Question 1

What is the activation energy for a reaction that has a rate constant of 5.68 × 10-8 s-1 at 298 K and 1.73 × 10-5 s-1 at 348 K?

Accepted Answer

A)  66.2 kJ mol-1 
B)  98.6 kJ mol-1 
C)  19.4 kJ mol-1 
D)  41.4 kJ mol-1 
E)  70.0 kJ mol-1 
A)  66.2 kJ mol-1 
B)  98.6 kJ mol-1 
C)  19.4 kJ mol-1 
D)  41.4 kJ mol-1 
E)  70.0 kJ mol-1

Question 2

Which of the following statements is TRUE?

Accepted Answer

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 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 is true.

Question 3

The first-order decomposition of cyclopropane has a rate constant of 6.7 × 10-4 s-1. If the initial concentration of cyclopropane is 1.33 mol L-1, what is the concentration of cyclopropane after 644 s?

Accepted Answer

A)  0.43 mol L-1 
B)  0.15 mol L-1 
C)  0.94 mol L-1 
D)  0.86 mol L-1 
E)  0.67 mol L-1 
A)  0.43 mol L-1 
B)  0.15 mol L-1 
C)  0.94 mol L-1 
D)  0.86 mol L-1 
E)  0.67 mol L-1

Question 4

Without performing complex calculations, determine the order of a reaction that has the following initial rates for the specified starting concentration:

Accepted Answer

A)  zero order 
B)  first order 
C)  second order 
D)  third order 
E)  impossible to determine 
A)  zero order 
B)  first order 
C)  second order 
D)  third order 
E)  impossible to determine

Question 5

A reaction with an activation energy of 71.6 kJ mol-1 has a rate constant of 8.14 L mol-1 s-1 at 350 K. At what temperature will the rate constant be one-half?

Accepted Answer

A)  175 K 
B)  340 K 
C)  385 K 
D)  331 K 
E)  279 K 
A)  175 K 
B)  340 K 
C)  385 K 
D)  331 K 
E)  279 K

Question 6

Calculate the activation energy, Ea, for a reaction with a frequency factor, A, of 6.10 × 1014 s-1 and a rate constant of 13.0 s-1 at 320 K.

Accepted Answer

A)  62.8 kJ mol-1 
B)  83.8 kJ mol-1 
C)  41.3 kJ mol-1 
D)  97.9 kJ mol-1 
E)  106 kJ mol-1 
A)  62.8 kJ mol-1 
B)  83.8 kJ mol-1 
C)  41.3 kJ mol-1 
D)  97.9 kJ mol-1 
E)  106 kJ mol-1

Question 7

Which of the following reactions would you predict to have the largest orientation factor?

Accepted Answer

A)  NOF(g) + NOF(g) → 2NO(g) + F2(g) 
B)  Br2(g) + H2C=CH2(g) → H2BrC-CBrH2(g) 
C)  NH3(g) + BCl3(g) → H3N-BCl3(g) 
D)  H(g) + Cl(g) → HCl(g) 
E)  All of these reactions should have nearly identical orientation factors. 
A)  NOF(g) + NOF(g) → 2NO(g) + F2(g) 
B)  Br2(g) + H2C=CH2(g) → H2BrC-CBrH2(g) 
C)  NH3(g) + BCl3(g) → H3N-BCl3(g) 
D)  H(g) + Cl(g) → HCl(g) 
E)  All of these reactions should have nearly identical orientation factors.

Question 8

Identify a heterogeneous catalyst.

Accepted Answer

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

Question 9

What is a catalyst and what function does it serve?

Accepted Answer

A catalyst is a substance that is not us

Question 10

The half-life for the second-order decomposition of HI is 15.4 s when the initial concentration of HI is 0.67 mol L-1. What is the rate constant for this reaction?

Accepted Answer

A)  1.0 × 10-2 L mol-1 s-1 
B)  4.5 × 10-2 L mol-1 s-1 
C)  9.7 × 10-2 L mol-1 s-1 
D)  2.2 × 10-2 L mol-1 s-1 
E)  3.8 × 10-2 L mol-1 s-1 
A)  1.0 × 10-2 L mol-1 s-1 
B)  4.5 × 10-2 L mol-1 s-1 
C)  9.7 × 10-2 L mol-1 s-1 
D)  2.2 × 10-2 L mol-1 s-1 
E)  3.8 × 10-2 L mol-1 s-1

Question 11

Calculate the temperature if a reaction has a rate constant, k, of 841 s-1, a frequency factor, A, of 6.0 × 1012 s-1, and an activation energy, Ea, of 62 kJ mol-1.

Accepted Answer

A)  320 K 
B)  340 K 
C)  280 K 
D)  330 K 
E)  380 K 
A)  320 K 
B)  340 K 
C)  280 K 
D)  330 K 
E)  380 K

Question 12

Given the following balanced equation, determine the rate of reaction with respect to [SO3]. If the rate of SO2 loss is 1.19 × 10-3 mol L-1 s-1, what is the rate of formation of SO3? 2SO2(g) + O2(g) → 2SO3(g)

Accepted Answer

A)  3.56 × 10-3 mol L-1 s-1 
B)  1.19 × 10-3 mol L-1 s-1 
C)  1.78 × 10-3 mol L-1 s-1 
D)  1.42 × 10-2 mol L-1 s-1 
E)  7.12 × 10-3 mol L-1 s-1 
A)  3.56 × 10-3 mol L-1 s-1 
B)  1.19 × 10-3 mol L-1 s-1 
C)  1.78 × 10-3 mol L-1 s-1 
D)  1.42 × 10-2 mol L-1 s-1 
E)  7.12 × 10-3 mol L-1 s-1

Question 13

A catalyst is needed in the hydrogenation of double bonds. In the first step, the reactants must come into contact with a metal surface. This step is known as ________.

Accepted Answer

A)  adsorption 
B)  diffusion 
C)  reaction 
D)  desorption 
E)  none of the above 
A)  adsorption 
B)  diffusion 
C)  reaction 
D)  desorption 
E)  none of the above

Question 14

Determine the missing initial rate for the following   order reaction given the following information:

Accepted Answer

A)  0.48 mol L-1 s-1 
B)  0.38 mol L-1 s-1 
C)  0.91 mol L-1 s-1 
D)  1.3 mol L-1 s-1 
E)  0.84 mol L-1 s-1 
A)  0.48 mol L-1 s-1 
B)  0.38 mol L-1 s-1 
C)  0.91 mol L-1 s-1 
D)  1.3 mol L-1 s-1 
E)  0.84 mol L-1 s-1

Question 15

A reaction is found to have an activation energy of 108 kJ mol-1. 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?

Accepted Answer

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 
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

Question 16

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?

Accepted Answer

A)  The rate will decrease by a factor of 1/ 9.00. 
B)  The rate will decrease by a factor of 1/ 3.00. 
C)  The rate will increase by a factor of 3.00. 
D)  The rate will increase by a factor of 9.00. 
A)  The rate will decrease by a factor of 1/ 9.00. 
B)  The rate will decrease by a factor of 1/ 3.00. 
C)  The rate will increase by a factor of 3.00. 
D)  The rate will increase by a factor of 9.00.

Question 17

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

Accepted Answer

A)  Rate = k[NO2][Cl2] 
B)  Rate = k[NO2]2[Cl2] 
C)  Rate = k[NO2][Cl] 
D)  Rate = k[NO2Cl][Cl] 
E)  Rate = k[NO2Cl]2 
A)  Rate = k[NO2][Cl2] 
B)  Rate = k[NO2]2[Cl2] 
C)  Rate = k[NO2][Cl] 
D)  Rate = k[NO2Cl][Cl] 
E)  Rate = k[NO2Cl]2

Question 18

Match the following.
-k

Accepted Answer

A) reaction order 
B) frequency factor 
C) activation energy 
D) rate constant 
E) half-life 
A) reaction order 
B) frequency factor 
C) activation energy 
D) rate constant 
E) half-life

Question 19

A reaction with an activation energy of 84.6 kJ mol-1 has a rate constant of 0.00681 L mol-1 s-1 at 325 K. What is the rate constant at 375 K?

Accepted Answer

A)  9.11 × 10-3 L mol-1 s-1 
B)  5.25 L mol-1 s-1 
C)  0.443 L mol-1 s-1 
D)  0.0276 L mol-1 s-1 
E)  1.05 × 10-4 L mol-1 s-1 
A)  9.11 × 10-3 L mol-1 s-1 
B)  5.25 L mol-1 s-1 
C)  0.443 L mol-1 s-1 
D)  0.0276 L mol-1 s-1 
E)  1.05 × 10-4 L mol-1 s-1

Question 20

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?

