Question 1

Given:
2O3(g)  →\rightarrow→ 3O2(g) 
Rate = k[O3]2[O2]-1
The overall order of the reaction and the order with respect to [O3] are

Accepted Answer

A)   -1 and 3.
B)   1 and 2.
C)   0 and 1.
D)   2 and 2.
E)   3 and 2.

Question 2

A possible mechanism for the reaction 2NO(g)  + O2(g)  →\rightarrow→ 2NO2(g) 
Is:
2NO(g)  
 fff 
N2O2(g) 
K1,K1',Fast
N2O2(g) + O2(g)  →\rightarrow→  2NO2(g) 
K2,Slow
Application of the steady-state approximation gives

Accepted Answer

A)   [N2O2] = 0.
B)   k1[NO]2 - k2[N2O2][O2] = 0.
C)   [N2O2] = (k1/k2) [NO]2. 
D)   k1[NO]2 - k1'[N2O2] -k2[N2O2][O2] = 0.
E)   [N2O2] = (k1/k1') [NO]2.   D

Question 3

Consider the reaction
2A $\rightarrow$ B,Rate = k[A]2
If the rate of disappearance of A is followed,derive the experimental rate constant.

Accepted Answer

2k; the numerical va...

Question 4

For the proposed mechanism
A + X 
 fff 
B k1,K-1 (fast) 
B  →\rightarrow→  products k2 (slow) 
What is the rate law?

Accepted Answer

A)   rate = (k1k-1) [A][X]
B)   rate = k2[B]
C)   rate = (k1/k2) [A]
D)   rate = (k1k2/ k-1) [A]
E)   rate = (k1k2/ k-1) [A][X]

Question 5

Given: A + B  →\rightarrow→  P rate = k[A][B]
Which of the following is true?

Accepted Answer

A)   k = ln 2/t1/2
B)   ln [A]t = -kt + ln [A]o
C)   [A]t = [A]o/(1 + kt[A]o) 
D)   1/[A]t = 1/kt

Question 6

Given: A  →\rightarrow→  P rate = k[A]
If 20% of A reacts in 5.12 min,Calculate the time required for 90% of A to react.

Accepted Answer

A)   52.8 min
B)   1.05 min
C)   2.42 min
D)   3170 min
E)   22.9 min  A

Question 7

A first-order reaction has a half-life of 1.10 s .If the initial concentration of reactant is 0.384 M,How long will it take for the reactant concentration to reach 0.00100 M?

Accepted Answer

A)   9.45 s
B)   0.106 s
C)   4.10 s
D)   1.52 s
E)   0.244 s

Question 8

The reaction profile for the reaction
[(CN)5CoOH2]2-(aq)+ SCN-(aq)$\rightarrow$[(CN)5CoSCN]3- + H2O(l)
is  
Identify the structure of B.What do A and C represent?

Accepted Answer

B = [(CN)₅

Question 9

For the reaction cyclopropane(g)$\rightarrow$ propene(g)at 500$\omicron$C,a plot of ln[cyclopropane] vs t gives a straight line with a slope of -0.00067 s-1.What is the order of this reaction and what is the rate constant?

Accepted Answer

first-order,
6.7 * 1...

Question 10

The reaction
2NO(g) + 2H2(g)  →\rightarrow→ N2(g) + 2H2O(g) 
Is first order in H2 and second order in NO.Starting with equal concentrations of H2 and NO,The rate after 50% of the H2 has reacted is what percent of the initial rate?

Accepted Answer

A)   18.8%
B)   37.5%
C)   25.0%
D)   50.0%
E)   12.5%

Question 11

Consider the reaction below.
2A + B2  →\rightarrow→  2AB Rate = k[A]2[B]
Which of the following mechanisms is likely and consistent with the experimental rate law?
1.A + A + B2 →\rightarrow→  2AB
2.B2 
 fff 
2B     K,Fast
A + B  →\rightarrow→  AB   k,Slow"
3.B2  →\rightarrow→  2B    k1,Slow
A + B  →\rightarrow→  AB k2,Fast"
4.2A 
 fff 
A2 K,Fast
B2 + A2  →\rightarrow→  2AB k,Slow"

Accepted Answer

A)   2
B)   3
C)   4
D)   1
E)   2 and 3

Question 12

The reaction 2A + B $\rightarrow$ D + E has the rate law,rate = a[A]2[B]/(b + c[A]) where a,b,and c are constants.The following mechanism has been proposed for this reaction.
A + B 
k1,k-1
$f$ 
I
I + A $\rightarrow$ D + E
k2
I is an unstable intermediate present in minute concentrations.Show that this mechanism leads to the observed rate law and evaluate the constantsa,b,and c in terms of the rate constants k1,k-1,and k2.

