Chemistry 2 Exam 2 Chapter 13

14) What are the units of k in the following rate law? Rate = k[X][Y] A) M/s B) Ms C) 1/Ms D) M^2/s E) s/M^2

C

59) Biological catalysts that increase the rates of biochemical reactions are known as ________. A) substrates B) inhibitors C) enzymes D) binders E) trumanettes

C

1) Given the following balanced equation, determine the rate of reaction with respect to [SO2]. 2 SO2(g) + O2(g) → 2 SO3(g) A) Rate = - B) Rate = + C) Rate = - D) Rate = + E) It is not possible to determine without more information.

A

11) What are the units of k in a zero order reaction? A) B) M C) M-1s-1 D) E)

A

15) What is the overall order of the following reaction, given the rate law? 2 X + 3 Y → 2 Z Rate = k[X]1[Y]2 A) 3rd order B) 5th order C) 2nd order D) 1st order E) 0th order

A

18) Given the following rate law, how does the rate of reaction change if the concentration of X is doubled? Rate = k [X][Y]2 A) The rate of reaction will increase by a factor of 2. B) The rate of reaction will increase by a factor of 3. C) The rate of reaction will increase by a factor of 5. D) The rate of reaction will decrease by a factor of 2. E) The rate of reaction will remain unchanged.

A

19) Determine the rate law and the value of k for the following reaction using the data provided. CO(g) + Cl2(g) → COCl2(g) [CO]i (M)[Cl2]i (M) al Rate (M-1s-1) 0.25 0.40 0.696 0.25 0.80 1.97 0.50 0.80 3.94 A) Rate = 11 M-3/2s-1 [CO][Cl2]3/2 B) Rate = 36 M-1.8s-1 [CO][Cl2]2.8 C) Rate = 17 M-2s-1 [CO][Cl2]2 D) Rate = 4.4 M-1/2s-1 [CO][Cl2]1/2 E) Rate = 18 M-3/2s-1 [CO]2[Cl2]1/2

A

19) Given the following rate law, how does the rate of reaction change if the concentration of Y is doubled? Rate = k [X][Y] A) The rate of reaction will increase by a factor of 2. B) The rate of reaction will increase by a factor of 4. C) The rate of reaction willdecrease by a factor of 3. D) The rate of reaction will decrease by a factor of 2. E) The rate of reaction will remain unchanged.

A

22) The decomposition of dinitrogen pentoxide is described by the chemical equation 2 N2O5(g) → 4 NO2(g) + O2(g) If the rate of appearance of NO2 is equal to 0.560 mol/min at a particular moment, what is the rate of appearance of O2 at that moment? A) 0.140 mol/min B) 0.280 mol/min C) 1.12 mol/min D) 2.24 mol/min

A

23) Carbon-14 has a half-life of 5720 years and this is a first order reaction. If a piece of wood has converted 75% of the carbon-14, then how old is it? A) 11440 years B) 2375 years C) 4750 years D) 4290 years E) 1430 years

A

25) Which of the following represents the integrated rate law for a first-order reaction? A) = - kt B) - = kt C) [A]t - [A]o = - kt D) k = Ae(-Ea/RT) E) = () + lnA

A

29) Which of the following represents the equation for a second-order half-life? A) t 1/2 = B) t 1/2 = C) t 1/2 = D) t 1/2 = E) t 1/2 =

A

32) How many half-lives are required for the concentration of reactant to decrease to 12.5% of its original value? A) 3 B) 2 C) 2.5 D) 2.75 E) 8

A

33) How many half-lives are required for the concentration of reactant to decrease to 1.56% of its original value? A) 6 B) 4 C) 24 D) 6.5 E) 7.5

A

35) The half life for the decay of radium is 1620 years. What is the rate constant for this first-order process? A) 4.28 × 10-4 yr-1 B) 1.12 × 10-4 yr-1 C) 2.33 × 10-4 yr-1 D) 8.91 × 10-4 yr-1 E) 6.17 × 10-4 yr-1

A

37) The first-order decomposition of N2O at 1000 K has a rate constant of 0.76 s-1. If the initial concentration of N2O is 10.9 M, what is the concentration of N2O after 9.6 s? A) 7.4 × 10-3 M B) 1.0 × 10-3 M C) 1.4 × 10-3 M D) 3.6 × 10-3 M E) 8.7 × 10-3 M

A

40) The combustion of ethylene proceeds by the reaction C2H4(g) + 3O2 (g) → 2CO2 (g) + 2H2O(g) When the rate of disappearance of O2 is 0.28 M s-1, the rate of appearance of CO2 is ________ M s-1. A) 0.19 B) 0.093 C) 0.84 D) 0.42 E) 0.56

A

46) Identify the rate-determining step. A) the slowest step B) the faster step C) the fast step D) always the last step E) always the second step

A

47) The first-order rearrangement of CH3NC is measured to have a rate constant of 3.61 x 10-15 s-1 at 298 K and a rate constant of 8.66 × 10-7 s-1 at 425 K. Determine the activation energy for this reaction. A) 160. kJ/mol B) 240. kJ/mol C) 417 kJ/mol D) 127 kJ/mol E) 338 kJ/mol

