142 1 + 10n → 92 36Kr + 56Ba + 20n + energy For this reaction, the sum of the masses of the products is slightly less than the sum of the masses of the reactants. Another possible reaction of U-235 is represented by the incomplete, balanced equation below. Equation 2: 235U 92 1 + 10n → 92 38Sr + _____ + 20n + energy 62 Identify the type of nuclear reaction represented by equation 1. [1] 63 Write a notation for the missing product in equation 2. [1] 64 Determine the half-life of krypton-92 if only 6.0 milligrams of an original 96.0-milligram sample remains unchanged after 7.36 seconds. [1] P.S./Chem.–June ’10 [9] [OVER] Part C Answer all questions in this part. Directions (65–83): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 65 through 68 on the information below. In a laboratory, a student makes a solution by completely dissolving 80.0 grams of KNO3(s) in 100.0 grams of hot water. The resulting solution has a temperature of 60.°C. The room temperature in the laboratory is 22°C. 65 Classify, in terms of saturation, the type of solution made by the student. [1] 66 Compare the boiling point of the solution at standard pressure to the boiling point of water at standard pressure. [1] 67 Describe the direction of heat flow between the solution made by the student and the air in the laboratory. [1] 68 Describe a laboratory procedure that can be used to recover the solid solute from the aqueous solution. [1] P.S./Chem.–June ’10 [10] Base your answers to questions 69 through 71 on the information below. At room temperature, a reaction occurs when KIO3(aq) is mixed with NaHSO3(aq) that contains a small amount of starch. The colorless reaction mixture turns dark blue after a period of time that depends on the concentration of the reactants. In a laboratory, 12 drops of a 0.02 M NaHSO3(aq) solution containing starch were placed in each of six test tubes. A different number of drops of 0.02 M KIO3(aq) and enough water to maintain a constant volume were added to each test tube and the time for the dark-blue color to appear was measured. The data were recorded in the table below. Data Table Test Tube A B C D E F Number of Drops of 0.02 M KIO3(aq) 2 4 6 8 10 12 210. 88 49 39 33 27 Time for Dark-Blue Color to Appear (s) 69 On the grid in your answer booklet: • Mark an appropriate scale on the axis labeled “Time (s).” [1] • Plot the data from the data table. Circle and connect the points. [1] 70 State how increasing the number of drops of 0.02 M KIO3(aq) used in the reaction affects the rate of reaction. [1] 71 Identify one factor, other than the concentration of the reactants, that would affect the rate of this reaction. [1] Base your answers to questions 72 through 75 on the information below. The Solvay process is a multistep industrial process used to produce washing soda, Na2CO3(s). In the last step of the Solvay process, NaHCO3(s) is heated to 300°C, producing washing soda, water, and carbon dioxide. This reaction is represented by the balanced equation below. 2NaHCO3(s) + heat → Na2CO3(s) + H2O(g) + CO2(g) 72 Write the IUPAC name for washing soda. [1] 73 Identify the type of chemical reaction represented by the equation. [1] 74 State evidence that indicates the entropy of the products is greater than the entropy of the reactant. [1] 75 Determine the total mass of washing soda produced if 3360. kilograms of NaHCO3 reacts completely to produce 360. kilograms of H2O and 880. kilograms of CO2. [1] P.S./Chem.–June ’10 [11] [OVER] Base your answers to questions 76 through 79 on the information below. In liquid water, an equilibrium exists between H2O(ℓ) molecules, H+(aq) ions, and OH−(aq) ions. A person experiencing acid indigestion after drinking tomato juice can ingest milk of magnesia to reduce the acidity of the stomach contents. Tomato juice has a pH value of 4. Milk of magnesia, a mixture of magnesium hydroxide and water, has a pH value of 10. 76 Complete the equation in your answer booklet for the equilibrium that exists in liquid water. [1] 77 Compare the hydrogen ion concentration in tomato juice to the hydrogen ion concentration in milk of magnesia. [1] 78 Identify the negative ion found in milk of magnesia. [1] 79 What is the color of thymol blue indicator when placed in a sample of milk of magnesia? [1] Base your answers to questions 80 through 83 on the information below. Two sources of copper are cuprite, which has the IUPAC name copper(I) oxide, and malachite, which has the formula Cu2CO3(OH)2. Copper is used in home wiring and electric motors because it has good electrical conductivity. Other uses of copper not related to its electrical conductivity include coins, plumbing, roofing, and cooking pans. Aluminum is also used for cooking pans. At room temperature, the electrical conductivity of a copper wire is 1.6 times greater than an aluminum wire with the same length and cross-sectional area. At room temperature, the heat conductivity of copper is 1.8 times greater than the heat conductivity of aluminum. At STP, the density of copper is 3.3 times greater than the density of aluminum. 80 Write the chemical formula of cuprite. [1] 81 Determine the oxidation number of oxygen in the carbonate ion found in malachite. [1] 82 Identify one physical property of copper that makes it a good choice for uses that are not related to electrical conductivity. [1] 83 Identify one physical property of aluminum that could make it a better choice than copper for a cooking pan. [1] P.S./Chem.–June ’10 [12] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, June 16, 2010 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in this examination. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score The declaration below must be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature For Raters Only Part B–2 51 51 52 52 53 53 54 54 55 55 [2] For Raters Only 56 56 g/mol 57 57 58 58 59 J 59 60 60 61 61 [3] [OVER] For Raters Only 62 62 63 63 64 s 64 Total Score for Part B–2 [4] For Raters Only Part C 65 65 66 66 67 67 68 68 [5] [OVER] For Raters Only 69 Time (s) Reaction Time 69 0 2 4 6 8 10 12 Number of Drops 70 70 71 71 [6] For Raters Only 72 72 73 73 74 74 75 kg 75 76 ________________ (ℓ) ________________ (aq) + ________________ (aq) 76 77 77 78 78 79 79 80 80 81 81 82 82 83 83 Total Score for Part C [7] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, August 18, 2010 — 12:30 to 3:30 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. The answers to all questions in this examination are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers in your answer booklet. When you have completed the examination, you must sign the statement printed on the first page of your answer booklet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write in your answer booklet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 7 A balanced equation representing a chemical reaction can be written using (1) chemical formulas and mass numbers (2) chemical formulas and coefficients (3) first ionization energies and mass numbers (4) first ionization energies and coefficients 1 What is the total number of valence electrons in a calcium atom in the ground state? (1) 8 (3) 18 (2) 2 (4) 20 2 Which subatomic particles are located in the nucleus of an He-4 atom? (1) electrons and neutrons (2) electrons and protons (3) neutrons and protons (4) neutrons, protons, and electrons 8 Every water molecule has two hydrogen atoms bonded to one oxygen atom. This fact supports the concept that elements in a compound are (1) chemically combined in a fixed proportion (2) chemically combined in proportions that vary (3) physically mixed in a fixed proportion (4) physically mixed in proportions that vary 3 In the late 1800s, experiments using cathode ray tubes led to the discovery of the (1) electron (3) positron (2) neutron (4) proton 9 The percent composition by mass of nitrogen in NH4OH (gram-formula mass = 35 grams/mole) is equal to 4 The atomic mass of titanium is 47.88 atomic mass units. This atomic mass represents the (1) total mass of all the protons and neutrons in an atom of Ti (2) total mass of all the protons, neutrons, and electrons in an atom of Ti (3) weighted average mass of the most abundant isotope of Ti (4) weighted average mass of all the naturally occurring isotopes of Ti 4 35 × 100 (3) 35 14 × 100 (2) 14 35 × 100 (4) 35 4 × 100 10 Which Group 15 element exists as diatomic molecules at STP? (1) phosphorus (3) bismuth (2) nitrogen (4) arsenic 5 An atom of which element has the largest atomic radius? (1) Fe (3) Si (2) Mg (4) Zn 11 What is the total number of electrons shared in a double covalent bond? (1) 1 (3) 3 (2) 2 (4) 4 6 Which element requires the least amount of energy to remove the most loosely held electron from a gaseous atom in the ground state? (1) bromine (3) sodium (2) calcium (4) silver P.S./Chem.–Aug. ’10 (1) [2] 18 Which gas sample at STP has the same total number of molecules as 2.0 liters of CO2(g) at STP? (3) 3.0 L of H2S(g) (1) 5.0 L of CO2(g) 12 Given the balanced equation representing a reaction: Br2 + energy → Br + Br Which statement describes the energy change and bonds in this reaction? (1) Energy is released as bonds are broken. (2) Energy is released as bonds are formed. (3) Energy is absorbed as bonds are broken. (4) Energy is absorbed as bonds are formed. (2) 2.0 L of Cl2(g) 19 Petroleum can be separated by distillation because the hydrocarbons in petroleum are (1) elements with identical boiling points (2) elements with different boiling points (3) compounds with identical boiling points (4) compounds with different boiling points 13 Which substance can not be broken down by a chemical change? (1) methane (3) tungsten (2) propanal (4) water 20 Which compound is insoluble in water? (1) KOH (3) Na 3 PO4 (2) NH4Cl 14 Object A at 40.°C and object B at 80.°C are placed in contact with each other. Which statement describes the heat flow between the objects? (1) Heat flows from object A to object B. (2) Heat flows from object B to object A. (3) Heat flows in both directions between the objects. (4) No heat flow occurs between the objects. (4) PbSO4 21 A gas sample is at 25°C and 1.0 atmosphere. Which changes in temperature and pressure will cause this sample to behave more like an ideal gas? (1) decreased temperature and increased pressure (2) decreased temperature and decreased pressure (3) increased temperature and increased pressure (4) increased temperature and decreased pressure 15 Which unit can be used to express the concentration of a solution? (1) L/s (3) ppm (2) J/g (4) kPa 22 The isotopes K-37 and K-42 have the same (1) decay mode (2) bright-line spectrum (3) mass number for their atoms (4) total number of neutrons in their atoms 16 Which formula represents a mixture? (1) C6H12O6(ℓ) (3) LiCl(aq) (2) C6H12O6(s) (4) 6.0 L of He(g) (4) LiCl(s) 17 Which sample has particles with the lowest average kinetic energy? (1) 1.0 g of I2 at 50.°C 23 Which element is present in all organic compounds? (1) carbon (3) nitrogen (2) hydrogen (4) oxygen (2) 2.0 g of I2 at 30.°C (3) 7.0 g of I2 at 40.°C (4) 9.0 g of I2 at 20.°C P.S./Chem.–Aug. ’10 [3] [OVER] 24 Each of four test tubes contains a different concentration of HCl(aq) at 25°C. A 1-gram cube of Zn is added to each test tube. In which test tube is the reaction occurring at the fastest rate? 1M HCl(aq) 10 mL (1) 0.1 M HCl(aq) 10 mL (2) 0.01 M HCl(aq) 0.001 M HCl(aq) 10 mL (3) 27 Based on the results of testing colorless solutions with indicators, which solution is most acidic? (1) a solution in which bromthymol blue is blue (2) a solution in which bromcresol green is blue (3) a solution in which phenolphthalein is pink (4) a solution in which methyl orange is red 28 According to one acid-base theory, water acts as an acid when an H2O molecule (3) accepts an H− (1) accepts an H+ + (2) donates an H (4) donates an H− 10 mL (4) 29 In which type of reaction is an atom of one element converted to an atom of a different element? (1) decomposition (3) saponification (2) neutralization (4) transmutation 25 Which energy conversion occurs during the operation of an electrolytic cell? (1) chemical energy to electrical energy (2) electrical energy to chemical energy (3) nuclear energy to electrical energy (4) electrical energy to nuclear energy 30 Which nuclide is listed with its half-life and decay mode? (1) K-37, 1.24 h, α (2) N-16, 7.2 s, β− (3) Rn-222, 1.6 × 103 y, α (4) U-235, 7.1 × 108 y, β− 26 Which compound is an Arrhenius acid? (1) CaO (3) K2O (2) HCl P.S./Chem.