Question 1

The rate law for the reaction 3A  2B is rate = k[A] with a rate constant of 0.0447 hr-1. What is the half-life of the reaction?

Accepted Answer

A)   0.0224 hr
B)   0.0645 hr
C)   15.5 hr
D)   22.4 hr
E)   44.7 hrF) B) and E)
G) A) and B)

Question 2

The decomposition of hydrogen peroxide is a first-order process with a rate constant of 1.06 × 10-3 min-1. How long will it take for the concentration of H2O2 to drop from 0.0200 M to 0.0120 M?

Accepted Answer

A)   
B)   7.55 min
C)   481 min
D)   4550 min
E)   31,400 minF) A) and C)
G) C) and E)

Question 3

A rate constant obeys the Arrhenius equation, the factor A being 2.2 × 1013 s-1 and the activation energy being 150. kJ mol-1. What is the value of the rate constant at 227°C, in s-1?

Accepted Answer

A)   2.1 × 1013 s-1
B)   6.7 × 10-22 s-1
C)   1.5 × 1011 s-1
D)   4.7 × 10-3 s-1
E)   none of the aboveF) A) and B)
G) C) and E)

Question 4

Is a bimolecular reaction necessarily second-order? Is a second-order reaction necessarily bimolecular? Answer, with explanations and clarifications.

Accepted Answer

For elementary reactions, the order foll...

Question 5

An elementary reaction is a simple, one-step process.

Accepted Answer

A) True 
 B)False

Question 6

A reaction has an activation energy of 195.0 kJ/mol. When the temperature is increased from 200.°C to 220.°C, the rate constant will increase by a factor of

Accepted Answer

A)   1.1.
B)   4.3 × 104.
C)   3.2.
D)   7.5.
E)   none of the above.F) C) and D)
G) B) and E)

Question 7

Which of the following affects the activation energy of a reaction?

Accepted Answer

A)   temperature of the reactants
B)   concentrations of reactants
C)   presence of a catalyst
D)   surface area of reactants
E)   reaction progressF) A) and E)
G) B) and D) C

Question 8

Which one of the following sets of units is appropriate for a second-order rate constant?

Accepted Answer

A)   s-1
B)   mol L-1 s-1
C)   L mol-1 s-1
D)   mol2 L-2 s-1
E)   L2 mol-2 s-1F) B) and E)
G) A) and E)

Question 9

The active ingredient in an over the counter pain killer analgesic decomposes with a rate constant, k = 9.05 × 10-4 day-1. How many days does it take for 15% of the original ingredient to decompose?

Accepted Answer

A)   730 days
B)   414 days
C)   365 days
D)   180 days
E)   78 daysF) A) and B)
G) C) and D)

Question 10

Cyclopropane is converted to propene in a first-order process. The rate constant is 5.4 × 10-2 hr-1. If the initial concentration of cyclopropane is 0.150 M, what will its concentration be after 22.0 hours?

Accepted Answer

A)   0.0457 M
B)   0.105 M
C)   0.127 M
D)   0.492 M
E)   none of the aboveF) B) and E)
G) None of the above

Question 11

Carbon-14 is a radioactive isotope which decays with a half-life of 5730 years. What is the first-order rate constant for its decay, in units of years-1?

Accepted Answer

A)   5.25 × 10-5 years-1
B)   1.21 × 10-4 years-1
C)   1.75 × 10-4 years-1
D)   3.49 × 10-4 years-1
E)   3.97 × 103 years-1F) A) and E)
G) A) and D)

Question 12

Which of the following sets of units could be appropriate for a zero-order rate constant?

Accepted Answer

A)   s-1
B)   L mol-1 s-1
C)   L2 mol-2 s-1
D)   L3 mol-3 s-1
E)   mol L-1 s-1F) None of the above
G) A) and C)

Question 13

For the reaction A(g)  + 2B(g)   2C(g)  + 2D(g) 
The following data were collected at constant temperature. Determine the correct rate law for this reaction.  2C(g)  + 2D(g)  The following data were collected at constant temperature. Determine the correct rate law for this reaction.   A)  Rate = k[A] [B] B)  Rate = k[A]2 [B] C)  Rate = k[A] [B]2 D)  Rate = k[A] E)  Rate = k[A]3" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   Rate = k[A] [B]
B)   Rate = k[A]2 [B]
C)   Rate = k[A] [B]2
D)   Rate = k[A]
E)   Rate = k[A]3F) A) and B)
G) A) and C)

Question 14

You are studying the rate of the reaction 2A F1F1F1S1F1F1F10 B and have obtained measurements of the concentration of A at times t = 100, 200, 300, ......, 1000 seconds from the start of the reaction. Carefully describe how you would plot a graph and use it to
a. prove that the reaction is second-order with respect to A.
b. determine the second-order rate constant k.

Accepted Answer

a. Plot 1/[A] versus time. If ...

Question 15

Sucrose decomposes to fructose and glucose in acid solution. When ln [sucrose] is plotted vs. time, a straight line with slope of -0.208 hr-1 results. What is the rate law for the reaction?

Accepted Answer

A)   Rate = 0.208 hr-1 [sucrose]2
B)   Rate = 0.208 hr-1 [sucrose]
C)   Rate = 0.0433 hr [sucrose]2
D)   Rate = 0.0433 hr [sucrose]
E)   Rate = 0.208 mol L-1hr-1 [sucrose]0F) A) and E)
G) A) and D) B

Question 16

In the gas phase at 500.°C, cyclopropane reacts to form propene in a first-order reaction. The figure shows the natural logarithm of the concentration of cyclopropane (in mol/L) plotted versus time.  a. Explain how this plot confirms that the reaction is first order.
b. Calculate the first-order rate constant, k.
c. Determine the initial concentration of
cyclopropane in this experiment.

Accepted Answer

a. The fact that a plot of ln ...

Question 17

A reaction intermediate is a species corresponding to a local energy maximum on a reaction energy diagram.

Accepted Answer

A) True 
 B)False

Question 18

You are required to determine the energy of activation (Ea) of a reaction. Briefly describe the experimental measurements you would make and how you would obtain the activation energy from a suitable linear plot of the experimental data.

Accepted Answer

Rate constants k over a suitable range of absolute temperatures T. A plot of ln k versus 1/T should be linear, and its slope is - E_a/R.

Question 19

The half-life of a first-order reaction does not depend on the initial concentration of reactant.

Accepted Answer

A) True 
 B)False

Question 20

The greater the energy of activation, Ea, the faster will be the reaction.

Accepted Answer

A) True 
 B)False

Exam 16: Kinetics: Rates and Mechanisms of Chemical Reactions

The rate law for the reaction 3A  2B is rate = k[A] with a rate constant of 0.0447 hr^-1. What is the half-life of the reaction?

Correct Answer
verified

The decomposition of hydrogen peroxide is a first-order process with a rate constant of 1.06 × 10^-3 min^-1. How long will it take for the concentration of H₂O₂to drop from 0.0200 M to 0.0120 M?

Correct Answer
verified

A rate constant obeys the Arrhenius equation, the factor A being 2.2 × 10¹³ s^-1 and the activation energy being 150. kJ mol^-1. What is the value of the rate constant at 227°C, in s^-1?

Correct Answer
verified

Is a bimolecular reaction necessarily second-order? Is a second-order reaction necessarily bimolecular? Answer, with explanations and clarifications.

Correct Answer
verified
For elementary reactions, the order foll...
View Answer

An elementary reaction is a simple, one-step process.

Correct Answer
verified

A reaction has an activation energy of 195.0 kJ/mol. When the temperature is increased from 200.°C to 220.°C, the rate constant will increase by a factor of

Correct Answer
verified

Which of the following affects the activation energy of a reaction?

Correct Answer
verified
C

Which one of the following sets of units is appropriate for a second-order rate constant?

Correct Answer
verified

The active ingredient in an over the counter pain killer analgesic decomposes with a rate constant, k = 9.05 × 10^-4 day^-1. How many days does it take for 15% of the original ingredient to decompose?

Correct Answer
verified

Cyclopropane is converted to propene in a first-order process. The rate constant is 5.4 × 10^-2 hr^-1. If the initial concentration of cyclopropane is 0.150 M, what will its concentration be after 22.0 hours?

Correct Answer
verified

Carbon-14 is a radioactive isotope which decays with a half-life of 5730 years. What is the first-order rate constant for its decay, in units of years^-1?

Correct Answer
verified

Which of the following sets of units could be appropriate for a zero-order rate constant?

Correct Answer
verified

For the reaction A(g) + 2B(g)  2C(g) + 2D(g) The following data were collected at constant temperature. Determine the correct rate law for this reaction.

Correct Answer
verified

Correct Answer
verified
a. Plot 1/[A] versus time. If ...
View Answer

Sucrose decomposes to fructose and glucose in acid solution. When ln [sucrose] is plotted vs. time, a straight line with slope of -0.208 hr^-1 results. What is the rate law for the reaction?

Correct Answer
verified
B

Correct Answer
verified
a. The fact that a plot of ln ...
View Answer

A reaction intermediate is a species corresponding to a local energy maximum on a reaction energy diagram.

Correct Answer
verified

You are required to determine the energy of activation (E_a) of a reaction. Briefly describe the experimental measurements you would make and how you would obtain the activation energy from a suitable linear plot of the experimental data.

Correct Answer
verified
Rate constants k over a suitable range of absolute temperatures T. A plot of ln k versus 1/T should be linear, and its slope is - E_a/R.

The half-life of a first-order reaction does not depend on the initial concentration of reactant.

Correct Answer
verified

The greater the energy of activation, E_a, the faster will be the reaction.

Correct Answer
verified

Exam 16: Kinetics: Rates and Mechanisms of Chemical Reactions

The rate law for the reaction 3A  2B is rate = k[A] with a rate constant of 0.0447 hr-1. What is the half-life of the reaction?

Correct AnswerverifiedShow Answer

The decomposition of hydrogen peroxide is a first-order process with a rate constant of 1.06 × 10-3 min-1. How long will it take for the concentration of H2O2 to drop from 0.0200 M to 0.0120 M?

Correct AnswerverifiedShow Answer

A rate constant obeys the Arrhenius equation, the factor A being 2.2 × 1013 s-1 and the activation energy being 150. kJ mol-1. What is the value of the rate constant at 227°C, in s-1?

Correct AnswerverifiedShow Answer

Is a bimolecular reaction necessarily second-order? Is a second-order reaction necessarily bimolecular? Answer, with explanations and clarifications.

Correct AnswerverifiedFor elementary reactions, the order foll...View AnswerShow Answer

An elementary reaction is a simple, one-step process.

Correct AnswerverifiedShow Answer

A reaction has an activation energy of 195.0 kJ/mol. When the temperature is increased from 200.°C to 220.°C, the rate constant will increase by a factor of

Correct AnswerverifiedShow Answer

Which of the following affects the activation energy of a reaction?

Correct AnswerverifiedC

Which one of the following sets of units is appropriate for a second-order rate constant?

Correct AnswerverifiedShow Answer

The active ingredient in an over the counter pain killer analgesic decomposes with a rate constant, k = 9.05 × 10-4 day-1. How many days does it take for 15% of the original ingredient to decompose?

Correct AnswerverifiedShow Answer

Cyclopropane is converted to propene in a first-order process. The rate constant is 5.4 × 10-2 hr-1. If the initial concentration of cyclopropane is 0.150 M, what will its concentration be after 22.0 hours?

Correct AnswerverifiedShow Answer

Carbon-14 is a radioactive isotope which decays with a half-life of 5730 years. What is the first-order rate constant for its decay, in units of years-1?

Correct AnswerverifiedShow Answer

Which of the following sets of units could be appropriate for a zero-order rate constant?

Correct AnswerverifiedShow Answer

For the reaction A(g) + 2B(g)  2C(g) + 2D(g) The following data were collected at constant temperature. Determine the correct rate law for this reaction.

Correct AnswerverifiedShow Answer

Correct Answerverifieda. Plot 1/[A] versus time. If ...View AnswerShow Answer

Sucrose decomposes to fructose and glucose in acid solution. When ln [sucrose] is plotted vs. time, a straight line with slope of -0.208 hr-1 results. What is the rate law for the reaction?

Correct AnswerverifiedB

Correct Answerverifieda. The fact that a plot of ln ...View AnswerShow Answer

A reaction intermediate is a species corresponding to a local energy maximum on a reaction energy diagram.

Correct AnswerverifiedShow Answer

You are required to determine the energy of activation (Ea) of a reaction. Briefly describe the experimental measurements you would make and how you would obtain the activation energy from a suitable linear plot of the experimental data.

Correct AnswerverifiedRate constants k over a suitable range of absolute temperatures T. A plot of ln k versus 1/T should be linear, and its slope is - Ea/R.

The half-life of a first-order reaction does not depend on the initial concentration of reactant.

Correct AnswerverifiedShow Answer

The greater the energy of activation, Ea, the faster will be the reaction.

Correct AnswerverifiedShow Answer

The rate law for the reaction 3A  2B is rate = k[A] with a rate constant of 0.0447 hr^-1. What is the half-life of the reaction?

Correct Answer
verified

The decomposition of hydrogen peroxide is a first-order process with a rate constant of 1.06 × 10^-3 min^-1. How long will it take for the concentration of H₂O₂to drop from 0.0200 M to 0.0120 M?

Correct Answer
verified

A rate constant obeys the Arrhenius equation, the factor A being 2.2 × 10¹³ s^-1 and the activation energy being 150. kJ mol^-1. What is the value of the rate constant at 227°C, in s^-1?

Correct Answer
verified

Correct Answer
verified
For elementary reactions, the order foll...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
C

Correct Answer
verified

The active ingredient in an over the counter pain killer analgesic decomposes with a rate constant, k = 9.05 × 10^-4 day^-1. How many days does it take for 15% of the original ingredient to decompose?

Correct Answer
verified

Cyclopropane is converted to propene in a first-order process. The rate constant is 5.4 × 10^-2 hr^-1. If the initial concentration of cyclopropane is 0.150 M, what will its concentration be after 22.0 hours?

Correct Answer
verified

Carbon-14 is a radioactive isotope which decays with a half-life of 5730 years. What is the first-order rate constant for its decay, in units of years^-1?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
a. Plot 1/[A] versus time. If ...
View Answer

Sucrose decomposes to fructose and glucose in acid solution. When ln [sucrose] is plotted vs. time, a straight line with slope of -0.208 hr^-1 results. What is the rate law for the reaction?

Correct Answer
verified
B

Correct Answer
verified
a. The fact that a plot of ln ...
View Answer

Correct Answer
verified

You are required to determine the energy of activation (E_a) of a reaction. Briefly describe the experimental measurements you would make and how you would obtain the activation energy from a suitable linear plot of the experimental data.

Correct Answer
verified
Rate constants k over a suitable range of absolute temperatures T. A plot of ln k versus 1/T should be linear, and its slope is - E_a/R.

Correct Answer
verified

The greater the energy of activation, E_a, the faster will be the reaction.

Correct Answer
verified