A

51) The isomerization reaction, CH3NC → CH3CN, is first order and the rate constant is equal to 0.46 s-1 at 600 K. What is the concentration of CH3NC after 0.20 minutes if the initial concentration is 0.30 M? A) 1.2 × 10-3 M B) 2.7 × 10-3 M C) 1.2 × 10-1 M D) 2.7 × 10-1 M

A

52) If the activation energy for a given compound is found to be 103 kJ/mol, with a frequency factor of 4.0 × 1013 s-1, what is the rate constant for this reaction at 398 K? A) 1.2 s-1 B) 8.2 s-1 C) 3.9 × 1010 s-1 D) 1.7 × 1010 s-1 E) 2.5 × 107 s-1

A

57) In the hydrogenation of double bonds, a catalyst is needed. In the first step, the reactants must come into contact with a metal surface. This step is known as ________. A) adsorption B) diffusion C) reaction D) desorption E) none of the above

A

6) Write a balanced reaction for which the following rate relationships are true. Rate = - = = A) 2 N2O5 → 4 NO2 + O2 B) 4 NO2 + O2 → 2 N2O5 C) 2 N2O5 → NO2 + 4 O2 D) NO2 + O2 → N2O5 E) N2O5 → NO2 + O2

A

64) A particular first-order reaction has a rate constant of 1.35 × 102 s-1 at 25.0°C. What is the magnitude of k at 95.0°C if Ea = 55.5 kJ/mol? A) 9.56 × 103 s-1 B) 2.85 × 104 s-1 C) 576 s-1 D) 4.33 × 1087 s-1 E) 1.36 × 102 s-1

A

66) Which rate law is termolecular? A) rate = k[A][B]2 B) rate = k [A][B]3 C) rate = k [A]5 D) rate = k [A][B][C][D] E) rate = k [A]2

A

68) Given the following proposed mechanism, predict the rate law for the overall reaction. 2NO2 + Cl2 → 2NO2Cl (overall reaction) Mechanism NO2 + Cl2 → NO2Cl + Cl slow NO2 + Cl → NO2Cl fast A) Rate = k[NO2][Cl2] B) Rate = k[NO2]2[Cl2]2 C) Rate = k[NO2][Cl] D) Rate = k[NO2Cl][Cl]2 E) Rate = k[NO2Cl]2

A

9) Give the characteristic of a zero order reaction having only one reactant. A) The rate of the reaction is not proportional to the concentration of the reactant. B) The rate of the reaction is proportional to the square of the concentration of the reactant. C) The rate of the reaction is proportional to the square root of the concentration of the reactant. D) The rate of the reaction is proportional to the natural logarithm of the concentration of the reactant. E) The rate of the reaction is directly proportional to the concentration of the reactant.

A

9) Given the following balanced equation, determine the rate of reaction with respect to [O2]. If the rate of formation of O2 is 7.78 x 10-1 M/s, what is the rate of the loss of O3? 2 O3(g) → 3 O2(g) A) 0.519 M/s B) 1.56 M/s C) 2.34 M/s D) 1.17 M/s E) 7.78 M/s

A

10) Give the characteristic of a second order reaction having only one reactant. A) The rate of the reaction is not proportional to the concentration of the reactant. B) The rate of the reaction is proportional to the square of the concentration of the reactant. C) The rate of the reaction is proportional to the square root of the concentration of the reactant. D) The rate of the reaction is proportional to the natural logarithm of the concentration of the reactant. E) The rate of the reaction is directly proportional to the concentration of the reactant.

B

11) What is the overall order of the following reaction, given the rate law? NO(g) + O3(g) → NO2(g) +O2(g) Rate = k[NO][O3] A) 1st order B) 2nd order C) 3rd order D) 1 order E) 0th order

B

12) What are the units of k in the following rate law? Rate = k[X][Y]2 A) 1/Ms^2 B) 1/M^2s C) M^2 s D) M^2/s E) 1/M^3s

B

17) Given the following rate law, how does the rate of reaction change if the concentration of Y is doubled? Rate = k [X][Y]2 A) The rate of reaction will increase by a factor of 2. B) The rate of reaction will increase by a factor of 4. C) The rate of reaction will increase by a factor of 5. D) The rate of reaction will decrease by a factor of 2. E) The rate of reaction will remain unchanged.

B

2) Given the following balanced equation, determine the rate of reaction with respect to [NOCl]. 2 NO(g) + Cl2(g) → 2 NOCl(g) A) Rate = - 1/2 [NOCl]/t B) Rate = + 1/2 [NOCl]/t C) Rate = - 1/2 [NO]/t D) Rate = - 2[NOCl]/t E) It is not possible to determine without more information.