–Aug. ’10 (4) NH3 [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write in your answer booklet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 The table below shows the number of subatomic particles in atom X and in atom Z. Subatomic Particles in Two Atoms Atom Number of Protons Number of Neutrons Number of Electrons X 6 6 6 Z 6 7 6 Atom X and atom Z are isotopes of the element (1) aluminum (3) magnesium (2) carbon (4) nitrogen 36 Given the balanced equation representing a reaction: 32 The greatest composition by mass in an atom of 178 O is due to the total mass of its (1) electrons (3) positrons (2) neutrons (4) protons 2NaCl(ℓ) → 2Na(ℓ) + Cl2(g) A 1170.-gram sample of NaCl(ℓ) completely reacts, producing 460. grams of Na(ℓ). What is the total mass of Cl2(g) produced? (1) 355 g (3) 1420. g (2) 710. g (4) 1630. g 33 The bond between which two atoms is most polar? (1) Br and Cl (3) I and Cl (2) Br and F (4) I and F 37 Given the formula representing a hydrocarbon: 34 In the formula X2(SO4)3, the X represents a metal. This metal could be located on the Periodic Table in (1) Group 1 (3) Group 13 (2) Group 2 (4) Group 14 H H C C H C H C C H H H H 35 At STP, which element is solid, brittle, and a poor conductor of electricity? (1) Al (3) Ne (2) K (4) S The molecular formula and the empirical formula for this hydrocarbon are (3) C4H8 and CH2 (1) C5H10 and CH2 (2) C5H10 and CH3 P.S./Chem.–Aug. ’10 H H [5] (4) C4H8 and CH3 [OVER] 38 Which element forms an ionic compound when it reacts with lithium? (1) K (3) Kr (2) Fe (4) Br 44 The entropy of a sample of CO2 increases as the CO2 changes from (1) gas to liquid (3) liquid to solid (2) gas to solid (4) solid to gas 39 Given the formula representing a molecule: 45 Which two factors must be equal when a chemical reaction reaches equilibrium? (1) the concentration of the reactants and the concentration of the products (2) the number of reactant particles and the number of product particles (3) the rate of the forward reaction and the rate of the reverse reaction (4) the mass of the reactants and the mass of the products H C C H The molecule is (1) symmetrical and polar (2) symmetrical and nonpolar (3) asymmetrical and polar (4) asymmetrical and nonpolar 40 Which compound has both ionic and covalent bonds? (1) CO2 (3) NaI (2) CH3OH (4) Na2CO3 46 Which formula represents an unsaturated hydrocarbon? (1) C5H12 (3) C7H16 (2) C6H14 (4) C8H14 41 A cylinder with a movable piston contains a sample of gas having a volume of 6.0 liters at 293 K and 1.0 atmosphere. What is the volume of the sample after the gas is heated to 303 K, while the pressure is held at 1.0 atmosphere? (1) 9.0 L (3) 5.8 L (2) 6.2 L (4) 4.0 L 47 The reaction between an organic acid and an alcohol produces (1) an aldehyde (3) an ether (2) a ketone (4) an ester 48 Which balanced equation represents a redox reaction? (1) AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) (2) H2CO3(aq) → H2O(ℓ) + CO2(g) (3) NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(ℓ) (4) Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) 42 What is the minimum amount of heat required to completely melt 20.0 grams of ice at its melting point? (1) 20.0 J (3) 6680 J (2) 83.6 J (4) 45 200 J 49 A solution with a pH of 2.0 has a hydronium ion concentration ten times greater than a solution with a pH of (1) 1.0 (3) 3.0 (2) 0.20 (4) 20. 43 As the temperature of a chemical reaction in the gas phase is increased, the rate of the reaction increases because (1) fewer particle collisions occur (2) more effective particle collisions occur (3) the required activation energy increases (4) the concentration of the reactants increases P.S./Chem.–Aug. ’10 50 Which isotope is used to treat cancer? (1) C-14 (3) Co-60 (2) U-238 (4) Pb-206 [6] Part B–2 Answer all questions in this part. Directions (51–63): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 In your answer booklet, write an electron configuration for a silicon atom in an excited state. [1] Base your answers to questions 52 and 53 on the information below. Densities of Group 14 Elements Element Density at STP (g/cm3) C 3.51 Si 2.33 Ge 5.32 Sn 7.31 Pb 11.35 52 Identify one element from this table for each type of element: metal, metalloid, and nonmetal. [1] 53 Calculate the volume of a tin block that has a mass of 95.04 grams at STP. Your response must include both a numerical setup and the calculated result. [2] Base your answers to questions 54 through 56 on the elements in Group 2 on the Periodic Table. 54 State the general trend in first ionization energy for the elements in Group 2 as these elements are considered in order from top to bottom in the group. [1] 55 State, in terms of the number of electron shells, why the radius of a strontium atom in the ground state is larger than the radius of a magnesium atom in the ground state. [1] 56 Explain, in terms of atomic structure, why the elements in Group 2 have similar chemical properties. [1] P.S./Chem.–Aug. ’10 [7] [OVER] Base your answers to questions 57 and 58 on the information below. Heat is added to a sample of liquid water, starting at 80.°C, until the entire sample is a gas at 120.°C. This process, occurring at standard pressure, is represented by the balanced equation below. H2O(ℓ) + heat → H2O(g) 57 In the box in your answer booklet, using the key, draw a particle diagram to represent at least five molecules of the product of this physical change at 120.°C. [2] 58 On the diagram in your answer booklet, complete the heating curve for this physical change. [1] Base your answers to questions 59 and 60 on the information below. In the gold foil experiment, a thin sheet of gold was bombarded with alpha particles. Almost all the alpha particles passed straight through the foil. Only a few alpha particles were deflected from their original paths. 