Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chemical bond wikipedia , lookup
Metallic bonding wikipedia , lookup
Nucleophilic acyl substitution wikipedia , lookup
Stoichiometry wikipedia , lookup
Acid–base reaction wikipedia , lookup
Bioorthogonal chemistry wikipedia , lookup
Electron configuration wikipedia , lookup
Atomic theory wikipedia , lookup
Organosulfur compounds wikipedia , lookup
HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 1 of 14 NAME:______________________________ EXAM IR KEY OCTEBER 5 2001 CH 103 DIRECTIONS • There is only one correct answer to each question unless otherwise noted. Any questions for which more than one response has been selected will not be counted • Your score is based solely on the number of questions you answer correctly. It is to your advantage to answer every question. • The best strategy is to arrive at your own answer to a question before looking at the choices. Otherwise, you may be misled by plausible, but incorrect, responses. IF YOU SELECT “NONE OF THE ABOVE” as an answer, write your numerical answer, including units, next to it. YOUR SCORE FOR THE 1st HOUR EXAM WILL BE EITHER THE AVERAGE OF YOUR SCORE ON EXAM I & EXAM IR, OR YOUR SCORE ON EXAM I, WHICHEVER IS THE HIGHER. IF YOU FIND YOURSELF BAULKED BECAUSE THERE IS A PIECE OF INFORMATION YOU DON’T HAVE, RAISE YOUR HAND. YOU MAY BE ABLE TO BUY THE INFORMATION FOR A POINT. TAKE A DEEP BREATH AND LET YOUR EYES FOCUS. RELAX YOUR SHOULDERS WHEN IN DOUBT CONVERT TO MOLES! Page 1 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 2 of 14 Page 2 of 14 NAME:______________________________ POINTS THIS PAGE: _______ HOUR EXAM I NAME:______________________________ CHEM 103 SEPTEMBER 26 2001 Page 3 of 14 INORGANIC NOMENCLATURE: 1. Name, by IUPAC rules, the following compounds: a. sodium carbonate b. sulfuric acid ______Na2CO3 _____________________________ ____H2SO4____________________________ c. iron (III) sulfide ___Fe2S3___________________________ d. potassium hydroxide ___KOH______________________________ e. disulfur pentoxide __S2O5_______________________________ 5 pts: ____ 2. Give formulae for the following compounds: a. CoSO3: ____Cobalt (II) sulfite_____________________________ b. N2O: ________Dinitrogen monoxide________________ c. HI: _Hydroiodic acid or Hydrogen iodide______________________ d. NaF: __Sodium Fluoride___________________ e. Ba(OH)2: __Barium hydroxide_________________ 5 pts: ____ SHORT ANSWER: 1. DEFINE “ELECTRONEGATIVITY”:________________________________________________ The measure of the tendency of a combined atom to attract a shared pair of electrons to itself 10 Page 3 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 4 of 14 SHORT ANSWER: NAME:______________________________ 2. Draw the Lewis dot structure of the phosphate ion. Include resonance structures if appropriate. Predict the 3-D shape of the ion. 3PO4 5 + 4(6) + 3 = 32 e- MULTIPLE CHOICE PORTION (Each question is weighted at 5 points): 3. The force of electrostatic attraction between a phosphate ion and an aluminum ion is measured and found to be 2.077 x 10-13 N. Calculate the distance by which these two ions are separated: A B C D E 1.519E-14 m -1.000E-07 m 4.315E-40 m 1.000E-07 m None of the above 4. Which is FALSE about a. b. c. d. e. f. g. and They contain 56 & 57 neutrons respectively; They contain 42 protons, respectively; They are the elements Californium and Einsteinium; has two (2) MORE electrons than They are the element molybdenum; c and d are both false; b and e are both false. Page 4 of 14 POINTS THIS PAGE: _______ HOUR EXAM I NAME:______________________________ CHEM 103 SEPTEMBER 26 2001 Page 5 of 14 BONUS: True or false…all isotopes of carbon are radioactive. 