Accepted Answer

a = k₁k₂...

Question 13

Consider the mechanism
NO2(g) + F2(g)  →\rightarrow→ NO2F(g) + F(g)    K1 (slow) 
F(g) + NO2(g)  →\rightarrow→  NO2F(g)   K2 (fast) 
Give the molecularity of the first step and any intermediates in the mechanism.

Accepted Answer

A)   2, and F(g) 
B)   2, and NO2F(g) 
C)   2, and NO2(g) 
D)   1, and no intermediate
E)   2, and no intermediate  A

Question 14

The rate law for a reaction can be determined from the coefficients in the overall reaction.

Accepted Answer

A) True 
 B)False

Question 15

For the elementary reaction A + 2B $\rightarrow$ products, rate = k[A][B].

Accepted Answer

A) True 
 B)False

Question 16

For the reaction cyclobutane(g)   →\rightarrow→  2ethylene(g) At 800 K,A plot of ln[cyclobutane] vs t gives a straight line with a slope of -1.6 s-1.Calculate the time needed for the concentration of cyclobutane to fall to 1/16 of its initial value.

Accepted Answer

A)   2.3 s
B)   1.7 s
C)   1.3 s
D)   0.63 s
E)   1.6 s

Question 17

For the reaction
Cyclopropane →\rightarrow→ propene
A plot of ln[cyclopropane] vs time in seconds gives a straight line with slope -4.1 * 10-3 s-1 at 550 ο\omicronο C.What is the rate constant for this reaction?

Accepted Answer

A)   3.9 * 10-2 s-1 
B)   8.2 * 10-3 s-1 
C)   4.1 * 10-3 s-1 
D)   1.8 * 10-3 s-1 
E)   2.1 * 10-3 s-1

Question 18

The HBr synthesis is thought to involve the following reactions:
1.Br2  →\rightarrow→ 2Br.
2.Br. + H2  →\rightarrow→  HBr + H.
3.H. + Br2  →\rightarrow→  HBr + Br.
4.2Br. →\rightarrow→ Br2
5.2H.  →\rightarrow→  H2
6.H. + Br.  →\rightarrow→  HBr
The chain propagation reactions in this mechanism are reactions"

Accepted Answer

A)   6.
B)   1, 2, 3, and 6.
C)   2 and 3.
D)   1, 2, and 3.
E)   2, 3, and 6.

Question 19

The reaction 2NO(g)  + O2(g)  →\rightarrow→  2NO2(g)  Has  Δ\DeltaΔ Hr ο\omicronο  = -4 kJ.mol-1.
A possible mechanism for this reaction is
2NO(g)  Rapid equilibrium,K
 fff 
N2O2(g) 
N2O2(g) +O2(g)  →\rightarrow→ 2NO2(g) 
Slow,K
If the activation energy for the reverse reaction is 225 kJ.mol-1.
What is the activation energy for the forward reaction?

Accepted Answer

A)   Because an intermediate is involved, the forward activation energy cannot be calculated with the given information.
B)   111 kJ.mol-1.
C)   339 kJ.mol-1.
D)   114 kJ.mol-1.
E)   55.5 kJ.mol-1.

Question 20

For the reaction S2O82-(aq)  + 3I-(aq)  →\rightarrow→ 2SO42-(aq) + I3-(aq) ,
Rate =k[S2O82-][I-].When the reaction is followed under pseudo-first-order conditions with [S2O82-] = 200 m M and [I-] = 1.5 m M,
The rate constant was 1.82 s-1.The second order rate constant,K,For the reaction is

Accepted Answer

A)   1.21 * 103 M-1.s-1.
B)   6.07 * 103 M-1.s-1.
C)   9.10 M-1.s-1.
D)   1.37 * 10-2 M-1.s-1.
E)   1.82 M-1.s-1..

Exam 7: Kinetics

Given: 2O₃(g) $\rightarrow$ 3O₂(g) Rate = k[O₃]²[O₂]^-¹ The overall order of the reaction and the order with respect to [O₃] are

Correct Answer
verified

A possible mechanism for the reaction 2NO(g) + O₂(g) $\rightarrow$ 2NO₂(g) Is: 2NO(g) $f$ N₂O₂(g) K₁,K₁',Fast N₂O₂(g) + O₂(g) $\rightarrow$ 2NO₂(g) K₂,Slow Application of the steady-state approximation gives

Correct Answer
verified
D

Consider the reaction 2A $\rightarrow$ B,Rate = k[A]² If the rate of disappearance of A is followed,derive the experimental rate constant.

