Download AP Chem -‐ Unit 1 Part 1 AP Chemistry 2016

AP Chem -­‐ Unit 1 Part 1 AP Chemistry 2016-­‐2017 Unit 1: Measurement, Matter, and Stoichiometry (Ch. 1-­‐3) After completion of unit 1 I will be able to… • Identify an element or determine its purity using mass percent calculations. • Use mole relationships to convert between moles, mass and particles. • Balance chemical reactions and use mole ratios to predict amounts needed or produced in a chemical reaction. • Identify different properties of solids and liquids based on both differences in structure at both a particle and macro level. • Identify and name ionic compounds. • Identify and name molecular compounds. • Calculate a reactions percent yield taking into account limiting and excess reactants. • Determine the empirical formula of a substance from lab data. • Classify a reaction as a chemical, physical or ambiguous change. • Identify the difference between a chemical and physical change based on inter and intra molecular forces. *Note the above list is not an exhaustive list. (see topic check list for more support) Ch. 1 Measurement SI Units Conversions Example Problem 1: The diameter of a helium atom is about 30 pm. Write this length using exponential notation with units of m. (A: 3 x 10-­‐11 m) AP Chem -­‐ Unit 1 Part 1 Example Problem 2: Is a lady speeding if she is going 90 km/hr and the speed limit is 60 mi/hr? (1.0 mi = 1.6 km) (A: no; 56 mph) Practice Problems: Dimensional Analysis 1. Michael Oher (offensive tackle for the Baltimore Ravens and subject of the movie The Blind Side) has a mass of 141,000 grams. What is his mass in lbs? (1.00 kg = 2.20 lbs) (A: 310. lbs) 2. You are the purchasing agent at a start-­‐up biotechnology firm. If sucrose costs $1.20 per pound, and a bottle contains 2.00 kg, how much would you pay for a case of sucrose containing 12 bottles? (A: $63.36) 3. You will need the following information helpful in solving the problem below. sodium fluoride (NaF) is 45.0% fluoride by mass 1 ppm means “one part per million by mass (i.e. 1 g of fluoride per one million grams of water) 1 gallon = 3.79 liters 1 year = 365.25 days 1 ton = 2000. lbs 1 lb = 453.6 g density of water = 1.00 g/mL You are a public health officer in the water treatment facility for a city of 50,000 people. A concentration of 1.0 ppm of fluoride in the drinking water is sufficient for the purpose of helping to prevent tooth decay. The compound normally chosen for fluoridation is the same as is found in some toothpastes, sodium fluoride (NaF). Calculate how many tons of sodium fluoride you will need to purchase in order to fluoridate the city’s water supply for one year, based on your estimate that the average daily consumption of water is 150 gallons per person. (A: 25.4 tons) Temperature Conversions: Example Problem 3: Liquid nitrogen, which is often used as a coolant for low-­‐temperature experiments, has a boiling point of 77 K. What is this temperature on the Celsius scale? (A: -­‐196°C) AP Chem -­‐ Unit 1 Part 1 Derived SI Units Volume: Density: Example Problem 4: A chemist, trying to identify the main component of a compact disc cleaning fluid, finds that 25.00 mL of the substance has a mass of 19.625 g at 20.00°C. The following are the names and densities of the compounds that might be the main component: Compound Density in g/cm3 at 20°C Chloroform 1.492 Diethyl ether 0.714 Ethanol 0.789 Isopropyl alcohol 0.785 Toluene 0.867 Which of these compounds is the most likely to be the main component of the compact disc cleaner? (A: density=0.7850 g/cm3; isopropyl alcohol) Uncertainty in Measurement Precision and Accuracy: Significant Figures (Sig Figs) and Calculations RULES Example Problem 5: Give the number of significant figures for each of the following results. a. A student’s extraction procedure on tea yield’s 0.0105 g of caffeine. b. A chemist records a mass of 0.050080 g in an analysis. c. In an experiment a span of time is determined to be 8.050 x 10-­‐3 s. Example Problem 