Accepted Answer

A)  2.9 × 10-4 s 
B)  1.2 × 103 s 
C)  1.7 × 103 s 
D)  2.4 × 103 s 
A)  2.9 × 10-4 s 
B)  1.2 × 103 s 
C)  1.7 × 103 s 
D)  2.4 × 103 s

Exam 13: Chemical Kinetics

What is the activation energy for a reaction that has a rate constant of 5.68 × 10-8 s-1 at 298 K and 1.73 × 10-5 s-1 at 348 K?

Which of the following statements is TRUE?

The first-order decomposition of cyclopropane has a rate constant of 6.7 × 10-4 s-1. If the initial concentration of cyclopropane is 1.33 mol L-1, what is the concentration of cyclopropane after 644 s?

Without performing complex calculations, determine the order of a reaction that has the following initial rates for the specified starting concentration:

A reaction with an activation energy of 71.6 kJ mol-1 has a rate constant of 8.14 L mol-1 s-1 at 350 K. At what temperature will the rate constant be one-half?

Calculate the activation energy, Ea, for a reaction with a frequency factor, A, of 6.10 × 1014 s-1 and a rate constant of 13.0 s-1 at 320 K.

Which of the following reactions would you predict to have the largest orientation factor?

Identify a heterogeneous catalyst.

What is a catalyst and what function does it serve?

The half-life for the second-order decomposition of HI is 15.4 s when the initial concentration of HI is 0.67 mol L-1. What is the rate constant for this reaction?

Calculate the temperature if a reaction has a rate constant, k, of 841 s-1, a frequency factor, A, of 6.0 × 1012 s-1, and an activation energy, Ea, of 62 kJ mol-1.

Given the following balanced equation, determine the rate of reaction with respect to [SO3]. If the rate of SO2 loss is 1.19 × 10-3 mol L-1 s-1, what is the rate of formation of SO3? 2SO2(g) + O2(g) → 2SO3(g)

A catalyst is needed in the hydrogenation of double bonds. In the first step, the reactants must come into contact with a metal surface. This step is known as ________.

Determine the missing initial rate for the following order reaction given the following information:

A reaction is found to have an activation energy of 108 kJ mol-1. 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?

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?

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

Match the following. -k

A reaction with an activation energy of 84.6 kJ mol-1 has a rate constant of 0.00681 L mol-1 s-1 at 325 K. What is the rate constant at 375 K?

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?

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What is the activation energy for a reaction that has a rate constant of 5.68 × 10^-8 s^-1at 298 K and 1.73 × 10^-5 s^-1 at 348 K?

The first-order decomposition of cyclopropane has a rate constant of 6.7 × 10^-4 s^-1. If the initial concentration of cyclopropane is 1.33 mol L^-1, what is the concentration of cyclopropane after 644 s?

A reaction with an activation energy of 71.6 kJ mol^-1 has a rate constant of 8.14 L mol^-1 s^-1 at 350 K. At what temperature will the rate constant be one-half?

Calculate the activation energy, E_a, for a reaction with a frequency factor, A, of 6.10 × 10¹⁴ s^-1 and a rate constant of 13.0 s^-1 at 320 K.

The half-life for the second-order decomposition of HI is 15.4 s when the initial concentration of HI is 0.67 mol L^-1. What is the rate constant for this reaction?

Calculate the temperature if a reaction has a rate constant, k, of 841 s^-1, a frequency factor, A, of 6.0 × 10¹² s^-1, and an activation energy, E_a, of 62 kJ mol^-1.

Given the following balanced equation, determine the rate of reaction with respect to [SO₃]. If the rate of SO₂ loss is 1.19 × 10^-3 mol L^-1 s^-1, what is the rate of formation of SO₃? 2SO₂(g) + O₂(g) → 2SO₃(g)

A reaction is found to have an activation energy of 108 kJ mol^-1. 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?

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?

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 reaction with an activation energy of 84.6 kJ mol^-1 has a rate constant of 0.00681 L mol^-1 s^-1 at 325 K. What is the rate constant at 375 K?

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?