Question 1

If a reaction is first order with a rate constant of 5.48 × 10-2/s,how long is required for 3/4 of the initial concentration of reactant to be used up?

Accepted Answer

A) 25.3 s 
B) 36.5 s 
C) 6.3 s 
D) 18.2 s 
E) 50.6 s 
A) 25.3 s 
B) 36.5 s 
C) 6.3 s 
D) 18.2 s 
E) 50.6 s

Question 2

The reaction has the rate law Rate = k[A][B]2.Which will cause the rate to increase the most?

Accepted Answer

A) doubling [A] 
B) lowering temperature 
C) tripling [B] 
D) quadrupling [A] 
E) doubling [B] 
A) doubling [A] 
B) lowering temperature 
C) tripling [B] 
D) quadrupling [A] 
E) doubling [B]

Question 3

The first-order reaction,SO2Cl2 → SO2 + Cl2,has a half-life of 8.75 hours at 593 K.How long will it take for the concentration of SO2Cl2 to fall to 16.5% of its initial value?

Accepted Answer

A) 0.143 hr 
B) 2.28 hr 
C) 6.99 hr 
D) 22.7 hr 
A) 0.143 hr 
B) 2.28 hr 
C) 6.99 hr 
D) 22.7 hr

Question 4

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 5

For the reaction: 2 N2O5(g)→ 4 NO2(g)+ O2(g)the rate law is: 
 = k[N2O5]
At 300 K,the half-life is 2.50 × 104 seconds and the activation energy is 103.3 kJ/mol.What is the rate constant at 310 K?

Accepted Answer

A) 2.78 × 10-5 s-1 
B) 7.29 × 10-6 s-1 
C) 7.29 × 10-8 s-1 
D) 3.70 × 10-5 s-1 
E) 1.05 × 10-4 s-1 
A) 2.78 × 10-5 s-1 
B) 7.29 × 10-6 s-1 
C) 7.29 × 10-8 s-1 
D) 3.70 × 10-5 s-1 
E) 1.05 × 10-4 s-1

Question 6

A factor that decreases the activation energy for a reaction:
I.decreases the rate constant
II.increases the rate constant
III.has no effect on the rate constant
IV.increases the product yield
V.might be a catalyst

Accepted Answer

A) I and IV 
B) II and IV 
C) I,IV,and V 
D) IV and III 
E) II and V 
A) I and IV 
B) II and IV 
C) I,IV,and V 
D) IV and III 
E) II and V

Question 7

The elementary reaction   (g)→ 2 NO(g)+   (g) Is second order in  
And the rate constant at 501 K is 7.93 × 10-3     .The reaction half-life at this temperature when   = 0.45 mol L-1 is ________ s.

Accepted Answer

A) 3.6 × 10-3 
B) 0.011 
C) 126 
D) 87 
E) 280 
A) 3.6 × 10-3 
B) 0.011 
C) 126 
D) 87 
E) 280

Question 8

The rate of disappearance of HBr in the gas phase reaction
2 HBr(g)→   (g)+   (g)   
Is 0.301 mol L-1   At 150 °C.The rate of appearance of   Is ________ mol L-1  
.

Accepted Answer

A) 1.66 
B) 0.151 
C) 0.0906 
D) 0.602 
E) 0.549 
A) 1.66 
B) 0.151 
C) 0.0906 
D) 0.602 
E) 0.549

Question 9

For the reaction: 2 N2O5(g)→ 4 NO2(g)+ O2(g)the rate law is: 
 = k[N2O5]
At 300 K,the half-life is 2.50 × 104 seconds and the activation energy is 103.3 kJ/mol.What is the rate constant at 350 K?

Accepted Answer

A) 4.78 s-1 
B) 2.79 × 10-5 s-1 
C) 6.38 × 1016 s-1 
D) 7.47 × 10-8 s-1 
E) 1.03 × 10-2 s-1 
A) 4.78 s-1 
B) 2.79 × 10-5 s-1 
C) 6.38 × 1016 s-1 
D) 7.47 × 10-8 s-1 
E) 1.03 × 10-2 s-1

Question 10

In the first-order,reaction A → products,[A] = 0.400 M initially and 0.250 M after 15.0 min,what is the half-life of the reaction?