59 State one conclusion about atomic structure based on the observation that almost all alpha particles passed straight through the foil. [1] 60 Explain, in terms of charged particles, why some of the alpha particles were deflected. [1] Base your answers to questions 61 through 63 on the information below. Some Properties of Three Compounds at Standard Pressure Boiling Point (°C) Solubility in 100. Grams of H2O at 20.°C (g) ammonia –33.2 56 methane –161.5 Compound hydrogen chloride 0.002 –84.9 72 61 Convert the boiling point of hydrogen chloride at standard pressure to kelvins. [1] 62 Explain, in terms of molecular polarity, why hydrogen chloride is more soluble than methane in water at 20.°C and standard pressure. [1] 63 Explain, in terms of intermolecular forces, why ammonia has a higher boiling point than the other compounds in the table. [1] P.S./Chem.–Aug. ’10 [8] Part C Answer all questions in this part. Directions (64–81): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 64 through 66 on the information below. The diagram below represents an operating voltaic cell at 298 K and 1.0 atmosphere in a laboratory investigation. The reaction occurring in the cell is represented by the balanced ionic equation below. V Voltmeter Wire Salt bridge Ag(s) + Ni(s) 2+ Ag (aq) Ni (aq) + 2+ 2Ag (aq) + Ni(s) 2Ag(s) + Ni (aq) 64 Identify the anode in this cell. [1] 65 Determine the total number of moles of Ni2+(aq) ions produced when 4.0 moles of Ag+(aq) ions completely react in this cell. [1] 66 Write a balanced half-reaction equation for the reduction that occurs in this cell. [1] P.S./Chem.–Aug. ’10 [9] [OVER] Base your answers to questions 67 through 69 on the information below. Gasoline is a mixture composed primarily of hydrocarbons such as isooctane, which is also known as 2,2,4-trimethylpentane. Gasoline is assigned a number called an octane rating. Gasoline with an octane rating of 87 performs the same as a mixture that consists of 87% isooctane and 13% heptane. An alternative fuel, E-85, can be used in some automobiles. This fuel is a mixture of 85% ethanol and 15% gasoline. 67 State the octane rating of a gasoline sample that performs the same as a mixture consisting of 92% isooctane and 8% heptane. [1] 68 In the space in your answer booklet, draw a structural formula for a molecule of 2,2,4-trimethylpentane. [1] 69 Identify the functional group in a molecule of ethanol in the alternative fuel E-85. [1] Base your answers to questions 70 through 72 on the information below. Hydrogen peroxide, H2O2, is a water-soluble compound. The concentration of an aqueous hydrogen peroxide solution that is 3% by mass H2O2 is used as an antiseptic. When the solution is poured on a small cut in the skin, H2O2 reacts according to the balanced equation below. 2H2O2 → 2H2O + O2 70 Identify the type of chemical reaction represented by the balanced equation. [1] 71 Calculate the total mass of H2O2 in 20.0 grams of an aqueous H2O2 solution that is used as an antiseptic. Your response must include both a numerical setup and the calculated result. [2] 72 Determine the gram-formula mass of H2O2. [1] P.S./Chem.–Aug. ’10 [10] Base your answers to questions 73 and 74 on the information below. The catalytic converter in an automobile changes harmful gases produced during fuel combustion to less harmful exhaust gases. In the catalytic converter, nitrogen dioxide reacts with carbon monoxide to produce nitrogen and carbon dioxide. In addition, some carbon monoxide reacts with oxygen, producing carbon dioxide in the converter. These reactions are represented by the balanced equations below. Reaction 1: 2NO2(g) + 4CO(g) → N2(g) + 4CO2(g) + 1198.4 kJ Reaction 2: 2CO(g) + O2(g) → 2CO2(g) + 566.0 kJ 73 The potential energy diagram in your answer booklet represents reaction 1 without a catalyst. On the same diagram, draw a dashed line to indicate how potential energy changes when the reaction is catalyzed in the converter. [1] 74 Determine the oxidation number of carbon in each carbon compound in reaction 2. Your response must include both the sign and value of each oxidation number. [1] P.S./Chem.–Aug. ’10 [11] [OVER] Base your answers to questions 75 through 78 on the information below. In one trial of an investigation, 50.0 milliliters of HCl(aq) of an unknown concentration is titrated with 0.10 M NaOH(aq). During the titration, the total volume of NaOH(aq) added and the corresponding pH value of the reaction mixture are measured and recorded in the table below. Titration Data Total Volume of NaOH(aq) Added (mL) pH Value of Reaction Mixture 10.0 1.6 20.0 2.2 24.0 2.9 24.9 3.9 25.1 10.1 26.0 11.1 30.0 11.8 75 On the grid in your answer booklet, plot the data from the table. Circle and connect the points. [1] 76 Determine the total volume of NaOH(aq) added when the reaction mixture has a pH value of 7.0. [1] 77 Write a balanced equation that represents this neutralization reaction. [1] 78 In another trial, 40.0 milliliters of HCl(aq) is completely neutralized by 20.0 milliliters of this 0.10 M NaOH(aq). Calculate the molarity of the titrated acid in this trial. Your response must include both a numerical setup and the calculated result. [2] P.S./Chem.–Aug. ’10 [12] Base your answers to questions 79 through 81 on the information below. The radioisotope uranium-238 occurs naturally in Earth’s crust. The disintegration of this radioisotope is the first in a series of spontaneous decays. The sixth decay in this series produces the radioisotope radon-222. The decay of radon-222 produces the radioisotope polonium-218 that has a half life of 3.04 minutes. Eventually, the stable isotope lead-206 is produced by the alpha decay of an unstable nuclide. 79 Explain, in terms of electron configuration, why atoms of the radioisotope produced by the sixth decay in the U-238 disintegration series do not readily react to form compounds. [1] 80 Complete the nuclear equation in your answer booklet for the decay of the unstable nuclide that produces Pb-206, by writing a notation for the missing nuclide. [1] 81 Determine the original mass of a sample of Po-218, if 0.50 milligram of the sample remains unchanged after 12.16 minutes. [1] P.S./Chem.–Aug. ’10 [13] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Wednesday, August 18, 2010 — 12:30 to 3:30 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 15 C 20 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in this examination. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score The declaration below must be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature For Raters Only Part B–2 51 51 52 Metal: ________________________________ Metalloid: _____________________________ 52 Nonmetal: _____________________________ 53 53 cm3 54 54 55 55 56 56 [2] For Raters Only 57 Key = atom of hydrogen = atom of oxygen 57 Temperature 58 58 Heat Added 59 59 60 60 [3] [OVER] For Raters Only 61 K 61 62 62 63 63 Total Score for Part B–2 [4] For Raters Only Part C 64 65 64 mol 65 66 66 67 67 68 68 69 69 70 70 71 71 g 72 g/mol 72 [5] [OVER] For Raters Only Potential Energy 73 73 Reaction Coordinate 74 CO: _______________________________ 74 CO2: ______________________________ pH Value of Reaction Mixture 75 pH Value of Reaction Mixture Versus Total Volume of NaOH(aq) Added 14 13 12 11 10. 9 8 7 6 5 4 3 2 1 0 10.0 20.0 75 30.0 Total Volume of NaOH(aq) Added (mL) 76 mL 76 [6] For Raters Only 77 77 78 78 M 79 79 80 81 → 4 2 He + 206 82 Pb 80 mg 81 Total Score for Part C [7] PS/CHEMISTRY The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 27, 2011 — 1:15 to 4:15 p.m., only This is a test of your knowledge of chemistry. Use that knowledge to answer all questions in this examination. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. The answers to all questions in this examination are to be written in your separate answer booklet. Be sure to fill in the heading on the front of your answer booklet. All work should be written in pen, except for graphs and drawings, which should be done in pencil. You may use scrap paper to work out the answers to the questions, but be sure to record all your answers in your answer booklet. When you have completed the examination, you must sign the statement printed on the first page of your answer booklet, indicating that you had no unlawful knowledge of the questions or answers prior to the examination and that you have neither given nor received assistance in answering any of the questions during the examination. Your answer booklet cannot be accepted if you fail to sign this declaration. Notice. . . A four-function or scientific calculator and a copy of the Reference Tables for Physical Setting/Chemistry must be available for you to use while taking this examination. The use of any communications device is strictly prohibited when taking this examination. If you use any communications device, no matter how briefly, your examination will be invalidated and no score will be calculated for you. DO NOT OPEN THIS EXAMINATION BOOKLET UNTIL THE SIGNAL IS GIVEN. PS/CHEMISTRY Part A Answer all questions in this part. Directions (1–30): For each statement or question, write in your answer booklet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 1 An orbital is a region of space where there is a high probability of finding (1) a proton (3) a neutron (2) a positron (4) an electron 6 The valence electrons of a germanium atom in the ground state are located in the (1) first shell (3) third shell (2) second shell (4) fourth shell 2 Which statement matches a subatomic particle with its charge? (1) A neutron has a negative charge. (2) A proton has a negative charge. (3) A neutron has no charge. (4) A proton has no charge. 7 The elements on the Periodic Table are arranged in order of increasing (1) atomic mass (2) atomic number (3) first ionization energy (4) selected oxidation state 3 An atom of any element must contain (1) an equal number of protons and neutrons (2) an equal number of protons and electrons (3) more electrons than neutrons (4) more electrons than protons 8 Which list of elements contains a metal, a metalloid, a nonmetal, and a noble gas? (1) Be, Si, Cl, Kr (3) K, Fe, B, F (2) C, N, Ne, Ar (4) Na, Zn, As, Sb 9 The two forms of oxygen, O2(g) and O3(g), have (1) different molecular structures and identical properties (2) different molecular structures and different properties (3) identical molecular structures and identical properties (4) identical molecular structures and different properties 4 Which statement compares the masses of two subatomic particles? (1) The mass of an electron is greater than the mass of a proton. (2) The mass of an electron is greater than the mass of a neutron. (3) The mass of a proton is greater than the mass of an electron. (4) The mass of a proton is greater than the mass of a neutron. 10 The sum of the atomic masses of the atoms in one molecule of C3H6Br2 is called the (1) formula mass (2) isotopic mass (3) percent abundance (4) percent composition 5 The bright-line spectrum of sodium is produced when energy is (1) absorbed as electrons move from higher to lower electron shells (2) absorbed as electrons move from lower to higher electron shells (3) released as electrons move from higher to lower electron shells (4) released as electrons move from lower to higher electron shells PS/Chem.–Jan. ’11 11 What is the total number of electron pairs shared between the two atoms in an O2 molecule? (1) 1 (3) 6 (2) 2 (4) 4 [2] 12 When an atom of lithium loses an electron, atom becomes a (1) negative ion with a radius smaller than radius of the atom (2) negative ion with a radius larger than radius of the atom (3) positive ion with a radius smaller than radius of the atom (4) positive ion with a radius larger than radius of the atom 18 Which sample of water contains particles having the highest average kinetic energy? (1) 25 mL of water at 95°C (2) 45 mL of water at 75°C (3) 75 mL of water at 75°C (4) 95 mL of water at 25°C the the the the 19 Under which conditions of temperature and pressure does carbon dioxide gas behave most like an ideal gas? (1) low temperature and low pressure (2) low temperature and high pressure (3) high temperature and low pressure (4) high temperature and high pressure the 13 Given the balanced equation representing a reaction: 2NaCl → 2Na + Cl2 To break the bonds in NaCl, the reactant must (1) absorb energy (3) destroy energy (2) create energy (4) release energy 20 Which process results in a chemical change? (1) tearing tin foil (2) melting an iron bar (3) crushing an aluminum can (4) burning magnesium ribbon 14 A molecular compound is formed when a chemical reaction occurs between atoms of (1) chlorine and sodium (2) chlorine and yttrium (3) oxygen and hydrogen (4) oxygen and magnesium 21 For a chemical reaction, the heat of reaction is equal to the (1) potential energy of the reactants, only (2) potential energy of the products, only (3) potential energy of the products plus the potential energy of the reactants (4) potential energy of the products minus the potential energy of the reactants 15 Which substance can not be broken down by chemical means? (1) ammonia (3) methane (2) antimony (4) water 22 Given the equation representing a system at equilibrium: 16 Which two physical properties allow a mixture to be separated by chromatography? (1) hardness and boiling point (2) density and specific heat capacity (3) malleability and thermal conductivity (4) solubility and molecular polarity 2SO2(g) + O2(g) 2SO3(g) At equilibrium, the concentration of (1) SO2(g) must equal the concentration of SO3(g) (2) SO2(g) must be constant (3) O2(g) must equal the concentration of SO2(g) (4) O2(g) must be decreasing 17 The solubility of KCl(s) in water depends on the (1) pressure on the solution (2) rate of stirring (3) size of the KCl sample (4) temperature of the water PS/Chem.–Jan. ’11 [3] [OVER] 28 What is one benefit associated with a nuclear fission reaction? (1) The products are not radioactive. (2) Stable isotopes are used as reactants. (3) There is no chance of biological exposure. (4) A large amount of energy is produced. 23 The two isomers of butane have different (1) formula masses (3) molecular formulas (2) empirical formulas (4) structural formulas 24 An oxidation-reduction reaction involves the (1) sharing of electrons (2) sharing of protons (3) transfer of electrons (4) transfer of protons 29 Which balanced equation represents a fusion reaction? (1) 25 Which energy change occurs in an operating voltaic cell? (1) chemical to electrical (2) electrical to chemical (3) chemical to nuclear (4) nuclear to chemical + 01 n → 93 36 Kr + 140 56 Ba + 3 01 n (2) 21H + 31H → 42 He + 01 n (3) 14 7N + 42 He → (4) 226 88 Ra → 17 8O 222 86 Rn + 11H + 42 He 30 Which radioisotope emits alpha particles? (1) Fe-53 (3) Au-198 (2) Sr-90 (4) Pu-239 26 Which compound is an electrolyte? (1) butene (3) dimethyl ether (2) propane (4) methanoic acid 27 According to the Arrhenius theory, a base reacts with an acid to produce (1) ammonia and methane (2) ammonia and a salt (3) water and methane (4) water and a salt PS/Chem.–Jan. ’11 235 92 U [4] Part B–1 Answer all questions in this part. Directions (31–50): For each statement or question, write in your answer booklet the number of the word or expression that, of those given, best completes the statement or answers the question. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 31 Which electron configuration represents the electrons of an atom in an excited state? (1) 2-1 (3) 2-8-7 (2) 2-7-4 (4) 2-4 38 Which statement describes the general trends in electronegativity and metallic properties as the elements in Period 2 are considered in order of increasing atomic number? (1) Both electronegativity and metallic properties decrease. (2) Both electronegativity and metallic properties increase. (3) Electronegativity decreases and metallic properties increase. (4) Electronegativity increases and metallic properties decrease. 32 What is the total number of neutrons in an atom of O-18? (1) 18 (3) 10 (2) 16 (4) 8 33 What is the net charge of an ion that has 8 protons, 9 neutrons, and 10 electrons? (1) 1+ (3) 1− (2) 2+ (4) 2− 39 Which balanced equation represents a singlereplacement reaction? (1) Mg + 2AgNO3 → Mg(NO3)2 + 2Ag (2) 2Mg + O2 → 2MgO (3) MgCO3 → MgO + CO2 (4) MgCl2 + 2AgNO3 → 2AgCl + Mg(NO3)2 34 Which element is malleable and a good conductor of electricity at STP? (1) argon (3) iodine (2) carbon (4) silver 40 Given the balanced equation representing a reaction: 35 Which element has chemical properties that are most similar to the chemical properties of sodium? (1) beryllium (3) lithium (2) calcium (4) magnesium Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g) 36 If an element, X, can form an oxide that has the formula X2O3, then element X would most likely be located on the Periodic Table in the same group as (1) Ba (3) In (2) Cd (4) Na This reaction occurs more quickly when powdered iron is used instead of a single piece of iron of the same mass because the powdered iron (1) acts as a better catalyst than the single piece of iron (2) absorbs less energy than the single piece of iron (3) has a greater surface area than the single piece of iron (4) is more metallic than the single piece of iron 37 What is the total mass of KNO3 that must be dissolved in 50. grams of H2O at 60.°C to make a saturated solution? (1) 32 g (3) 64 g (2) 53 g (4) 106 g 41 The temperature of a sample of water changes from 10°C to 20°C when the sample absorbs 418 joules of heat. What is the mass of the sample? (1) 1 g (3) 100 g (2) 10 g (4) 1000 g PS/Chem.–Jan. ’11 [5] [OVER] 42 Given the reaction at 101.3 kilopascals and 298 K: hydrogen gas + iodine gas → hydrogen iodide gas This reaction is classified as (1) endothermic, because heat is absorbed (2) endothermic, because heat is released (3) exothermic, because heat is absorbed (4) exothermic, because heat is released 43 Given the equation: H H C H H + C H H C H H + C H C H C H H H H H H H H C C C C C C H H H H H H Which type of reaction is represented by this equation? (1) combustion (3) polymerization (2) esterification (4) substitution 44 The graph below represents the uniform heating of a sample of a substance starting as a solid below its melting point. F D E B C A Time (min) Which statement describes what happens to the energy of the particles of the sample during time interval DE? (1) Average kinetic energy increases, and potential energy remains the same. (2) Average kinetic energy decreases, and potential energy remains the same. (3) Average kinetic energy remains the same, and potential energy increases. (4) Average kinetic energy remains the same, and potential energy decreases. PS/Chem.