Correct Answer
verified
2k; the numerical va...
View Answer

For the proposed mechanism A + X $f$ B k₁,K_-1(fast) B $\rightarrow$ products k₂ (slow) What is the rate law?

Correct Answer
verified

Given: A + B $\rightarrow$ P rate = k[A][B] Which of the following is true?

Correct Answer
verified

Given: A $\rightarrow$ P rate = k[A] If 20% of A reacts in 5.12 min,Calculate the time required for 90% of A to react.

Correct Answer
verified
A

A first-order reaction has a half-life of 1.10 s .If the initial concentration of reactant is 0.384 M,How long will it take for the reactant concentration to reach 0.00100 M?

Correct Answer
verified

Correct Answer
verified
B = [(CN)_{5View Answer}

For the reaction cyclopropane(g) $\rightarrow$ propene(g)at 500^$\omicron$C,a plot of ln[cyclopropane] vs t gives a straight line with a slope of -0.00067 s^-¹.What is the order of this reaction and what is the rate constant?

Correct Answer
verified
first-order,
6.7 * 1...
View Answer

The reaction 2NO(g) + 2H₂(g) $\rightarrow$ N₂(g) + 2H₂O(g) Is first order in H₂ and second order in NO.Starting with equal concentrations of H₂ and NO,The rate after 50% of the H₂ has reacted is what percent of the initial rate?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
a = k₁k₂...
View Answer

Consider the mechanism NO₂(g) + F₂(g) $\rightarrow$ NO₂F(g) + F(g) K₁ (slow) F(g) + NO₂(g) $\rightarrow$ NO₂F(g) K₂ (fast) Give the molecularity of the first step and any intermediates in the mechanism.

Correct Answer
verified
A

The rate law for a reaction can be determined from the coefficients in the overall reaction.

Correct Answer
verified

For the elementary reaction A + 2B $\rightarrow$ products, rate = k[A][B].

Correct Answer
verified

For the reaction cyclobutane(g) $\rightarrow$ 2ethylene(g) At 800 K,A plot of ln[cyclobutane] vs t gives a straight line with a slope of -1.6 s^-¹.Calculate the time needed for the concentration of cyclobutane to fall to 1/16 of its initial value.

Correct Answer
verified

For the reaction Cyclopropane $\rightarrow$ propene A plot of ln[cyclopropane] vs time in seconds gives a straight line with slope -4.1 * 10^-³ s^-¹ at 550^$\omicron$C.What is the rate constant for this reaction?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Exam 7: Kinetics

Given: 2O3(g) →\rightarrow→ 3O2(g) Rate = k[O3]2[O2]-1 The overall order of the reaction and the order with respect to [O3] are

Correct AnswerverifiedShow Answer

A possible mechanism for the reaction 2NO(g) + O2(g) →\rightarrow→ 2NO2(g) Is: 2NO(g) fff N2O2(g) K1,K1',Fast N2O2(g) + O2(g) →\rightarrow→ 2NO2(g) K2,Slow Application of the steady-state approximation gives

Correct AnswerverifiedD

Consider the reaction 2A →\rightarrow→ B,Rate = k[A]2 If the rate of disappearance of A is followed,derive the experimental rate constant.

Correct Answerverified2k; the numerical va...View AnswerShow Answer

For the proposed mechanism A + X fff B k1,K-1 (fast) B →\rightarrow→ products k2 (slow) What is the rate law?

Correct AnswerverifiedShow Answer

Given: A + B →\rightarrow→ P rate = k[A][B] Which of the following is true?

Correct AnswerverifiedShow Answer

Given: A →\rightarrow→ P rate = k[A] If 20% of A reacts in 5.12 min,Calculate the time required for 90% of A to react.

Correct AnswerverifiedA

A first-order reaction has a half-life of 1.10 s .If the initial concentration of reactant is 0.384 M,How long will it take for the reactant concentration to reach 0.00100 M?

Correct AnswerverifiedShow Answer

The reaction profile for the reaction [(CN)5CoOH2]2-(aq)+ SCN-(aq) →\rightarrow→ [(CN)5CoSCN]3- + H2O(l) is Identify the structure of B.What do A and C represent?

Correct AnswerverifiedB = [(CN)5View AnswerShow Answer

For the reaction cyclopropane(g) →\rightarrow→ propene(g)at 500 ο\omicronο C,a plot of ln[cyclopropane] vs t gives a straight line with a slope of -0.00067 s-1.What is the order of this reaction and what is the rate constant?