B

20) Determine the rate law and the value of k for the following reaction using the data provided. S2O82⁻(aq) + 3 I⁻(aq) → 2 SO42⁻(g) + I3⁻(aq) [S2O82⁻]i (M) [I⁻]i (M) Initial Rate (M-1s-1) 0.30 0.42 4.54 0.44 0.42 6.65 0.44 0.21 3.33 A) Rate = 120 M-2s-1 [S2O82⁻]2[I⁻] B) Rate = 36 M-1s-1 [S2O82⁻][I⁻] C) Rate = 86 M-2s-1 [S2O82⁻][I⁻]2 D) Rate = 195 M-3s-1 [S2O82⁻]2[I⁻]2 E) Rate = 23 M-1/2s-1 [S2O82⁻][I⁻]1/2

B

24) Carbon-14 has a half-life of 5720 years and this is a first order reaction. If a piece of wood has converted 25% of the carbon-14, then how old is it? A) 11440 years B) 2375 years C) 4750 years D) 4290 years E) 1430 years

B

26) Which of the following represents the integrated rate law for a second-order reaction? A) = - kt B) - = kt C) [A]t - [A]o = - kt D) k = Ae(-Ea/RT) E) = () + lnA

B

28) Which of the following represents the equation for a first-order half-life? A) t 1/2 = B) t 1/2 = C) t 1/2 = D) t 1/2 = E) t 1/2 =

B

3) Given the following balanced equation, determine the rate of reaction with respect to [SO3]. 2 SO2(g) + O2(g) → 2 SO3(g) A) Rate = - B) Rate = + C) Rate = - D) Rate = - E) It is not possible to determine without more information.

B

32) Which of the following statements is FALSE? A) The half life of a zero order reaction is dependent on concentration. B) The half life of a second order reaction is not dependent on concentration. C) The rate of second order reactions is dependent on concentration. D) The rate of a first order reaction is dependent on concentraion. E) None of the statements are FALSE.

B

33) The rate constant for the first-order decomposition of N2O is 3.40 s-1. What is the half-life of the decomposition? A) 0.491 s B) 0.204 s C) 0.236 s D) 0.424 s E) 0.294 s

B

38) The rate of disappearance of HBr in the gas phase reaction 2HBr(g) → H2(g) + Br2(g) is 0.301 M at 150°C. The rate of appearance of Br2 is ________ M s-1. A) 1.66 B) 0.151 C) 0.0906 D) 0.602 E) 0.549

B

39) The rate of disappearance of HBr in the gas phase reaction 2HBr(g) → H2(g) + Br2(g) is 0.130 M s-1 at 150°C. The rate of reaction is ________ M s-1. A) 3.85 B) 0.0650 C) 0.0169 D) 0.260 E) 0.0860

B

41) The combustion of ethylene proceeds by the reaction C2H4(g) + 3O2(g) → 2CO2 (g) + 2H2O(g) When the rate of disappearance of O2 is 0.23 M s-1, the rate of disappearance of C2H4 is ________ M s-1. A) 0.15 B) 0.077 C) 0.69 D) 0.35 E) 0.46

B

43) The first-order decomposition of N2O5 at 328 K has a rate constant of 1.70 × 10-3 s-1. If the initial concentration of N2O5 is 2.88 M, what is the concentration of N2O5 after 12.5 minutes? A) 0.124 M B) 0.805 M C) 2.82 M D) 0.355 M E) 0.174 M

B

48) A reaction is followed and found to have a rate constant of 3.36 × 104 M-1s-1 at 344 K and a rate constant of 7.69 M-1s-1 at 219 K. Determine the activation energy for this reaction. A) 23.8 kJ/mol B) 42.0 kJ/mol C) 11.5 kJ/mol D) 12.5 kJ/mol E) 58.2 kJ/mol

B

48) For a particular first-order reaction, it takes 24 minutes for the concentration of the reactant to decrease to 25% of its initial value. What is the value for rate constant (in s-1) for the reaction? A) 2.0 × 10-4 s-1 B) 9.6 × 10-4 s-1 C) 1.2 × 10-2 s-1 D) 5.8 × 10-2 s-1

B

5) Given the following balanced equation, determine the rate of reaction with respect to [N2]. N2(g) + 3 H2(g) → 2 NH3(g) A) Rate = + [N2]/t B) Rate = - [N2]/t C) Rate = + 1/2 [N2]/t D) Rate = - 1/2 [N2]/t E) It is not possible to determine without more information.

