Question 1

Based on the initial rate data below, what is the value of the rate constant? 2NOBr(g)   →\rightarrow→ 2NO(g)  + Br2(g)  2(g)    A)  0.0360 L mol¯1s¯1 B)  0.800 L mol¯1s¯1 C)  1.25 L mol¯1s¯1 D)  27.8 L mol¯1s¯1 E)  0.0360 s¯1 " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   0.0360 L mol¯1s¯1
B)   0.800 L mol¯1s¯1
C)   1.25 L mol¯1s¯1
D)   27.8 L mol¯1s¯1
E)   0.0360 s¯1 F) B) and C)
G) A) and C)

Question 2

In the gas phase at 500.$\degree$C, cyclopropane reacts to form propene in a first-order reaction. The figure below shows the concentration of cyclopropane plotted versus time. Use the graph to calculate approximate values of
A) the rate of the reaction, 600. seconds after the start.
B) the half-life of the reaction, t1/2.

Accepted Answer

a. Rate = - slope = ...

Question 3

In the collision theory of reaction rates, the rate constant for a bimolecular reaction can be written as k = z · p · exp  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

Accepted Answer

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

Question 4

The rate constant for the reaction 3A  →\rightarrow→  4B is 6.00 *10¯3 L mol¯1min¯1. How long will it take the concentration of A to drop from 0.75 M to 0.25 M?

Accepted Answer

A)   2.2 * 10¯3 min
B)   5.5 * 10¯3 min
C)   180 min
D)   440 min
E)   5.0 * 102 min F) C) and E)
G) A) and C)

Question 5

Consider the following mechanism for the oxidation of bromide ions by hydrogen peroxide in aqueous acid solution. 2O+     OH + 2Br¯  \rightarrow H2O2 + Br2 + 2H2O B)  2H+ + 2Br¯ + H2O2  \rightarrow  Br2 + 2H2O C)  2H+ + H2O2 + Br¯ + HOBr  \rightarrow H2O+     OH + Br2 + H2O D)  H2O+     OH + Br¯ + H+  \rightarrow  Br2 + H2O E)  None of these choices is correct. " class="answers-bank-image d-inline" rel="preload" > What is the overall reaction equation for this process?

Accepted Answer

A)   2H2O+  2O+     OH + 2Br¯  \rightarrow H2O2 + Br2 + 2H2O 
B)   2H+ + 2Br¯ + H2O2  \rightarrow  Br2 + 2H2O 
C)   2H+ + H2O2 + Br¯ + HOBr  \rightarrow H2O+     OH + Br2 + H2O 
D)   H2O+     OH + Br¯ + H+  \rightarrow  Br2 + H2O 
E)   None of these choices is correct. " class="answers-bank-image d-inline" rel="preload" > OH + 2Br¯  →\rightarrow→ H2O2 + Br2 + 2H2O
B)   2H+ + 2Br¯ + H2O2  →\rightarrow→  Br2 + 2H2O
C)   2H+ + H2O2 + Br¯ + HOBr  →\rightarrow→ H2O+  2O+     OH + 2Br¯  \rightarrow H2O2 + Br2 + 2H2O 
B)   2H+ + 2Br¯ + H2O2  \rightarrow  Br2 + 2H2O 
C)   2H+ + H2O2 + Br¯ + HOBr  \rightarrow H2O+     OH + Br2 + H2O 
D)   H2O+     OH + Br¯ + H+  \rightarrow  Br2 + H2O 
E)   None of these choices is correct. " class="answers-bank-image d-inline" rel="preload" > OH + Br2 + H2O
D)   H2O+  2O+     OH + 2Br¯  \rightarrow H2O2 + Br2 + 2H2O 
B)   2H+ + 2Br¯ + H2O2  \rightarrow  Br2 + 2H2O 
C)   2H+ + H2O2 + Br¯ + HOBr  \rightarrow H2O+     OH + Br2 + H2O 
D)   H2O+     OH + Br¯ + H+  \rightarrow  Br2 + H2O 
E)   None of these choices is correct. " class="answers-bank-image d-inline" rel="preload" > OH + Br¯ + H+  →\rightarrow→  Br2 + H2O
E)   None of these choices is correct. F) B) and E)
G) A) and C)

Question 6

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 C)

Question 7

Consider this reaction: 8A(g)  + 5B(g)   →\rightarrow→ 8C(g)  + 6D(g)  If [C] is increasing at the rate of 4.0 mol L¯1s¯1, at what rate is [B] changing?

Accepted Answer

A)   -0.40 mol L¯1s¯1
B)   -2.5 mol L¯1s¯1
C)   -4.0 mol L¯1s¯1
D)   -6.4 mol L¯1s¯1
E)   None of these choices is correct, since its rate of change must be positive. F) B) and C)
G) A) and E)

Question 8

The rate constant for a reaction is 4.65 L mol¯1s¯1. What is the overall order of the reaction?

Accepted Answer

A)   zero
B)   first
C)   second
D)   third
E)   More information is needed to determine the overall order.F) D) and E)
G) B) and C)

Question 9

The decomposition of dinitrogen pentaoxide to nitrogen dioxide and oxygen follows first-order kinetics and has an activation energy of 102 kJ/mol. By what factor will the fraction of collisions with energy greater than or equal to the activation energy increase if the reaction temperature goes from 30  °\degree° C to 60  °\degree° C?

Accepted Answer

A)   1.00
B)   1.10
C)   2.00
D)   4.00
E)   38.4 F) A) and B)
G) B) and D)

Exam 16: Kinetics: Rates and Mechanisms of Chemical Reactions

Correct Answer
verified
a. Rate = - slope = ...
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Correct Answer
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The rate constant for the reaction 3A $\rightarrow$ 4B is 6.00 *10¯³ L mol¯¹min¯¹. How long will it take the concentration of A to drop from 0.75 M to 0.25 M?

Correct Answer
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Correct Answer
verified

In the collision theory of reaction rates, the rate constant for a bimolecular reaction can be written as k = z · p · exp 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

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

Consider this reaction: 8A(g) + 5B(g) $\rightarrow$ 8C(g) + 6D(g) If [C] is increasing at the rate of 4.0 mol L¯¹s¯¹, at what rate is [B] changing?

Correct Answer
verified

The rate constant for a reaction is 4.65 L mol¯¹s¯¹. What is the overall order of the reaction?

Correct Answer
verified

Correct Answer
verified

Exam 16: Kinetics: Rates and Mechanisms of Chemical Reactions

Correct Answerverifieda. Rate = - slope = ...View AnswerShow Answer

Based on the initial rate data below, what is the value of the rate constant? 2NOBr(g) →\rightarrow→ 2NO(g) + Br2(g)

Correct AnswerverifiedShow Answer

The rate constant for the reaction 3A →\rightarrow→ 4B is 6.00 *10¯3 L mol¯1min¯1. How long will it take the concentration of A to drop from 0.75 M to 0.25 M?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In the collision theory of reaction rates, the rate constant for a bimolecular reaction can be written as k = z · p · exp 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

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

Consider this reaction: 8A(g) + 5B(g) →\rightarrow→ 8C(g) + 6D(g) If [C] is increasing at the rate of 4.0 mol L¯1s¯1, at what rate is [B] changing?

Correct AnswerverifiedShow Answer

The rate constant for a reaction is 4.65 L mol¯1s¯1. What is the overall order of the reaction?

Correct AnswerverifiedShow Answer

Consider the following mechanism for the oxidation of bromide ions by hydrogen peroxide in aqueous acid solution. What is the overall reaction equation for this process?

Correct AnswerverifiedShow Answer

Correct Answer
verified
a. Rate = - slope = ...
View Answer

Correct Answer
verified

The rate constant for the reaction 3A $\rightarrow$ 4B is 6.00 *10¯³ L mol¯¹min¯¹. How long will it take the concentration of A to drop from 0.75 M to 0.25 M?

Correct Answer
verified

Correct Answer
verified

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

Consider this reaction: 8A(g) + 5B(g) $\rightarrow$ 8C(g) + 6D(g) If [C] is increasing at the rate of 4.0 mol L¯¹s¯¹, at what rate is [B] changing?

Correct Answer
verified

The rate constant for a reaction is 4.65 L mol¯¹s¯¹. What is the overall order of the reaction?

Correct Answer
verified

Correct Answer
verified