6: Carry out the following mathematical operations, and give each result with the proper units and the correct number of significant figures. a. 1.05 x 10-­‐3 g ÷ 6.135 L (A: 1.71 x 10-­‐4 g/L) b. 21 cg – 13.8 cg (A: 7 cg) c. As part of a lab assignment to determine the value of the gas constant (R), a student measures the number of moles (n), pressure (P), volume (V), and temperature (T) for a sample of gas, where PV = nRT AP Chem -­‐ Unit 1 Part 1 The following values were obtained: n = 1.00 mol; P = 2.560 atm; T = 275.15 K; and V = 8.8 L. Calculate R to the correct number of significant figures and use proper labels. (A: 0.082 atm·∙L/mol·∙K) Ch. 1 Classification of Matter Matter: States of Matter Solid: Liquid: Gas: Pure Substances Elements Examples: Compounds Examples: Mixtures Homogeneous Examples: Heterogeneous Examples: Separation of Mixtures (will discuss more in later unit) AP Chem -­‐ Unit 1 Part 1 **Recommended practice chapter problems with odd number answers provided in back of book. End of chapter (after page 41) AP MC Review Questions(1-­‐10) – Solutions (PRACTICE THESE!) 1. c 2. c 3. a 4. b 5. a 6.b 7.c 8.d 9.d 10.b Ch. 2 Matter (Atoms, Molecules and Ions) The Early History of Atomic Theories (know the impact of the following scientists…) Democritus (460-­‐370 BC) John Dalton (1807) J.J. Thomson (1897) Robert Millikan (1909) Ernest Rutherford (1911) James Chadwick (1932) Fundamental Chemical Laws Law of Conservation of Mass (Antoine Lavoisier, 1743-­‐1794) Law of Definite Proportion (Joseph Proust, 1754-­‐1826) Law of Multiple Proportions (John Dalton, 1766-­‐1844) Example Problem 7: The following data were collected for several compounds of nitrogen and oxygen: Mass of Nitrogen That Combines with 1 gram Oxygen Compound A 1.750 g Compound B 0.8750 g Compound C 0.4375 g Show how these data illustrate the law of multiple proportions. AP Chem -­‐ Unit 1 Part 1 Atoms, Isotopes, and Ions – An Introduction to the Modern View of Atomic Structure Subatomic Particles Proton Neutron Electron Isotopes Atomic Number Mass Number Ion Charge Cation Anion Writing symbols for atoms Example Problem 8: Write the symbol for the atom that has the atomic number of 9 and a mass number of 19. How many protons, neutrons, and electrons does this atom have? Average Atomic Mass Calculations Example Problem 9: When a sample of natural copper is vaporized and injected into a mass spectrometer, the results show the sample is 69.09% copper-­‐63 and 30.91% copper-­‐65. Use these data to compute the average mass of natural copper. (The mass values for 63Cu and 65Cu are 62.93 amu and 64.93 amu, respectively.) X AP Chem -­‐ Unit 1 Part 1 The Periodic Table Metals, Nonmetals, and Metalloids Groups and Families Alkali metals Alkaline earth metals Transition metals Halogens Noble gases Lanthanides Actinides Periods Molecules and Molecular Compounds Covalent Bonds Chemical Formula Structural Formula / Line Drawing (more with VSEPR to come later) Ions and Ionic Compounds Ionic Bonds Cations and Anions Polyatomic Ions (See list) – Memorize! AP Chem -­‐ Unit 1 Part 1 Naming Simple Inorganic Compounds Binary Ionic Compounds (Stock System) Example Problem 10: Name each binary ionic compound. a. CsF b. AlCl3 c. LiH d. CuCl e. HgO f. Fe2O3 g. MnO2 h. PbCl2 i. CoBr2 j. CaCl2 k. Al2O3 l. CrCl3 Compounds Containing Polyatomic Ions Example Problem 11: Give the systematic name of each of the following compounds. a. Na2SO4 b. KH2PO4 c. Fe(NO3)3 d. Mn(OH)2 e. Na2SO3 f. Na2CO3 g. NaHCO3 h. CsClO4 i. NaOCl Binary Covalent Compounds AP Chem -­‐ Unit 1 Part 1 Example Problem 12: Name each of the following compounds. a. PCl5 b. PCl3 c. SF6 d. SO3 e. SO2 f. CO2 g. P4O10 h. Li2O2 i. Ti(NO3)4 Example Problem 13: Given the following systematic names, write the formula for each compound. a. vanadium (V) fluoride b. dioxygen difluoride c. rubidium peroxide d. gallium oxide Acids (more to come with this later too) Binary Acids Oxy-­‐acids Example Problem 14: Name each of the following compounds. a. HF b. HNO3 c. HNO2 d. HClO4 e. HClO3 f. HClO2 g. HClO h. HC2H3O2 AP Chem -­‐ Unit 1 Part 1 i. HCN j. H2S Hydrated Salts Example Problem 15: Name each of the following compounds. a. BaCl2·∙2H2O b. LiCl·∙H2O c. MgSO4·∙7H2O d. Sr(NO3)2·∙4H2O End of the chapter (after page 80) AP MC Review Questions (1-­‐16) Solutions (PRACTICE THESE) 1. a, 2. b, 3. a, 4. d, 5. a, 6. d, 7. c, 8. b, 9. c, 10. c, 11. a, 12. d, 13. c, 14. b, 15. d, 16. b AP CHEMISTRY UNIT 1 REVIEW (Chapters 1 & 2) 1. 2. 3. 4. 5. 6. 7. 8. Perform the following mathematical operations, and express each result to the correct number of significant figures and units. a. 97.381 cm + 4.2502 cm + 0.99195 cm b. (9.2 µm x 100.65 µm) / (8.321 mL + 4.026 mL) 6
-­‐7
c. 2.00 x 10 cg / 3.00 x 10 hL A rectangular solid measures 1.0 m by 5.6 cm by 2.1dm. Express its volume in cubic meters, liters, cubic inches and cubic feet. The density of pure silver is 10.5 g/cm3 at 20ºC. If 5.25 g of pure silver pellets is added to a graduated cylinder containing 11.2 mL of water, to what volume level will the water in the cylinder rise? Classify the following as physical or chemical changes. a. Moth balls gradually vaporize in a closet. b. Hydrofluoric acid attacks glass, and is used to etch calibration marks on glass laboratory utensils. c. A French chef making a sauce with brandy is able to burn off the alcohol from the brandy, leaving just the brandy flavoring. d. Chemistry majors sometimes get holes in their cotton jeans they wear to lab because of acid spills. Complete the following table: Symbol Protons 33 128
2-­‐
Te 16 81 195
Pt Neutrons 42 16 123 Electrons 16 Which of the following sets of elements are all in the same group in the periodic table? a. Fe, Ru, Os c. Sn, As, S b. Rh, Pd, Ag d. Se, Te, Po Name each of the following compounds. a. Rb2O f. S4N4 b. Hg2O g. NaOCl c. NH4NO2 h. SnO2 d. ICl i. SO2 e. H2SO4 j. Co2S3 Write the formulas for each of the following compounds. Net charge 3+ 1+ AP Chem -­‐ Unit 1 Part 1 a. b. c. d. e. sulfur difluoride lithium nitride mercury (I) chloride diphosphorus pentoxide potassium cyanide f. g. h. i. j. sodium dihydrogen phosphate chromium (III) carbonate nitrous acid copper (II) sulfate pentahydrate cadmium selenide Marathon Problem: A cylindrical bar of gold that is 1.5 m high and 0.25 in. in diameter has a mass of 23.1984 g, as determined on an analytical balance. An empty graduated cylinder is weighed on a triple-­‐beam balance and has a mass of 73.47 g. After pouring a small amount of liquid into the graduated cylinder, the mass is 79.16 g. When the gold cylinder is placed in the graduated cylinder (the liquid covers the top of the gold cylinder), the volume indicated on the graduated cylinder is 8.5 mL. Assume the temperature of the gold bar and the liquid are 86°F. If the density of the liquid decreases by 1.0% for each 10°C rise in temperature (over the range 0°C to 50°C), determine a. the density of the gold at 86°F. b. the density of the liquid at 40°F. Answers: 1. a. 102.623 cm b. 75 µm2/mL c. 6.67 x 1012 cg/hL 2. 1.2 x 10-­‐2 m3; 12 L; 730 in3; 0.42 ft3 3. The volume will rise to 11.7 mL 4. a. physical b. chemical c. physical d. chemical 5. Symbol Protons Neutrons Electrons Net charge 75
As3+ 33 42 30 3+ 128
2-­‐
Te 52 76 54 2-­‐ 32
S 16 16 16 0 204 +
Tl 81 123 80 1+ 195
Pt 78 117 78 0 6. a and d 7. a. rubidium oxide b. mercury (I) oxide c. ammonium nitrite d. iodine monochloride e. sulfuric acid f. tetrasulfur tetranitride g. sodium hypochlorite h. tin (IV) oxide i. sulfur dioxide j. cobalt (III) sulfide 8. a. SF2 b. Li3N c. Hg2Cl2 d. P2O5 e. KCN f. NaH2PO4 g. Cr2(CO3)3 h. HNO2 i. CuSO4·∙5H20 j. CdSe UNIT 1 HOME LEARNING PROBLEMS AP Chem -­‐ Unit 1 Part 1 1. A solid white substance A is heated strongly in the absence of air. It decomposes to form a new white substance B and a gas C. The gas has exactly the same properties as the product obtained when carbon is burned in an excess of oxygen. Based on these observations, can we determine whether solids A and B and the gas C are elements or compounds? Justify your conclusions for each substance. 