B

50) The first-order reaction, 2 N2O(g) → 2 N2(g) + O2(g), has a rate constant equal to 0.76 s-1 at 1000 K. How long will it take for the concentration of N2O to decrease to 12% of its initial concentration? A) 0.62 s B) 2.8 s C) 6.3 s D) 8.4 s

B

52) The following reaction is first order, C2H6 → 2 CH3. If the rate constant is equal to 5.5 × 10-4 s-1 at 1000 K, how long will it take for 0.35 mol of C2H6 in a 1.00 L container to decrease to 0.20 mol in the same container? A) 4.5 min B) 17 min C) 53 min D) 65 min

B

55) For the first-order reaction, 2 N2O(g) → 2 N2(g) + O2(g), what is the concentration of N2O after 3 half-lives if 0.25 mol of N2O is initially placed into a 1.00-L reaction vessel? A) 1.6 × 10-2 M B) 3.1 × 10-2 M C) 6.2 × 10-2 M D) 1.2 × 10-1 M

B

56) Identify an heterogeneous catalyst. A) CFCs with ozone B) Pd in H2 gas C) KI dissolved in H2O2 D) H2SO4 with concentrated HCl E) H3PO4 with an alcohol

B

59) Nitrogen dioxide decomposes at 300°C via a second-order process to produce nitrogen monoxide and oxygen according to the following chemical equation. 2 NO2(g) → 2 NO(g) + O2(g). A sample of NO2(g) is initially placed in a 2.50-L reaction vessel at 300°C. If the half-life and the rate constant at 300°C are 11 seconds and 0.54 M-1 s-1, respectively, how many moles of NO2 were in the original sample? A) 0.17 mol B) 0.42 mol C) 5.9 mol D) 15 mol

B

60) Hydrogen iodide decomposes at 800 K via a second-order process to produce hydrogen and iodine according to the following chemical equation. 2HI(g) → H2(g) + I2(g) At 800 K it takes 142 seconds for the initial concentration of HI to decrease from 6.75 × 10-2 M to 3.50 × 10-2 M. What is the rate constant for the reaction at this temperature? A) 5.12 × 10-4 M-1s-1 B) 9.69 × 10-2 M-1s-1 C) 10.3 M-1s-1 D) 1.95 × 103 M-1s-1

B

61) Which of the following reactions would you predict to have the smallest orientation factor? A) X2 + Y2 → 2 XY B) NOCl2 + NO → 2 NOCl C) N2 + O2 → 2 NO D) N + O2 → NO2 E) All of these reactions should have nearly identical orientation factors.

B

63) The aquation of tris(1,10-phenanthroline)iron(II) in acid solution takes place according to the equation: Fe(phen)32+ + 3 H3O+ + 3 H2O → Fe(H2O)62+ + 3 phenH+. If the activation energy, Ea, is 126 kJ/mol and the rate constant at 30°C is 9.8 × 10-3 min-1, what is the rate constant at 35°C? A) 4.4 × 10-3 min-1 B) 2.2 × 10-2 min-1 C) 4.5 × 101 min-1 D) 2.3 × 102 min-1

B

65) A particular first-order reaction has a rate constant of 1.35 × 102 s-1 at 25.0°C. What is the magnitude of k at 75.0°C if Ea = 85.6 kJ/mol? A) 3.47 × 104 s-1 B) 1.92 × 104 s-1 C) 670 s-1 D) 3.85 × 106 s-1 E) 1.36 × 102 s-1

B

67) Which rate law is bimolecular? A) rate = k[A][B]3 B) rate = k [A][B] C) rate = k [A]3 D) rate = k [A][B][C][D] E) rate = k [A]2[B]2

B

7) Write a balanced reaction for which the following rate relationships are true. Rate = = = - A) N2 + O2 → N2O B) 2 N2O → 2 N2 + O2 C) N2O → N2 + 2 O2 D) N2O → N2 + O2 E) 2 N2 + O2 → 2 N2O

B

10) What is the overall order of the following reaction, given the rate law? X + 2 Y → 4 Z Rate = k[X][Y] A) 3rd order B) 5th order C) 2nd order D) 1st order E) 6th order

C

13) What are the units of k in a second order reaction? A) B) M C) M-1s-1 D) E)

C

14) The decomposition of dinitrogen pentoxide is described by the chemical equation 2 N2O5(g) → 4 NO2(g) + O2(g) If the rate of disappearance of N2O5 is equal to 1.60 mol/min at a particular moment, what is the rate of appearance of NO2 at that moment? A) 0.800 mol/min B) 1.60 mol/min C) 3.20 mol/min D) 6.40 mol/min

C

16) What is the overall order of the following reaction, given the rate law? 2NO(g) + H2(g) → N2(g) + 2H2O(g) Rate = k[NO]2[H2] A) 1st order B) 1st order C) 3rd order D) 4th order E) 5th order

C

18) What are the units of k in the following rate law? Rate = k[X]2 A) Ms-1 B) Ms C) M-1s-1 D) M-2s-1 E) M2s-1

C

2) Given the following balanced equation, determine the rate of reaction with respect to [O2]. 2 SO2(g) + O2(g) → 2 SO3(g) A) Rate = - B) Rate = + C) Rate = - D) Rate = + E) It is not possible to determine without more information.

C

20) Given the following rate law, how does the rate of reaction change if the concentration of Y is doubled? Rate = k [X]2[Y]3 A) The rate of reaction will increase by a factor of 5. B) The rate of reaction will increase by a factor of 2. C) the rate of reaction will increase by a factor of 8. D) The rate of reaction will increase by a factor of 3. E) The rate of reaction will remain unchanged.