5. A Helium nucleus, He2+, or -particle is produced when 222Rn decays. If it travels at 0.250 times the speed of light, calculate its kinetic energy. Atomic Wt He = 4.0026 g/mol A B C D E 1.65E-45 gcm2/sec2 1.86E-04 kgm2/sec2 1.86E-11 kgm2/sec3 1.12E+20 kgm2/sec4 None of the above 6. The correct Lewis structure for the barium ion is: A. Ba2+ B. C. D. E. 7. The barium ion is isoelectronic with (has the same # of electrons as): A. Radon B. Cesium ion C. Strontium D. Lanthanum E. Krypton BONUS: How many valence electrons do the ALKALI METALS have? ONE Page 5 of 14 POINTS THIS PAGE: _______ HOUR EXAM I NAME:______________________________ CHEM 103 SEPTEMBER 26 2001 Page 6 of 14 8. If the nucleus of an atom were about the size of a softball, the electrons, proportionally, would likely be found: a) Within the softball b) Within a foot of the nucleus; c) Somewhere in this room;; d) Somewhere between here and Winooski (about 2-3 km). e) Somewhere between here and Miami, FL. 9. Which of the following is MOST LIKELY to be an IONIC compound? A. B. C. D. Cesium chloride Sodium dicalcium Nitrogen trioxide Methane (CH4) 10. Which of the following is LEAST electronegative? A. Fluorine B. Hydrogen C. Francium D. Radon 11. A bright green ionic solid in an industrial stain remover is taken to the lab and analysed: ELEMENT Titanium Sulfur Oxygen % 24.95% 25.05% 50.00% ATOMIC WEIGHT (g/mol) 47.867 g/mol 32.066 g/mol 15.9994 g/mol The chemical formula is: A. B. C. D. TiSO2 Ti2S3O12 Ti4S4O8 Ti12S8O8 Page 6 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 7 of 14 NAME:______________________________ 12. The % by mass Cl in sodium chloride (NaCl) is: Atomic Wt Na = 22.99 g/mole Atomic Wt Cl = 35.5 g/mol HINT: (When in doubt, convert from moles to grams) A B C D E 35.5 % 64.8 % 60.7 % 154.4 % None of the above BONUS: Which of the following has the HIGHEST % by mass Cl? A. HCl B. KCl C. CsCl 13. Consider the reaction: Cu(s) + 4HNO3(aq) Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) If you start with 0.0200 g of copper metal and excess nitric acid, how many grams of copper(II)nitrate will you be able to make? Molecular & atomic weights: Cu Nitric acid Copper(II) nitrate Nitrogen dioxide water A B C D E 63.5 63.0 187.6 46.0 18.0 g/mol g/mol g/mol g/mol g/mol 2.00E-02 g 5.91E-02 g 1.07E-04 g 1.27E+00 g None of the above Page 7 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 8 of 14 14. Consider the reaction: SalH + Ac2O AcSal + HAc NAME:______________________________ O O C C C C C C C O C O H + CH 3 C O CH 3 O H O C C C C C C H O O + C C O H3C H O C O CH 3 If you start with 2.0010 g of salicyclic acid (SalH), how many grams of acetic anhydride (Ac2O) will you have to use to react with it completely? MW (g/mol) salicylic acid acetic anhydride acetyl salicylic acid A B C D E 138.12 102.09 180.16 2.71 g 204 g 0.74 g 1.48 g None of the above BONUS: How many significant figures are you allowed in the above problem? FIVE 15. Elements in Group VII of the periodic table: a) Tend to lose a single valence electron; b) Tend to gain two valence electrons; c) Have filled valence shells; d) Explode on contact with water. e) Are diatomic BONUS: Group VII elements are called: A. Chalcogens; B. Halogens C. Alkaline Earth Metals Page 8 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 9 of 14 NAME:______________________________ 15. The shape of the water (H2O) molecule is: A. Linear B. Bent at 90o C. Bent at 109o (Tetrahedral) D. Bent at 120o (Trigonal planr) 16. Consider the molecule CO. NAME IT: A. Carbon (IV) oxide B. Carbon monoxide monooxygen C. Carbon (II) oxide D. Carbon 17. Still considering CO, the electrons in the CO bond: A. Spend more time closer to O than C B. Spend equal time with C and O C. Spend more time closer to C than O D. CO is ionic, the electrons spend all their time with C and no time with O E. CO is ionic, the electrons spend all their time with C and no time with C Page 9 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 10 of 14 NAME:______________________________ For Q 18-19, consider the reaction: 3BaCl2 + 2Na3PO4 Ba3(PO4)2 + 6NaCl Suppose you start with 50.0 mmoles of barium chloride and 50.0 mmoles of sodium phosphate. 