2. An experiment requires 45.0 g of ethylene glycol, a liquid whose density is 1.114 g/mL. Rather than weigh the sample on a balance, the chemist chooses to dispense the liquid using a graduated cylinder. What volume of liquid should the chemist use? 3. A cubic piece of metal measures 5.00 cm on each edge. If the metal is nickel, whose density ios 8.90 g/cm3, what is the mass of the cube? 4. What is the number of significant figures in each of the following measured quantities? (a) 358 kg (b) 0.054 s (c) 6.3050 cm (d) 0.0105 L (e) 7.0500 x 10-­‐3 m3 5. Carry out each of the following operations and express the answers with the appropriate number of significant figures. (a) 12.0550 + 9.05 = (b) 257.2 – 19.789 = (c) (6.21 x 103)(0.1050) = (d) 0.0577 / 0.753 = 6. Perform the following conversions (note: you might have to research some conversion factors): (a) The speed of light in a vacuum is 2.998 x 108 m/s. Calculate its speed in km/hr. (b) An individual suffering from high cholesterol level in her blood has 252 mg of cholesterol per 100 mL of blood. If the total blood volume of the individual is 5.2 L, how many grams of total blood cholesterol does the individual’s body contain? AP Chem -­‐ Unit 1 Part 1 (c) The recommended adult dose of Elixophyllin®, a drug used to treat asthma, is 6 mg per kg of body mass. Calculate the dose in a 150-­‐lb person. (d) A pound of coffee beans yields 50 cups of coffee (4 cups = 1 quart). How many milliliters of coffee can be obtained from 1 gram of coffee beans? 7. A 15.0-­‐cm long cylindrical glass tube, sealed at one end, is filled with ethanol. The mass of ethanol needed to fill the tube is found to be 11.86 g. The density of ethanol is 0.789 g/mL. Calculate the inner diameter of the tube in centimeters. 8. A 32.65-­‐g sample of a solid is placed in a flask. Toluene, in which the solid is insoluble, is added to the flask so that the total volume of solid and liquid together is 50.00-­‐mL. The solid and toluene together weigh 58.58 g. The density of toluene at the temperature of the experiment is 0.864 g/mL. What is the density of the solid? 9. Fill in the following table: Symbol Atomic Number Mass Number Protons Neutrons Electrons 25 30 25 19 21 18 133 55 54 Br 1-­‐ Zinc-­‐65 52 80
Cr 3+ 10. Three isotopes of silicon occur in nature. 92.23% occur as Silicon-­‐28 (which has an atomic mass of 27.97693 amu); 4.68% occur as silicon-­‐29 (which has and atomic mass of 28.97649 amu); and 3.09% occur as silicon-­‐30 (which has and atomic mass of 29.97377 amu). Calculate the atomic weight of silicon. 11. Predict the chemical formulas of the compounds formed by the following pairs of ions: (a) Cu2+ and Br-­‐ (b) Fe3+ and O2-­‐ (c) Hg22+ and CO32-­‐ (d) Ca2+ and AsO43-­‐ (e) NH4+ and SO42-­‐ AP Chem -­‐ Unit 1 Part 1 12. Predict whether each of the following compounds is molecular or ionic: (a) B2H6 (b) CH3OH (c) LiNO3 (d) Sc2O3 (e) CsBr (f) NOCl (g) Ag2SO4 13. Name the following ionic compounds: (a) MgO (b) AlCl3 (c) Li3PO4 (d) Ba(ClO4)2 (d) Cu(NO3)2 (e) Fe(OH)2 (f) Ca(C2H3O2)2 (g) Cr2(CO3)3 (h) K2CrO4 (i) (NH4)2SO4 14. Write the chemical formulas for the following compounds: (a) aluminum hydroxide (b) potassium sulfate (c) copper (I) oxide (d) zinc nitrate (e) mercury (II) bromide AP Chem -­‐ Unit 1 Part 1 (f) iron (III) carbonate (g) sodium iodate (h) barium perchlorate (i) potassium dichromate (j) cobalt (II) hydrogen carbonate (k) sodium peroxide 15. Give the name or chemical formula, as appropriate, for the following acids: (a) HBrO3 (b) HBr (c) H3PO4 (d) hypochlorous acid (e) iodic acid (f) sulfurous acid (g) hydrosulfuric acid (h) HClO3 (i) HC2H3O2 (j) nitrous acid 16. Give the name or chemical formula, as appropriate, for each of the following binary molecular compounds: (a) SF6 (b) IF5 (c) XeO3 (d) dinitrogen tetroxide (e) hydrogen cyanide (f) tetraphosphorus hexasulfide (g) N2O