–Jan. ’11 [6] 45 Which molecule has a nonpolar covalent bond? H H (1) H N H (2) H H O H H 48 The table below gives information about four aqueous solutions at standard pressure. Cl Four Aqueous Solutions (3) (4) 46 Given the equation representing a reaction at equilibrium: Aqueous Solution Concentration (M) A 2.0 BaCl2 Solute B 2.0 N2(g) + 3H2(g) 2NH3(g) NaNO3 C 1.0 C6H12O6 What occurs when the concentration of H2(g) is increased? D 1.0 K2SO3 (1) The equilibrium shifts to the left, and concentration of N2(g) decreases. (2) The equilibrium shifts to the left, and concentration of N2(g) increases. (3) The equilibrium shifts to the right, and concentration of N2(g) decreases. (4) The equilibrium shifts to the right, and concentration of N2(g) increases. the Which list of solutions is arranged in order from highest boiling point to lowest boiling point? (1) A, B, D, C (3) C, D, B, A (2) A, C, B, D (4) D, B, C, A the the 49 What is the total number of years that must pass before only 25.00 grams of an original 100.0-gram sample of C-14 remains unchanged? (1) 2865 y (3) 11 460 y (2) 5730 y (4) 17 190 y the 47 Which ionic equation is balanced? (1) Fe3+ + Al → Fe2+ + Al3+ (2) Fe3+ + 3Al → Fe2+ + 3Al3+ (3) 3Fe3+ + Al → 3Fe2+ + Al3+ (4) 3Fe3+ + Al → Fe2+ + 3Al3+ PS/Chem.–Jan. ’11 50 Which radioisotope is used for diagnosing thyroid disorders? (1) U-238 (3) I-131 (2) Pb-206 (4) Co-60 [7] [OVER] Part B–2 Answer all questions in this part. Directions (51–65): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. 51 Explain, in terms of electronegativity difference, why the bond in a molecule of HF is more polar than the bond in a molecule of HI. [1] 52 Explain, in terms of activity, why HCl(aq) reacts with Zn(s), but HCl(aq) does not react with Cu(s). [1] 53 Copper has two naturally occurring isotopes. Information about the two isotopes is shown in the table below. Naturally Occurring Isotopes of Copper Isotope Atomic Mass (atomic mass units, u) Percent Natural Abundance (%) Cu-63 62.93 69.17 Cu-65 64.93 30.83 In the space in your answer booklet, show a numerical setup for calculating the atomic mass of copper. [1] Base your answers to questions 54 and 55 on the information below. In an experiment, 2.54 grams of copper completely reacts with sulfur, producing 3.18 grams of copper(I) sulfide. 54 Determine the total mass of sulfur consumed. [1] 55 Write the chemical formula of the compound produced. [1] PS/Chem.–Jan. ’11 [8] Base your answers to questions 56 and 57 on the information below. Physical Properties of CF4 and NH3 at Standard Pressure Compound Melting Point (°C) Boiling Point (°C) Solubility in Water at 20.0°C CF4 −183.6 −127.8 insoluble NH3 −77.7 −33.3 soluble 56 State evidence that indicates NH3 has stronger intermolecular forces than CF4. [1] 57 In the space in your answer booklet, draw a Lewis electron-dot diagram for CF4. [1] Base your answers to questions 58 and 59 on the information below. A 2.0-liter aqueous solution contains a total of 3.0 moles of dissolved NH4Cl at 25°C and standard pressure. 58 Determine the molarity of the solution. [1] 59 Identify the two ions present in the solute. [1] PS/Chem.–Jan. ’11 [9] [OVER] Base your answers to questions 60 and 61 on the information below. Potential Energy The chemical reaction between methane and oxygen is represented by the potential energy diagram and balanced equation below. B C D A E Reaction Coordinate CH4(g) + 2O2(g) → CO2(g) + 2H2O(ℓ) + 890.4 kJ 60 Which potential energy interval in the diagram represents the activation energy of the forward reaction? [1] 61 Explain, in terms of collision theory, why a lower concentration of oxygen gas decreases the rate of this reaction. [1] PS/Chem.–Jan. ’11 [10] Base your answers to questions 62 and 63 on the information below. The diagram and balanced ionic equation below represent a voltaic cell with copper and silver electrodes and the reaction that occurs when the cell is operating. Voltaic Cell V Voltmeter Wire Wire Salt bridge Cu(s) electrode Cu2+(aq) Ag(s) electrode Ag+(aq) Cu(s) + 2Ag+(aq) Cu2+(aq) + 2Ag(s) 62 Describe the direction of electron flow in the external circuit in this operating cell. [1] 63 State the purpose of the salt bridge in this voltaic cell. [1] Base your answers to questions 64 and 65 on the information below. A 20.0-milliliter sample of HCl(aq) is completely neutralized by 32.0 milliliters of 0.50 M KOH(aq). 64 Calculate the molarity of the HCl(aq). Your response must include both a numerical setup and the calculated result. [2] 65 According to the data, to what number of significant figures should the calculated molarity of the HCl(aq) be expressed? [1] PS/Chem.–Jan. ’11 [11] [OVER] Part C Answer all questions in this part. Directions (66–83): Record your answers in the spaces provided in your answer booklet. Some questions may require the use of the Reference Tables for Physical Setting/Chemistry. Base your answers to questions 66 through 68 on the information below. In the early 1800s, John Dalton proposed an atomic theory that was based on experimental observations made by several scientists. Three concepts of Dalton’s atomic theory are stated below. Statement A: Atoms are indivisible and cannot be destroyed or broken down into smaller parts. Statement B: Atoms of one element cannot be changed into atoms of another element. Statement C: All atoms of one element have the same mass. 66 Explain, in terms of particles, why statement A is no longer accepted. [1] 67 The decay of N-16 is represented by the balanced equation below. 16 7N → 0 −1 e + 16 8O State evidence that indicates statement B is not always true. [1] 68 Explain, in terms of particles in the atoms of an element, why statement C is false. [1] Base your answers to questions 69 through 71 on the information below. A tablet of one antacid contains citric acid, H3C6H5O7, and sodium hydrogen carbonate, NaHCO3. When the tablet dissolves in water, bubbles of CO2 are produced. This reaction is represented by the incomplete equation below. H3C6H5O7(aq) + 3NaHCO3(aq) → Na3C6H5O7(aq) + 3CO2(g) + 3 _______ (ℓ) 69 Complete the equation in your answer booklet by writing the formula of the missing product. [1] 70 State evidence that a chemical reaction occurred when the tablet was placed in the water. [1] 71 Determine the total number of moles of sodium hydrogen carbonate that will completely react with 0.010 mole of citric acid. [1] PS/Chem.–Jan. ’11 [12] Base your answers to questions 72 through 74 on the information below. Cold packs are used to treat minor injuries. Some cold packs contain NH4NO3(s) and a small packet of water at room temperature before activation. To activate this type of cold pack, the small packet must be broken to mix the water and NH4NO3(s). The temperature of this mixture decreases to approximately 2°C and remains at this temperature for 10 to 15 minutes. 72 State the direction of heat flow that occurs when the activated cold pack is applied to the body. [1] 73 Identify both types of bonds in the NH4NO3(s). [1] 74 Identify the type of mixture formed when the NH4NO3(s) is completely dissolved in the water. [1] Base your answers to questions 75 through 77 on the information below. Litharge, PbO, is an ore that can be roasted (heated) in the presence of carbon monoxide, CO, to produce elemental lead. The reaction that takes place during this roasting process is represented by the balanced equation below. PbO(s) + CO(g) → Pb(ℓ) + CO2(g) 75 Write the balanced equation for the reduction half-reaction that occurs during this roasting process. [1] 76 Determine the oxidation number of carbon in carbon monoxide. [1] 77 Calculate the percent composition by mass of oxygen in litharge (gram-formula mass = 223.2 grams per mole). Your response must include both a numerical setup and the calculated result. [2] PS/Chem.–Jan. ’11 [13] [OVER] Base your answers to questions 78 through 80 on the information below. In one industrial organic reaction, C3H6 reacts with water in the presence of a catalyst. This reaction is represented by the balanced equation below. H H H H H C C C H H C C H H C H + H2O catalyst H OH H H 78 Explain, in terms of bonding, why C3H6 is classified as an unsaturated hydrocarbon. [1] 79 Write the IUPAC name for the organic reactant. [1] 80 Identify the class of compound to which the product of the reaction belongs. [1] Base your answers to questions 81 through 83 on the information below. A student, wearing chemical safety goggles and a lab apron, is to perform a laboratory test to determine the pH value of two different solutions. The student is given one bottle containing a solution with a pH of 2.0 and another bottle containing a solution with a pH of 5.0. The student is also given six dropping bottles, each containing a different indicator listed in Reference Table M. 81 State one safety precaution, not mentioned in the passage, that the student should take while performing tests on the samples from the bottles. [1] 82 Identify an indicator in Reference Table M that would differentiate the two solutions. [1] 83 Compare the hydronium ion concentration of the solution having a pH of 2.0 to the hydronium ion concentration of the other solution given to the student. [1] PS/Chem.–Jan. ’11 [14] The University of the State of New York REGENTS HIGH SCHOOL EXAMINATION PHYSICAL SETTING CHEMISTRY Thursday, January 27, 2011 — 1:15 to 4:15 p.m., only ANSWER BOOKLET Student . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Male Sex: I Female Teacher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . School . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Score Part A 30 B–1 20 B–2 16 C 19 Student’s Score Total Written Test Score (Maximum Raw Score: 85) Final Score (from conversion chart) Grade . . . . . . . . . Raters’ Initials: Answer all questions in this examination. Record your answers in this booklet. Rater 1 . . . . . . . . . . Rater 2 . . . . . . . . . . Part B–1 Part A 1 ............ 11 . . . . . . . . . . . . 21 . . . . . . . . . . . . 31 . . . . . . . . . . . . 41 . . . . . . . . . . . . 2 ............ 12 . . . . . . . . . . . . 22 . . . . . . . . . . . . 32 . . . . . . . . . . . . 42 . . . . . . . . . . . . 3 ............ 13 . . . . . . . . . . . . 23 . . . . . . . . . . . . 33 . . . . . . . . . . . . 43 . . . . . . . . . . . . 4 ............ 14 . . . . . . . . . . . . 24 . . . . . . . . . . . . 34 . . . . . . . . . . . . 44 . . . . . . . . . . . . 5 ............ 15 . . . . . . . . . . . . 25 . . . . . . . . . . . . 35 . . . . . . . . . . . . 45 . . . . . . . . . . . . 6 ............ 16 . . . . . . . . . . . . 26 . . . . . . . . . . . . 36 . . . . . . . . . . . . 46 . . . . . . . . . . . . 7 ............ 17 . . . . . . . . . . . . 27 . . . . . . . . . . . . 37 . . . . . . . . . . . . 47 . . . . . . . . . . . . 8 ............ 18 . . . . . . . . . . . . 28 . . . . . . . . . . . . 38 . . . . . . . . . . . . 48 . . . . . . . . . . . . 9 ............ 19 . . . . . . . . . . . . 29 . . . . . . . . . . . . 39 . . . . . . . . . . . . 49 . . . . . . . . . . . . 10 . . . . . . . . . . . . 20 . . . . . . . . . . . . 30 . . . . . . . . . . . . 40 . . . . . . . . . . . . 50 . . . . . . . . . . . . Part B–1 Score Part A Score The declaration below must be signed when you have completed the examination. I do hereby affirm, at the close of this examination, that I had no unlawful knowledge of the questions or answers prior to the examination and that I have neither given nor received assistance in answering any of the questions during the examination. Signature For Raters Only Part B–2 51 51 52 52 53 53 54 g 54 55 55 [2] For Raters Only 56 56 57 57 58 M 58 59 __________________________________ and ___________________________________ 59 60 60 61 61 [3] [OVER] For Raters Only 62 62 63 63 64 64 M 65 65 Total Score for Part B–2 [4] For Raters Only Part C 66 66 67 67 68 68 69 H3C6H5O7(aq) + 3NaHCO3(aq) → Na3C6H5O7(aq) + 3CO2(g) + 3 ___________________(ℓ ) 69 70 70 71 mol 71 72 72 73 ________________________________ and ___________________________________ 73 74 _________________________________ 74 [5] [OVER] For Raters Only 75 _________________________________ 75 76 76 77 77 % 78 78 79 _________________________________ 79 80 _________________________________ 80 81 81 82 _________________________________ 82 83 83 Total Score for Part C [6]