University of Kentucky - Department of Chemistry
1. Consider the reaction
2 C6H12 = C12H10 + 7 H2 If C6H12 is consumed at the rate of 0.050 M/s, at what rate is H2 formed?
A. 0.014 M/s B. 0.050 M/s C. 0.130 M/s D. 0.175 M/s
2. The reaction 2 A + 3 B = C is first order in A and zero order in B. The units for the rate constant, k, areA. L mol-1 s-1 B. s-1 C. mol L-1 s-1 D. L2 mol-2 s-1
3. If a reaction is second order in [A], what is the effect on the overall rate of tripling [A]?A. The rate stays the same. B. The rate is multiplied by a factor of 2. C. The rate is multiplied by a factor of 6. D. The rate is multiplied by a factor of 9.
4. The rate of the reaction A + 2 B = C has been observed at 25oC. From the following data, determine the rate law of the reaction.Exp. Initial [A](M) Initial [B](M) Initial rate (M/s) 1 0.100 0.100 5.5 x 10-6 2 0.200 0.100 2.20 x 10-5 3 0.100 0.300 1.65 x 10-5
A. rate = k[A]2[B] B. rate = k[B]3 C. rate = k[A][B]2 D. rate = k[A]2[B]o
5. Which of the following is false for a first order reaction?A. 1/[A]o = 1/[A] - kt. B. The slope of a plot of ln[A] against t is k. C. The half life is independent of the initial concentration of the reactant. D. Doubling the concentration of the reactant doubles the rate of the reaction.
6. The rate constant for the first-order decomposition of C4H8 at 500oC is 9.21 x 10-3 s-1. How long will it take for 20.0% of a sample of C4H8 to decompose at 500oC?A. 24.2 s B. 63.9 s C. 121 s D. 175 s
7. Consider the reaction
A + 2 B = products Which of the following mechanisms would correspond to a first order rate law?
A. A + B = C slow C + B = products fast
B. B + B = C fast C + A = products slow
C. A = C + D slow C + B = E fast D + B = F fast E + F = products fast
D. A + C = D slow D + 2 B = products + C fast
8. The activation energy is determined from a plot ofA. k vs. 1/T B. ln k vs. 1/T C. k vs. T D. ln k vs. T
9. Which of the following statements is false?A. A catalyst increases the rate of the reaction and increases the equilibrium constant. B. An intermediate is a molecule or ion that is formed during one elementary reaction step and consumed in a later step. C. Elementary steps involving three molecules or ions are rare. D. Most reaction mechanisms have more than one step.
10. Which of the following oxidation states for Mn is incorrect?A. MnO2, +4 B. MnO3+, +5 C. MnO4-, +7 D. MnCl2, +2
11. When the following reaction is balanced (in acidic solution), what is the ratio of Cu to NO3-?
Cu(s) + NO3-(aq) = Cu2+(aq) + NO(g) A. 1 Cu: 3 NO3- B. 2 Cu: 3 NO3- C. 3 Cu: 2 NO3- D. 2 Cu: 1 NO3-
12. Which species in each pair is a better reducing agent under standard state conditions?
1. Na or K 2. H2 or I2 A. Na, I2 B. K, I2 C. Na, H2 D. K, H2
13. Which of the following is not a good oxidizing agent?A. O2- B. O2 C. O2- D. H2O2
14. Which of the following is false?A. Reduction always takes place at the cathode. B. Good oxidizing agents are molecules or ions that are easily reduced. C. All electrochemical cells require a salt bridge. D. delta G for an electrolytic cell is always positive.
15. Identify the anode reaction and calculate Eo for the following reaction:
2 Al(s) + 3 Ni2+(aq) = 2 Al3+(aq) + 3 Ni(s) Anode Eo A. 3 Ni2+(aq) + 6 e = 3 Ni(s) -1.91 V
B. 2 Al3+(aq) + 6 e = 2 Al(s) +1.91 V
C. 3 Ni(s) = 3 Ni2+(aq) + 6 e -1.41 V
D. 2 Al(s) = 2 Al3+(aq) + 6 e +1.41 V
16. What is the correct value of n that should be used in the Nernst equation for the following reaction?
3 Fe2+(aq) + 2 Al(s) = 3 Fe(s) + 2 Al3+(aq) A. 1 B. 2 C. 3 D. 6
17. Calculate E and Eo for the reaction
Co(s) + Fe2+(aq) = Co2+(aq) + Fe(s) if [Co2+] = 0.15 M and [Fe2+] = 0.68 M at 25oC.
Eo E
A. -0.16 V 0.18 V B. -0.16 V 0.14 V C. 0.16 V 0.18 V D. 0.16 V 0.14 V
18. Which of the following is correct?Eo delta G Kc A. < 0 > 0 > 1 B. > 0 > 0 < 1 C. < 0 > 0 < 1 D. < 0 < 0 < 1
19. Calculate the equilibrium constant for the following reaction at 25oC.
Br2(l) + 2 I-(aq) = 2 Br-(aq) + I2(s) A. 2.1 x 10-24 B. 1.9 x 1018 C. 6.2 x 108 D. 5.6 x 10-9
20. A current of 10.0 amperes is passed through molten magnesium chloride, MgCl2(l), for 3.00 h. How many grams of magnesium metal could be produced by this electrolysis?A. 0.560 g B. 4.53 g C. 13.6 g D. 27.2 g
21. In which of the following does the italicized metal have the least protection against corrosion of the metal?A. An iron pipe connected to a piece of zinc. B. Stainless steel (iron alloyed with chromium and nickel). C. An aluminum soda can. D. An iron beam covered with paint.
22. Which of the following is false in regard to the transition metals?A. Many of the elements, upon ionizing, lose d electrons first. B. Most of their compounds are colored. C. Many of their compounds are paramagnetic. D. Most of the metals exhibit multiple oxidation states.
23. Which of the following metals has never been mined in its uncombined form (i.e., as a metal rather than a compound)?A. Ba B. Ag C. Pt D. Cu
24. Which of the following oxides cannot be reduced with CO(g)?A. HgO B. Al2O3 C. Fe2O3 D. SnO
25. Which of the following is a false statement?A. Zone refining is a method used for metal purification. B. Roasting converts metal oxides to metal sulfides. C. Iron oxides are reduced in the blast furnace. D. Flotation is a method used to concentrate ore.