Correct Answerverifiedfirst-order,6.7 * 1...View AnswerShow Answer

The reaction 2NO(g) + 2H2(g) →\rightarrow→ N2(g) + 2H2O(g) Is first order in H2 and second order in NO.Starting with equal concentrations of H2 and NO,The rate after 50% of the H2 has reacted is what percent of the initial rate?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct Answerverifieda = k1k2...View AnswerShow Answer

Consider the mechanism NO2(g) + F2(g) →\rightarrow→ NO2F(g) + F(g) K1 (slow) F(g) + NO2(g) →\rightarrow→ NO2F(g) K2 (fast) Give the molecularity of the first step and any intermediates in the mechanism.

Correct AnswerverifiedA

The rate law for a reaction can be determined from the coefficients in the overall reaction.

Correct AnswerverifiedShow Answer

For the elementary reaction A + 2B →\rightarrow→ products, rate = k[A][B].

Correct AnswerverifiedShow Answer

For the reaction cyclobutane(g) →\rightarrow→ 2ethylene(g) At 800 K,A plot of ln[cyclobutane] vs t gives a straight line with a slope of -1.6 s-1.Calculate the time needed for the concentration of cyclobutane to fall to 1/16 of its initial value.

Correct AnswerverifiedShow Answer

For the reaction Cyclopropane →\rightarrow→ propene A plot of ln[cyclopropane] vs time in seconds gives a straight line with slope -4.1 * 10-3 s-1 at 550 ο\omicronο C.What is the rate constant for this reaction?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

For the reaction S2O82-(aq) + 3I-(aq) →\rightarrow→ 2SO42-(aq) + I3-(aq) , Rate =k[S2O82-][I-].When the reaction is followed under pseudo-first-order conditions with [S2O82-] = 200 m M and [I-] = 1.5 m M, The rate constant was 1.82 s-1.The second order rate constant,K,For the reaction is

Correct AnswerverifiedShow Answer

Given: 2O₃(g) $\rightarrow$ 3O₂(g) Rate = k[O₃]²[O₂]^-¹ The overall order of the reaction and the order with respect to [O₃] are

Correct Answer
verified

A possible mechanism for the reaction 2NO(g) + O₂(g) $\rightarrow$ 2NO₂(g) Is: 2NO(g) $f$ N₂O₂(g) K₁,K₁',Fast N₂O₂(g) + O₂(g) $\rightarrow$ 2NO₂(g) K₂,Slow Application of the steady-state approximation gives

Correct Answer
verified
D

Consider the reaction 2A $\rightarrow$ B,Rate = k[A]² If the rate of disappearance of A is followed,derive the experimental rate constant.

Correct Answer
verified
2k; the numerical va...
View Answer

For the proposed mechanism A + X $f$ B k₁,K_-1(fast) B $\rightarrow$ products k₂ (slow) What is the rate law?

Correct Answer
verified

Given: A + B $\rightarrow$ P rate = k[A][B] Which of the following is true?

Correct Answer
verified

Given: A $\rightarrow$ P rate = k[A] If 20% of A reacts in 5.12 min,Calculate the time required for 90% of A to react.

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified
B = [(CN)_{5View Answer}

For the reaction cyclopropane(g) $\rightarrow$ propene(g)at 500^$\omicron$C,a plot of ln[cyclopropane] vs t gives a straight line with a slope of -0.00067 s^-¹.What is the order of this reaction and what is the rate constant?

Correct Answer
verified
first-order,
6.7 * 1...
View Answer

The reaction 2NO(g) + 2H₂(g) $\rightarrow$ N₂(g) + 2H₂O(g) Is first order in H₂ and second order in NO.Starting with equal concentrations of H₂ and NO,The rate after 50% of the H₂ has reacted is what percent of the initial rate?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
a = k₁k₂...
View Answer

Consider the mechanism NO₂(g) + F₂(g) $\rightarrow$ NO₂F(g) + F(g) K₁ (slow) F(g) + NO₂(g) $\rightarrow$ NO₂F(g) K₂ (fast) Give the molecularity of the first step and any intermediates in the mechanism.

Correct Answer
verified
A

Correct Answer
verified

For the elementary reaction A + 2B $\rightarrow$ products, rate = k[A][B].

Correct Answer
verified

For the reaction cyclobutane(g) $\rightarrow$ 2ethylene(g) At 800 K,A plot of ln[cyclobutane] vs t gives a straight line with a slope of -1.6 s^-¹.Calculate the time needed for the concentration of cyclobutane to fall to 1/16 of its initial value.

Correct Answer
verified

For the reaction Cyclopropane $\rightarrow$ propene A plot of ln[cyclopropane] vs time in seconds gives a straight line with slope -4.1 * 10^-³ s^-¹ at 550^$\omicron$C.What is the rate constant for this reaction?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified