Question 1

What is the molecularity of the following elementary reaction?
NH2Cl(aq) + OH-(aq)   →	o→ NHCl-(aq) + H2O(l)

Accepted Answer

A)  unimolecular
B)  bimolecular
C)  termolecular
D)  tetramolecular
E)  The reaction order must be known before molecularity can be determined. F) A) and B)
G) C) and D) B

Question 2

According to the collision theory of reaction rates,what are the three requirements which must be met before an elementary reaction between two molecules can occur?

Accepted Answer

Molecules must collide with ea...

Question 3

In the collision theory of reaction rates,the rate constant for a bimolecular reaction can be written as
k = z·p·exp(-Ea/RT)
In one sentence each,clearly explain the physical meaning (interpretation)of the following three factors which appear in the above expression:
a.z
b.p
c.exp(-Ea/RT)

Accepted Answer

a.z is a collision rate constant,such th...

Question 4

A reaction has the following rate law:
Rate = k[A][B]2
 In experiment 1,the concentrations of A and B are both 0.10 mol L-1;in experiment 2,the concentrations are both 0.30 mol L-1.If the temperature stays constant,what is the value of the ratio,Rate(2) /Rate(1) ?

Accepted Answer

A)  3.0
B)  6.0
C)  9.0
D)  18
E)  27F) A) and C)
G) None of the above

Question 5

Cyclobutane decomposes to ethene in a first-order reaction.From measurements of the rate constant (k)at various absolute temperatures (T),the accompanying Arrhenius plot was obtained (ln k versus 1/T).
a.Calculate the energy of activation,Ea.
b.Determine the value of the rate constant at 740.K.(In the plot,the units of k are s-1. )

Accepted Answer

a.260 ± 20 kJ/mol
b....

Question 6

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

Obtain rate constants k over a...

Question 7

All bimolecular reactions are second-order reactions.

Accepted Answer

A) True 
 B)False

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

For the reaction
A(g) + 2B(g)   →	o→  2C(g) + 2D(g) 
The following data was collected at constant temperature.Determine the correct rate law for this reaction.
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]3 F) A) and E)
G) B) and D)

Question 10

For each of the following terms/concepts,give a brief explanation or definition.Where possible,use examples.
a.order of a reaction
b.elementary reaction
c.reaction intermediate

Accepted Answer

a.Order refers to the power to which the...

Question 11

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) C) and D)
G) D) and E)

Question 12

At 25.0°C,a rate constant has the value 5.21 $\times$ 10-8 L mol-1 s-1.If the activation energy is 75.2 kJ/mol,calculate the rate constant when the temperature is 50.0°C.

Accepted Answer

5.44 <img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30"> 10<s...

Question 13

The gas-phase reaction CH3NC  →	o→  CH3CN has been studied in a closed vessel,and the rate equation was found to be: rate = - Δ\DeltaΔ [CH3NC]/ Δ\DeltaΔ t = k[CH3NC].Which one of the following actions is least likely to cause a change in the rate of the reaction?

Accepted Answer

A)  lowering the temperature
B)  adding a catalyst
C)  using a larger initial amount of CH3NC in the same vessel
D)  using a bigger vessel,but the same initial amount of CH3NC
E)  continuously removing CH3CN as it is formed F) B) and E)
G) A) and D) E

Question 14

Reaction intermediates differ from activated complexes in that

Accepted Answer

A)  they are stable molecules with normal bonds and are frequently isolated.
B)  they are molecules with normal bonds rather than partial bonds and can occasionally be isolated.
C)  they are intermediate structures which have characteristics of both reactants and products.
D)  they are unstable and can never be isolated.
E)  all reactions involve reaction intermediates,but not all have activated complexes.F) B) and D)
G) A) and D)

Question 15

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 D)
G) A) and B)

Question 16

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

Question 17

A rate constant obeys the Arrhenius equation,the factor A being 2.2  ×	imes×  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  ×	imes×  1013 s-1
B)  6.7  ×	imes×  10-22 s-1
C)  1.5  ×	imes×  1011 s-1
D)  4.7  ×	imes×  10-3 s-1
E)  None of these choices is correct. F) All of the above
G) B) and D) D

Question 18

Butadiene,C4H6 (used to make synthetic rubber and latex paints) dimerizes to C8H12 with a rate law of rate = 0.014 L/(mol·s) [C4H6]2.What will be the concentration of C4H6 after 3.0 hours if the initial concentration is 0.025 M?

Accepted Answer

A)  0.0052 M
B)  0.024 M
C)  43 M
D)  190 M
E)  0.0000 MF) None of the above
G) B) and E)

Question 19

If the activation energy of a reaction decreases by 10.0 kJ/mol,from 100.0 to 90.0 kJ/mol,what effect will this have on the rate of reaction at 298K?

Accepted Answer

A)  The rate will increase,by a factor of more than 50.
B)  The rate will decrease,by a factor of more than 50.
C)  The rate will increase,by a factor of less than 50.
D)  The rate will decrease,by a factor of less than 50.
E)  The rate will not change unless temperature changes.F) A) and E)
G) A) and D)

Question 20

The decomposition of hydrogen peroxide is a first-order process with a rate constant of 1.06  ×	imes×  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 min F) A) and B)
G) None of the above

Exam 16: Kinetics: Rates and Mechanisms of Chemical Reactions

What is the molecularity of the following elementary reaction? NH₂Cl(aq) + OH^-(aq) $\to$ NHCl^-(aq) + H₂O(l)

Correct Answer
verified
B

According to the collision theory of reaction rates,what are the three requirements which must be met before an elementary reaction between two molecules can occur?

Correct Answer
verified
Molecules must collide with ea...
View Answer

In the collision theory of reaction rates,the rate constant for a bimolecular reaction can be written as k = z·p·exp(-E_a/RT) In one sentence each,clearly explain the physical meaning (interpretation)of the following three factors which appear in the above expression: a.z b.p c.exp(-E_a/RT)

Correct Answer
verified
a.z is a collision rate constant,such th...
View Answer

A reaction has the following rate law: Rate = k[A][B]² In experiment 1,the concentrations of A and B are both 0.10 mol L^-1;in experiment 2,the concentrations are both 0.30 mol L^-1.If the temperature stays constant,what is the value of the ratio,Rate(2) /Rate(1) ?

Correct Answer
verified

Correct Answer
verified
a.260 ± 20 kJ/mol
b....
View Answer

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
Obtain rate constants k over a...
View Answer

All bimolecular reactions are second-order reactions.

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

For each of the following terms/concepts,give a brief explanation or definition.Where possible,use examples. a.order of a reaction b.elementary reaction c.reaction intermediate

Correct Answer
verified
a.Order refers to the power to which the...
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

At 25.0°C,a rate constant has the value 5.21 $\times$ 10^-8 L mol^-1 s^-1.If the activation energy is 75.2 kJ/mol,calculate the rate constant when the temperature is 50.0°C.

Correct Answer
verified
5.44 10
View Answer

The gas-phase reaction CH₃NC $\to$ CH₃CN has been studied in a closed vessel,and the rate equation was found to be: rate = - $\Delta$ [CH₃NC]/ $\Delta$ t = k[CH₃NC].Which one of the following actions is least likely to cause a change in the rate of the reaction?

Correct Answer
verified
E

Reaction intermediates differ from activated complexes in that

Correct Answer
verified

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

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

A rate constant obeys the Arrhenius equation,the factor A being 2.2 $\times$ 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
D

Butadiene,C₄H₆ (used to make synthetic rubber and latex paints) dimerizes to C₈H₁₂ with a rate law of rate = 0.014 L/(mol·s) [C₄H₆]².What will be the concentration of C₄H₆ after 3.0 hours if the initial concentration is 0.025 M?

Correct Answer
verified

If the activation energy of a reaction decreases by 10.0 kJ/mol,from 100.0 to 90.0 kJ/mol,what effect will this have on the rate of reaction at 298K?

Correct Answer
verified

The decomposition of hydrogen peroxide is a first-order process with a rate constant of 1.06 $\times$ 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 Answer
verified

Exam 16: Kinetics: Rates and Mechanisms of Chemical Reactions

What is the molecularity of the following elementary reaction? NH2Cl(aq) + OH-(aq) →\to→ NHCl-(aq) + H2O(l)

Correct AnswerverifiedB

According to the collision theory of reaction rates,what are the three requirements which must be met before an elementary reaction between two molecules can occur?

Correct AnswerverifiedMolecules must collide with ea...View AnswerShow Answer

In the collision theory of reaction rates,the rate constant for a bimolecular reaction can be written as k = z·p·exp(-Ea/RT) In one sentence each,clearly explain the physical meaning (interpretation)of the following three factors which appear in the above expression: a.z b.p c.exp(-Ea/RT)

Correct Answerverifieda.z is a collision rate constant,such th...View AnswerShow Answer

A reaction has the following rate law: Rate = k[A][B]2 In experiment 1,the concentrations of A and B are both 0.10 mol L-1;in experiment 2,the concentrations are both 0.30 mol L-1.If the temperature stays constant,what is the value of the ratio,Rate(2) /Rate(1) ?

Correct AnswerverifiedShow Answer

Correct Answerverifieda.260 ± 20 kJ/molb....View AnswerShow 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 AnswerverifiedObtain rate constants k over a...View AnswerShow Answer

All bimolecular reactions are second-order reactions.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

For each of the following terms/concepts,give a brief explanation or definition.Where possible,use examples. a.order of a reaction b.elementary reaction c.reaction intermediate

Correct Answerverifieda.Order refers to the power to which the...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 AnswerverifiedShow Answer

At 25.0°C,a rate constant has the value 5.21 ×\times× 10-8 L mol-1 s-1.If the activation energy is 75.2 kJ/mol,calculate the rate constant when the temperature is 50.0°C.

Correct Answerverified5.44 10View AnswerShow Answer

The gas-phase reaction CH3NC →\to→ CH3CN has been studied in a closed vessel,and the rate equation was found to be: rate = - Δ\DeltaΔ [CH3NC]/ Δ\DeltaΔ t = k[CH3NC].Which one of the following actions is least likely to cause a change in the rate of the reaction?

Correct AnswerverifiedE

Reaction intermediates differ from activated complexes in that

Correct AnswerverifiedShow Answer

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

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

A rate constant obeys the Arrhenius equation,the factor A being 2.2 ×\times× 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 AnswerverifiedD

Butadiene,C4H6 (used to make synthetic rubber and latex paints) dimerizes to C8H12 with a rate law of rate = 0.014 L/(mol·s) [C4H6]2.What will be the concentration of C4H6 after 3.0 hours if the initial concentration is 0.025 M?

Correct AnswerverifiedShow Answer

If the activation energy of a reaction decreases by 10.0 kJ/mol,from 100.0 to 90.0 kJ/mol,what effect will this have on the rate of reaction at 298K?

Correct AnswerverifiedShow Answer

The decomposition of hydrogen peroxide is a first-order process with a rate constant of 1.06 ×\times× 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

What is the molecularity of the following elementary reaction? NH₂Cl(aq) + OH^-(aq) $\to$ NHCl^-(aq) + H₂O(l)

Correct Answer
verified
B

Correct Answer
verified
Molecules must collide with ea...
View Answer

In the collision theory of reaction rates,the rate constant for a bimolecular reaction can be written as k = z·p·exp(-E_a/RT) In one sentence each,clearly explain the physical meaning (interpretation)of the following three factors which appear in the above expression: a.z b.p c.exp(-E_a/RT)

Correct Answer
verified
a.z is a collision rate constant,such th...
View Answer

A reaction has the following rate law: Rate = k[A][B]² In experiment 1,the concentrations of A and B are both 0.10 mol L^-1;in experiment 2,the concentrations are both 0.30 mol L^-1.If the temperature stays constant,what is the value of the ratio,Rate(2) /Rate(1) ?

Correct Answer
verified

Correct Answer
verified
a.260 ± 20 kJ/mol
b....
View Answer

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
Obtain rate constants k over a...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
a.Order refers to the power to which the...
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

At 25.0°C,a rate constant has the value 5.21 $\times$ 10^-8 L mol^-1 s^-1.If the activation energy is 75.2 kJ/mol,calculate the rate constant when the temperature is 50.0°C.

Correct Answer
verified
5.44 10
View Answer

The gas-phase reaction CH₃NC $\to$ CH₃CN has been studied in a closed vessel,and the rate equation was found to be: rate = - $\Delta$ [CH₃NC]/ $\Delta$ t = k[CH₃NC].Which one of the following actions is least likely to cause a change in the rate of the reaction?

Correct Answer
verified
E

Correct Answer
verified

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

A rate constant obeys the Arrhenius equation,the factor A being 2.2 $\times$ 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
D

Butadiene,C₄H₆ (used to make synthetic rubber and latex paints) dimerizes to C₈H₁₂ with a rate law of rate = 0.014 L/(mol·s) [C₄H₆]².What will be the concentration of C₄H₆ after 3.0 hours if the initial concentration is 0.025 M?

Correct Answer
verified

Correct Answer
verified

The decomposition of hydrogen peroxide is a first-order process with a rate constant of 1.06 $\times$ 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 Answer
verified