18. Which is the limiting reagent? A. BaCl2 B. Na3PO4 C. Ba3(PO4)2 D. NaCl 19. How many mmoles of sodium chloride will you make? A B C D E 100 mmoles 180 mmoles 50 mmoles 250 mmoles None of the above Page 10 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 11 of 14 20-21. Consider the reaction: NAME:______________________________ 2CH3NHNH2 + 5O2 2CO2 + 6H2O + 2N2 9.21 g of CH3NHNH2 reacts with 32.0 g of O2. MW (g/mol) mass (g) CH3NHNH2 46.1 g/mol 9.2 g O2 32.0 g/mol 32.0 g CO2 44.0 g/mol H2 O 18.0 g/mol N2 28.0 g/mol 20. Which is the limiting reagent? A. CH3NHNH2 B. O2 C CO2 D. H2O E. N2 21. How many grams of H2O will you make? A. B. C D. E. 0.200 g 41.2 g 10.8 g 21.6 g none of the above Bonus: Considering Q 20-21, if you actually manage to make 9.0 g of water in the lab, what is the % yield? Page 11 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 12 of 14 END OF EXAM! Page 12 of 14 NAME:______________________________ POINTS THIS PAGE: _______ HOUR EXAM I NAME:______________________________ CHEM 103 SEPTEMBER 26 2001 Page 13 of 14 SPECIAL UNITS & CONVERSION FACTORS Acceleration due to gravity (g) Avogadro’s number Bohr radius Boltzmann’s constant Electronic charge-to-mass ratio Elementary charge Faraday constant Gravitational constant (Universal) Mass of an electron Mass of a neutron Mass of a proton Molar volume of an ideal gas @ STP Permittivity of vacuum Planck’s constant Rydberg constant Speed of light in vacuo Universal gas constant Arrhenius Equarton g No ao kB -e/me e F G me Mn Mp Vm εo h R∞ c R 9.80665 m/sec2 6.0221367 x 1023 particles/mol 0.529177249 x 10-10 m 1.380658 x 10-23 J/K 1.75881962 x 1011 C/kg 1.60217733 x 10-19 C 9.6485309 x 104 C/mol 6.67259 x 10-11 m3/kg sec2 9.1093897 x 10-31 kg 1.6749286 x 10-27 kg 1.6726231 x 10-27 kg 22.41410 L/mol 8.854187817 x 10-12 C2/N m2 6.6260755 x 10-27 J sec 2.1798741 x 10-18 J 2.99792458 x 108 m/sec 8.314510 J/mol K 0.08205783 L atm/K mol k = Ae-Eact/RT Fgrav = -Gm1m2/r2 Felectrostatic = - [1/4πεo] q1 q2/r2 1 N = 1 kgm/sec2 1 J = 1 Nm = 1 kg m2/sec2 Page 13 of 14 POINTS THIS PAGE: _______ HOUR EXAM I CHEM 103 SEPTEMBER 26 2001 Page 14 of 14 NAME:______________________________ PERIODIC TABLE OF THE ELEMENTS 1A 1 H 8A 2 He 3 Li 2A 4 Be 3A 5 B 4A 6 C 5A 7 N 6A 8 O 7A 9 F 6.941 9.012 10.81 12.01 14.01 16.00 19.00 20.18 11 Na 12 Mg 5B 6B 7B 15 P 16 S 17 Cl 18 Ar 24.31 4B 14 Si 22.99 3B 13 Al 19 K 20 Ca 21 Sc 22 Ti 23 V 24 Cr 25 Mn 26 Fe 27 Co 39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 37 Rb 38 Sr 39 Y 40 Zr 41 Nb 42 Mo 43 Tc 44 Ru 85.47 87.62 88.91 91.22 92.91 95.94 (98) 55 Cs 56 Ba 57 La 72 Hf 73 Ta 74 W 75 Re 132.9 137.3 138.9 178.5 181.0 183.8 87 Fr 88 Ra 89 Ac 104 Unq 105 Unp 106 Unh (223) 226.0 227.0 (261) (262) 58 Ce 59 Pr 140.1 90 Th 232.0 1.008 10 Ne 1B 2B 26.98 28.09 30.97 32.07 35.45 39.95 28 Ni 29 Cu 30 Zn 31 Ga 32 Ge 33 As 34 Se 35 Br 36 Kr 58.93 58.69 63.55 65.39 69.72 72.61 74.92 78.96 79.90 83.80 45 Rh 46 Pd 47 Ag 48 Cd 49 In 50 Sn 51 Sb 52 Te 53 I 54 Xe 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 76 Os 77 Ir 78 Pt 79 Au 80 Hg 81 Tl 82 Pb 83 Bi 84 Po 85 At 86 Rn 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 (209) (210) (222) 107 Uns 108 Uno 109 Une (263) (262) (265) (266) 60 Nd 61 Pm 62 Sm 63 Eu 64 Gd 65 Tb 66 Dy 67 Ho 68 Er 69 Tm 70 Yb 71 Lu 140.9 144.2 (145) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0 91 Pa 92 U 93 Np 94 Pu 95 Am 96 Cm 97 Bk 98 Cf 99 Es 100 Fm 101 Md 102 No 103 Lr 231.0 238.0 237.0 (244) (243) (247) (247) (251) (252) (257) (258) (259) (260) Page 14 of 14 8B 4.003 POINTS THIS PAGE: _______