Name_________________________May 8, 2006General InstructionsCHEM 160-01 Practice Final Exam (150 points) Name _________________________ May 8, 2006 General Instructions 1. The format of this exam is 75 multiple-choice questions, 2 points each. There is only one correct answer to each question. If you make a mistake, completely erase your mistake. If you fail to erase your first answer, you will not receive credit for the problem. NO partial question will be awarded, so there is no penalty for guessing. 2. Useful constants: 1 amu = 1.66054 × 10-27 kg 1 atm = 760 Torr = 760 mm Hg Boltzmann constant (k) = 1.38065 × 10-23 J K-1 Gas constant (R) = 0.08205 L atm mole-1 K-1 = 8.31447 J mole-1 K-1 Avogadro’s number (Na) = 6.02214 × 1023 mole-1 Ion Product of Water (Kw) = 1.000 × 10-14 at 25.0 °C Faraday constant (F) = 96,485 C mole-1 RT/F = 0.0257 V at 25°C 3. Assume a temperature of 298 K unless otherwise specified. 4. A useful exam strategy is to look over the entire exam briefly when you receive it and to work the problems or questions that you know how to do first. Then go back and try the questions that you are not so certain you know how to work. 5. A periodic table and table of standard reduction potentials are attached to the end of the exam for your reference. 6. Some common ions and their charges are: F-, fluoride S2O32-, thiosulfate Cl-, chloride C2O42-, oxalate Br-, bromide CN-, cyanide I-, iodide SCN-, thiocyanate NO3-, nitrate ClO4-, perchlorate NO2-, nitrite SO32-, sulfite SO42-, sulfate edta4-, ethylenediaminetetraacetate Page 1MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1. Which one of the following substances should exhibit hydrogen bonding in the liquid state? A. PH3 B. H2 C. H2S D. CH4 E. NH3 2. Which of the following substances should have the highest boiling point? A. CH4 B. Cl2 C. Kr D. CH3Cl E. N2 3. Which of the following liquids would have the highest viscosity at 25ºC? A. CH3OCH3 B. CH2Cl2 C. C2H5OH D. CH3Br E. HOCH2CH2OH 4. Which of the following properties indicates the presence of weak intermolecular forces in a liquid? A. a high heat of vaporization B. a high critical temperature C. a high vapor pressure D. a high boiling point E. None of the above. Page 25. Which of the following would be expected to have the lowest vapor pressure at room temperature? A. ethanol bp = 78°C B. methanol bp = 65°C C. water bp = 100°C D. acetone bp = 56°C 6. Arrange the following in order of increasing boiling point: RbCl, CH3Cl, CH3OH, CH4. A. CH3OH < CH3Cl < RbCl < CH4 B. CH3OH < CH4 < CH3Cl < RbCl C. RbCl < CH3Cl < CH3OH < CH4 D. CH4 < CH3OH < CH3Cl < RbCl E. CH4 < CH3Cl < CH3OH < RbCl 7. Which of the following atoms does NOT participate in hydrogen bonding? A. S B. O C. F D. N 8. The number of atoms in a face-centered cubic unit cell is A. 1 B. 2 C. 3 D. 4 E. 8 9. A liquid boils when its A. vapor pressure is exactly 1 atmosphere. B. vapor pressure is equal to, or greater than, the external pressure pushing on it. C. temperature is equal to 273 K (standard temperature). D. temperature is greater than room temperature. Page 310. The heat capacity for liquid water is 4.18 J/g•°C and the heat of vaporization ( ) is 40.7 kJ/mol. How many kilojoules (kJ) of heat must be provided to convert one gram of liquid water at 67°C into one gram of steam at 100°C? ovapH∆ A. 22.6 kJ B. 40.8 kJ C. 2.2 kJ D. 2,400 J E. 40.8 J 11. Which of the following is NOT an endothermic process? A. melting of a solid B. vaporization C. raising the temperature of a gas D. condensation of water vapor E. sublimation of dry ice 12. The vapor pressure of ethanol is 400 mmHg at 63.5°C. Its molar heat of vaporization () is 39.3 kJ/mol. What is the vapor pressure of ethanol, in mmHg ,at 34.9°C? ovapH∆ A. 1,510 mmHg B. 100 mmHg C. 200 mmHg D. 0.0099 mmHg E. 4.61 mmHg 13. The reaction A + 2B → products was found to follow the rate law: rate = k[A]2[B]. Predict by what factor the rate of reaction will increase when the concentration of A is doubled and the concentration of B is tripled, and the temperature remains constant. A. 5 B. 6 C. 12 D. 18 E. None of the above. Page 414. Nitric oxide reacts with hydrogen to form nitrous oxide, and water. Use the following data to determine the rate law for the reaction. 22 22NO H N O H O+→ +Expt. # []0NO []20H Initial rate 1 0.021 0.065 1.46 M/min 2 0.021 0.260 1.46 M/min 3 0.042 0.065 5.84 M/min A. rate = k[NO] B. rate = k[NO]2 C. rate = k[NO][H2] D. rate = k[NO]2[H2] E. rate = k[NO]2[H2]2 15. A certain first-order reaction A → B is 25% complete in 42 min at 25°C. What is the half-life of the reaction? A. 21 min B. 42 min C. 84 min D. 101 min E. 120 min 16. A first-order reaction has a rate constant of 3.0 × 10–3/s. The time required for the reaction to be 75% complete is: A. 95.8 s B. 201 s C. 231 s D. 462 s E. 41.7 s 17. The activation energy for the following reaction is 60 kJ/mol. By what factor (how many times) will the rate constant increase when the temperature is raised from 10°C to 28°C? 234+Sn 2Co Sn 2Co+++→+2+ A. 1.002 B. 4.6 C. 5.6 D. 2.8 E. 696 Page 518. When the concentrations of reactant molecules are increased, the rate of reaction increases. The best explanation is: As the reactant concentration increases; A. the average kinetic energy of molecules increases. B. the frequency of molecular collisions increases. C. the rate constant increases. D. the activation energy increases. E. the order of reaction increases. 19. Which is the correct equilibrium constant expression for the following reaction? 23 2 2Fe O (s) 3H (g) 2Fe(s) 3H O(g)+⇔+ A. [][[][ ]]323 2c232Fe O HKFe H O= B. [][]2c2HKHO= C. [][]32c32HHO=K D. [][][][]232c323 2Fe H OKFe O H= E. [][][][]2c23 2Fe H OKFe O H= 20. Which of the following is a true statement about chemical equilibria in general? A. At equilibrium, the total concentration of products equals the total concentration of reactants, that is [products] = [reactants]. B. Equilibrium is the result of the cessation of