C

21) Determine the rate law and the value of k for the following reaction using the data provided. NO2(g) + O3(g) → NO3(g) + O2(g) [NO2]i (M) [O3]i (M) Initial Rate (M-1s-1) 0.10 0.33 1.42 0.10 0.66 2.84 0.25 0.66 7.10 A) Rate = 1360 M-2.5s-1[NO2]2.5[O3] B) Rate = 227 M-2.5s-1[NO2][O3]2.5 C) Rate = 43 M-1s-1[NO2][O3] D) Rate = 430 M-2s-1[NO2]2[O3] E) Rate = 130 M-2s-1[NO2][O3]2

C

23) The decomposition of dinitrogen pentoxide is described by the chemical equation 2 N2O5(g) → 4 NO2(g) + O2(g) If the rate of appearance of O2 is equal to 3.00 mol/min at a particular moment, what is the rate of disappearance of N2O5 at that moment? A) 0.750 mol/min B) 1.50 mol/min C) 6.00 mol/min D) 12.0 mol/min

C

24) For a reaction that follows the general rate law, Rate = k[A][B]2, what will happen to the rate of reaction if the concentration of A is increased by a factor of 5.00? The rate will A) decrease by a factor of 1/25.0. B) decrease by a factor of 1/5.00. C) increase by a factor of 5.00. D) increase by a factor of 25.0.

C

27) Which of the following represents the integrated rate law for a zeroth-order reaction? A) = - kt B) - = kt C) [A]t - [A]o = - kt D) k = Ae(-Ea/RT) E) = () + lnA

C

28) What data should be plotted to show that experimental concentration data fits a first-order reaction? A) 1/[reactant] vs. time B) [reactant] vs. time C) ln[reactant] vs. time D) ln(k) vs. 1/T E) ln(k) vs. Ea

C

30) Which of the following represents the equation for a zero-order half-life? A) t 1/2 = B) t 1/2 = C) t 1/2 = D) t 1/2 = E) t 1/2 =

C

34) The half-life for the second-order decomposition of HI is 15.4 s when the initial concentration of HI is 0.67 M. What is the rate constant for this reaction? A) 1.0 × 10-2 M-1s-1 B) 4.5 × 10-2 M-1s-1 C) 9.7 × 10-2 M-1s-1 D) 2.2 × 10-2 M-1s-1 E) 3.8 × 10-2 M-1s-1

C

37) The rate constant for a zero-order reaction is 0.54 M-1s-1. What is the half-life of this reaction if the initial concentration is 0.33 M? A) 0.089 s B) 1.8 s C) 0.31 s D) 5.6 s E) 1.3 s

C

38) The second-order decomposition of HI has a rate constant of 1.80 x 10-3 M-1s-1. How much HI remains after 27.3 s if the initial concentration of HI is 4.78 M? A) 4.55 M B) 0.258 M C) 3.87 M D) 2.20 M E) 2.39 M

C

4) Given the following balanced equation, determine the rate of reaction with respect to [NH3]. N2(g) + 3 H2(g) → 2 NH3(g) A) Rate = + 2[NH3]/t B) Rate = - 2[NH3]/t C) Rate = + 1/2 [NH3]/t D) Rate = - 1/2 [NH3]/t E) It is not possible to determine without more information.

C

4) Given the following balanced equation, determine the rate of reaction with respect to [O2]. 2 O3(g) → 3 O2(g) A) Rate = + B) Rate = - C) Rate = + D) Rate = - E) It is not possible to determine without more information.

C

44) The isomerization of methylisonitrile to acetonitrile CH3NC(g) → CH3CN(g) is first order in CH3NC. The half life of the reaction is 5.20 × 101 s at 545 K. The rate constant when the initial [CH3NC] is 0.030 M is ________ s-1. A) 75.1 B) 0.641 C) 0.0133 D) 1.56 E) 2.84 × 104

C

45) For a reaction, what generally happens if the temperature is increased? A) a decrease in k occurs, which results in a faster rate B) a decrease in k occurs, which results in a slower rate C) an increase in k occurs, which results in a faster rate D) an increase in k occurs, which results in a slower rate E) there is no change with k or the rate

C

45) The decomposition of N2O5 in solution in carbon tetrachloride proceeds via the reaction 2N2O5 (soln) → 4NO2 (soln) + O2 (soln) The reaction is first order and has a rate constant of 4.82 × 10-3 s-1 at 64°C. If the reaction is initiated with 0.058 mol in a 1.00-L vessel, how many moles remain after 151 s? A) 0.055 M B) 0.060 M C) 0.028 M D) 12 M E) 2.0 × 103 M

C

46) SO2Cl2 decomposes in the gas phase by the reaction SO2Cl2(g) → SO2(g) + Cl2(g) The reaction is first order in SO2Cl2 and the rate constant is 3.0 × 10-6 s-1 at 600 K. A vessel is charged with 2.4 atm of SO2Cl2 at 600 K. The partial pressure of SO2Cl2 at 3.0 × 105 s is ________ atm. A) 0.76 B) 2.2 C) 0.98 D) 0.29 E) 1.4 × 105

C

47) The reaction that occurs in a Breathalyzer, a device used to determine the alcohol level in a person's bloodstream, is given below. If the rate of appearance of Cr2(SO4)3 is 1.64 mol/min at a particular moment, what is the rate of disappearance of C2H6O at that moment? 2 K2Cr2O7 + 8 H2SO4 + 3 C2H6O → 2 Cr2(SO4)3 + 2 K2SO4 + 11 H2O A) 0.547 mol/min B) 1.09 mol/min C) 2.46 mol/min D) 4.92 mol/min

C

49) A reaction is found to have an activation energy of 108 kJ/mol. If the rate constant for this reaction is 4.60 × 10-6 s-1 at 275 K, what is the rate constant at 366 K? A) 12 s-1 B) 1.7 s-1 C) 0.58 s-1 D) 5.4 × 10-5 s-1 E) 1.9 × 10-4 s-1

C

53) The rate constant, k, for a first-order reaction is equal to 4.2 × 10-4 s-1. What is the half-life for the reaction? A) 2.9 × 10-4 s B) 1.2 × 103 s C) 1.7 × 103 s D) 2.4 × 103 s

C

54) Which of the following statements is TRUE? A) The rate constant does not depend on the activation energy for a reaction where the products are lower in energy than the reactants. B) A catalyst raises the activation energy of a reaction. C) Rate constants are temperature dependent. D) The addition of a homogeneous catalyst does not change the activation energy of a given reaction. E) None of the above are true.

C

56) Carbon-14, which is present in all living tissue, radioactively decays via a first-order process. A one-gram sample of wood taken from a living tree gives a rate for carbon-14 decay of 13.6 counts per minute. If the half-life for carbon-14 is 5720 years, how old is a wood sample that gives a rate for carbon-14 decay of 11.9 counts per minute? A) 5.3 × 102 yr B) 7.6 × 102 yr C) 1.1 × 103 yr D) 9.4 × 103 yr

C

58) The second-order reaction 2 Mn(CO)5 → Mn2(CO)10, has a rate constant equal to 3.0 × 109 M-1 s-1 at 25°C. If the initial concentration of Mn(CO)5 is 2.0 × 10-5 M, how long will it take for 90.% of the reactant to disappear? A) 6.7 × 10-16 s B) 7.4 × 10-15 s C) 1.5 × 10-4 s D) 6.0 × 103 s

C

) Given the following balanced equation, determine the rate of reaction with respect to [Cl2]. If the rate of Cl2 loss is 4.24 × 10-2 M/s, what is the rate of formation of NO? 2 NO(g) + Cl2(g) → 2 NOCl(g) A) 4.24 × 10-2 M/s B) 2.12 × 10-2 M/s C) 1.06 × 10-1 M/s D) 8.48 × 10-2 M/s E) 1.61 × 10-2 M/s

D

15) What are the units of k in the following rate law? Rate = k[X] A) M/s B) Ms C) 1/Ms D) 1/s E) s/M

D

16) What are the units of k in the following rate law? Rate = k[X]0[Y]0 A) M/s B) Ms C) M-1s-1 D) 1/s E) s/M^2

D

17) What are the units of k in the following rate law? Rate = k[X][Y]1/2 A) M/s B) M-1s-1 C) M1/2s-1 D) M-1/2s-1 E) M-1s-1/2

D

22) Determine the rate law and the value of k for the following reaction using the data provided. 2 NO(g) + O2(g) → 2 NO2(g) [NO]i (M) [O2]i (M) Initial Rate (M-1s-1) 0.030 0.0055 8.55 x 10-3 0.030 0.0110 1.71 x 10-2 0.060 0.0055 3.42 x 10-2 A) Rate = 57 M-1s-1[NO][O2] B) Rate = 3.8 M-1/2s-1[NO][O2]1/2 C) Rate = 3.1 × 105 M-3s-1[NO]2[O2]2 D) Rate = 1.7 × 103 M-2s-1[NO]2[O2] E) Rate = 9.4 × 103 M-2s-1[NO][O2]2

D

25) For a reaction that follows the general rate law, Rate = k[A][B]2, what will happen to the rate of reaction if the concentration of B is increased by a factor of 3.00? The rate will A) decrease by a factor of 1/9.00. B) decrease by a factor of 1/3.00. C) increase by a factor of 3.00. D) increase by a factor of 9.00.

D

26) What is the overall reaction order for the reaction that has the rate law: Rate = k[O2] [NO ]2? A) zero order B) first order C) second order D) third order

D

27) Given the following rate law, how does the rate of reaction change if the concentration of X is doubled? Rate = k [X]2[Y]3 A) The rate of reaction will increase by a factor of 9. B) The rate of reaction will increase by a factor of 5. C) the rate of reaction will increase by a factor of 6. D) The rate of reaction will increase by a factor of 4. E) The rate of reaction will remain unchanged.

D

29) What data should be plotted to show that experimental concentration data fits a second-order reaction? A) ln[reactant] vs. time B) [reactant] vs. time C) ln(k) vs. 1/T D) 1/[reactant] vs. time E) ln(k) vs. Ea

D

3) Given the following balanced equation, determine the rate of reaction with respect to [H2]. N2(g) + 3 H2(g) → 2 NH3(g) A) Rate = + 3[H2]/t B) Rate = - 3[H2]/t C) Rate = + 1/3 [H2]/t D) Rate = - 1/3 [H2]/t E) It is not possible to determine without more information.

D

31) Which of the following statements is FALSE? A) The average rate of a reaction decreases during a reaction. B) It is not possible to determine the rate of a reaction from its balanced equation. C) The rate of zero order reactions are not dependent on concentration. D) The half life of a first order reaction is dependent on the initial concentration of reactant. E) None of the statements are FALSE.

D

34) If the concentration of a reactant is 6.25%, how many half-lives has it gone through? A) 7 B) 10 C) 3 D) 4 E) 5

D

35) The rate constant for a second-order reaction is 0.54 M-1s-1. What is the half-life of this reaction if the initial concentration is 0.33 M? A) 0.089 s B) 1.8 s C) 0.31 s D) 5.6 s E) 1.3 s

D

36) The first-order decomposition of cyclopropane has a rate constant of 6.7 x 10-4 s-1. If the initial concentration of cyclopropane is 1.33 M, what is the concentration of cyclopropane after 644 s? A) 0.43 M B) 0.15 M C) 0.94 M D) 0.86 M E) 0.67 M

D

39) Derive an expression for a "1/3-life" for a first-order reaction. A) B) C) D) E)

D

42) The isomerization of methylisonitrile to acetonitrile CH3NC(g) → CH3CN(g) is first order in CH3NC. The rate constant for the reaction is 9.45 × 10-5 s-1 at 478 K. The half-life of the reaction when the initial [CH3NC] is 0.030 M is ________ s. A) 1.06 × 104 B) 5.29 × 103 C) 3.53E × 105 D) 7.33 × 103 E) 1.36 × 10-4

D

43) The elementary reaction 2NO2 (g) → 2NO(g) + O2 (g) is second order in NO2 and the rate constant at 501 K is 7.93 × 10-3 M-1 s-1. The reaction half-life at this temperature when [NO2]0 = 0.45 M is ________ s. A) 3.6 × 10-3 B) 0.011 C) 126 D) 87 E) 280

D

44) The second-order decomposition of NO2 has a rate constant of 0.255 M-1s-1. How much NO2 decomposes in 4.00 s if the initial concentration of NO2 (1.00 L volume) is 1.33 M? A) 1.8 mol B) 0.85 mol C) 0.48 mol D) 0.77 mol E) 0.56 mol

D

49) The first-order reaction, SO2Cl2 → SO2 + Cl2, has a rate constant equal to 2.20 × 10-5 s-1 at 593 K. What percentage of the initial amount of SO2Cl2 will remain after 6.00 hours? A) 1.00% B) 37.8% C) 40.2% D) 62.2%

D

5) Given the following balanced equation, determine the rate of reaction with respect to [H2]. N2(g) + 3 H2(g) → 2 NH3(g) A) Rate = + B) Rate = - C) Rate = + D) Rate = - E) It is not possible to determine without more information.

D

50) A reaction is found to have an activation energy of 38.0 kJ/mol. If the rate constant for this reaction is 1.60 × 102 M-1s-1 at 249 K, what is the rate constant at 436 K? A) 2.38 × 105 M-1s-1 B) 1.26 × 103 M-1s-1 C) 7.94 × 104 M-1s-1 D) 4.20 × 105 M-1s-1 E) 3.80 × 104 M-1s-1

D

54) The first-order reaction, SO2Cl2 → SO2 + Cl2, has a half-life of 8.75 hours at 593 K. How long will it take for the concentration of SO2Cl2 to fall to 16.5% of its initial value? A) 0.143 hr B) 2.28 hr C) 6.99 hr D) 22.7 hr

D

55) Identify an homogeneous catalyst. A) SO2 over vanadium (V) oxide B) Pd in H2 gas C) Pt with methane D) H2SO4 with concentrated HCl E) N2 and H2 catalyzed by Fe

D

57) In aqueous solution, hypobromite ion, BrO-, reacts to produce bromate ion, BrO3-, and bromide ion, Br-, according to the following chemical equation. 3 BrO-(aq) → BrO3-(aq) + 2 Br-(aq) A plot of 1/[BrO-] vs. time is linear and the slope is equal to 0.056 M-1s-1. If the initial concentration of BrO- is 0.80 M, how long will it take one-half of the BrO- ion to react? A) 4.5 × 10-2 s B) 7.1 s C) 12 s D) 22 s

D

58) In the hydrogenation of double bonds, a catalyst is needed. In the last step, the reactants must escape from the surface into the gas phase. This step is known as ________. A) adsorption B) diffusion C) reaction D) desorption E) none of the above

D

6) Given the following balanced equation, determine the rate of reaction with respect to [Cl2]. If the rate of Cl2 loss is 4.24 × 10-2 M/s, what is the rate of formation of NOCl? 2 NO(g) + Cl2(g) → 2 NOCl(g) A) 4.24 × 10-2 M/s B) 2.12 × 10-2 M/s C) 1.06 × 10-1 M/s D) 8.48 × 10-2 M/s E) 1.61 × 10-2 M/s

D

62) Which of the following reactions would you predict to have the largest orientation factor? A) NOCl(g) + NOCl(g) → 2NO(g) + Cl2(g) B) Br2(g) + H2C=CH2(g) → H2BrC-CBrH2(g) C) NH3(g) + BCl3(g) → H3N-BCl3(g) D) H(g) + F(g) → HF(g) E) All of these reactions should have nearly identical orientation factors.

D

1) Identify the methods used to monitor a reaction as it occurs in the reaction flask. A) polarimeter B) spectrometer C) pressure measurement D) none of the above E) all of the above

E

12) What are the units of k in a first order reaction? A) B) M C) M-1s-1 D) E)

E

13) What are the units of k in the following rate law? Rate = k[X]2[Y]2 A) 1/Ms^2 B) 1/M^2s C) M2 s D) M^2/s E) 1/M^3s

E

21) Determine the rate law and the value of k for the following reaction using the data provided. 2 N2O5(g) → 4 NO2(g) + O2(g) [ N2O5]i (M) Initial Rate (M-1s-1) 0.093 4.84 x 10-4 0.084 4.37 x 10-4 0.224 1.16 x 10-3 A) Rate = 5.6 × 10-2 M-1s-1[N2O5]2 B) Rate = 6.0 × 10-1 M-2s-1[N2O5]3 C) Rate = 1.6 × 10-3 M1/2s-1[N2O5]1/2 D) Rate = 1.7 × 10-2 M-1/2s-1[N2O5]3/2 E) Rate = 5.2 × 10⁻3 s-1[N2O5]

E

30) What data should be plotted to show that experimental concentration data fits a zeroth-order reaction? A) ln[reactant] vs. time B) 1/[reactant] vs. time C) ln(k) vs. 1/T D) ln(k) vs. Ea E) [reactant] vs. time

E

31) How many half-lives are required for the concentration of reactant to decrease to 25% of its original value? A) 1 B) 4 C) 1.5 D) 3.5 E) 2

E

36) The rate constant for a first-order reaction is 0.54 M-1s-1. What is the half-life of this reaction if the initial concentration is 0.33 M? A) 0.089 s B) 1.8 s C) 0.31 s D) 5.6 s E) 1.3 s

E

40) Derive an expression for a "1/4-life" for a first-order reaction. A) B) C) D) E)

E

41) The first-order decay of radon has a half-life of 3.823 days. How many grams of radon remain after 7.22 days if the sample initially weighs 250.0 grams? A) 4.21 g B) 183 g C) 54.8 g D) 76.3 g E) 67.5 g

E

42) The first-order decay of radon has a half-life of 3.823 days. How many grams of radon decomposes after 5.55 days if the sample initially weighs 100.0 grams? A) 83.4 g B) 16.6 g C) 50.0 g D) 36.6 g E) 63.4 g

E

51) If the activation energy for a given compound is found to be 42.0 kJ/mol, with a frequency factor of 8.0 × 1010 s-1, what is the rate constant for this reaction at 298 K? A) 2.9 × 10-4 s-1 B) 7.4 × 10-4 s-1 C) 1.4 × 109 s-1 D) 4.6 × 10 5 s-1 E) 3.5 × 103 s-1

E

53) Given the following proposed mechanism, predict the rate law for the overall reaction. A2 + 2B → 2AB (overall reaction) Mechanism A2 ⇌ 2A fast A + B → AB slow A) Rate = k[A][B] B) Rate = k[A2][B] C) Rate = k[A2][B]1/2 D) Rate = k[A2] E) Rate = k [A2]1/2[B]

E

8) Give the characteristic of a first order reaction having only one reactant. A) The rate of the reaction is not proportional to the concentration of the reactant. B) The rate of the reaction is proportional to the square of the concentration of the reactant. C) The rate of the reaction is proportional to the square root of the concentration of the reactant. D) The rate of the reaction is proportional to the natural logarithm of the concentration of the reactant. E) The rate of the reaction is directly proportional to the concentration of the reactant.

E

8) Given the following balanced equation, determine the rate of reaction with respect to [O2]. If the rate of O2 loss is 2.64 x 10-3 M/s, what is the rate of formation of SO3? 2 SO2(g) + O2(g) → 2 SO3(g) A) 2.64 × 10-3 M/s B) 1.19 × 10-3 M/s C) 1.32 × 10-3 M/s D) 6.60 × 10-2 M/s E) 5.28 × 10-3 M/s

E

Match the following. A) activation energy B) half-life C) frequency factor D) reaction order E) rate constant 1) k 2) n, in Rate = k[A]n 3) t1/2 4) Ea 5) A

EDBAC