Accepted Answer

A) 22.1 min 
B) 63.9 min 
C) 9.62 min 
D) 51.0 min 
E) 15.0 min 
A) 22.1 min 
B) 63.9 min 
C) 9.62 min 
D) 51.0 min 
E) 15.0 min

Question 11

If increasing the concentration of A in a chemical reaction 2 A → B + C causes no increase in the rate of the reaction,then we may say:

Accepted Answer

A) A is a catalyst 
B) the reaction rate is zero order in A 
C) the reaction rate is zero order in [A] 
D) the reaction rate is first order in [A] 
E) A is not involved in the reaction 
A) A is a catalyst 
B) the reaction rate is zero order in A 
C) the reaction rate is zero order in [A] 
D) the reaction rate is first order in [A] 
E) A is not involved in the reaction

Question 12

For the reaction: 2 N2O5(g)→ 4 NO2(g)+ O2(g)at the time when N2O5 is being consumed at a rate of 1.2 × 10-4 M/s,what is the rate at which O2 is being formed?

Accepted Answer

A) 1.2 × 10-4 M/s 
B) 2.4 × 10-4 M/s 
C) 6.0 × 10-5 M/s 
D) 3.0 × 10-5 M/s 
E) 4.8 × 10-4 M/s 
A) 1.2 × 10-4 M/s 
B) 2.4 × 10-4 M/s 
C) 6.0 × 10-5 M/s 
D) 3.0 × 10-5 M/s 
E) 4.8 × 10-4 M/s

Question 13

The combustion of ethylene proceeds by the reaction 
    (g)+ 3   (g)→ 2 C   (g)+   O(g)
When the rate of disappearance of   Is 0.23 mol L-1   ,the rate of disappearance of     Is ________

Accepted Answer

A) 0.15 
B) 0.077 
C) 0.69 
D) 0.35 
E) 0.46 
A) 0.15 
B) 0.077 
C) 0.69 
D) 0.35 
E) 0.46

Question 14

What is the main difference between a Pt catalyst and an enzyme catalyst?

Accepted Answer

A) An enzyme has greater substrate specificity. 
B) The Pt catalyst causes a faster reaction. 
C) The enzyme causes a faster reaction. 
D) A Pt catalyst is always a homogeneous catalyst. 
E) A Pt catalyst is an enzyme. 
A) An enzyme has greater substrate specificity. 
B) The Pt catalyst causes a faster reaction. 
C) The enzyme causes a faster reaction. 
D) A Pt catalyst is always a homogeneous catalyst. 
E) A Pt catalyst is an enzyme.

Question 15

The first-order reaction A → Products has a half-life,t1/2,of 55.0 min at 25 °C and 6.8 min at 100 °C.What is the activation energy for this reaction?

Accepted Answer

A) -25.8 kJ/mol 
B) -38.8 kJ/mol 
C) 347 kJ/mol 
D) 25.8 kJ/mol 
E) 38.8 kJ/mol 
A) -25.8 kJ/mol 
B) -38.8 kJ/mol 
C) 347 kJ/mol 
D) 25.8 kJ/mol 
E) 38.8 kJ/mol

Question 16

The first order reaction A → products has  = 150 s.What percent of the sample remains unreacted after 300 s?

Accepted Answer

A) 25% 
B) 50% 
C) 12.5% 
D) 0.0% 
E) 100% 
A) 25% 
B) 50% 
C) 12.5% 
D) 0.0% 
E) 100%

Question 17

In the first-order,reaction A → products,[A] = 0.400 M initially and 0.250 M after 15.0 min,what is the value of the rate constant,k?

Accepted Answer

A) 3.06 min-1  
B) 0.0136 min-1  
C) 0.470 min-1  
D) 7.05 min-1  
E) 0.0313 min-1  
A) 3.06 min-1  
B) 0.0136 min-1  
C) 0.470 min-1  
D) 7.05 min-1  
E) 0.0313 min-1

Question 18

Data for the reaction A + B → C are given below.What is the correct rate law?

Accepted Answer

A) k [A] [B] 
B) k [A]2 [B] 
C) k [A]2 [B]2  
D) k [B]2 
E) k[A]2  
A) k [A] [B] 
B) k [A]2 [B] 
C) k [A]2 [B]2  
D) k [B]2 
E) k[A]2

Question 19

Which is a plausible mechanism for the following reaction if the rate law is  
2 O3 → 3 O2

Accepted Answer

A) 2 O3 → O2 + O4 (slow) 
O4 → 2 O2 (fast) 
B) 2 O3 → O6 (slow) 
O6 → O4 + O2 (fast)
O4 → 2 O2 (slow) 
C) 2 O3 → O4- + O2+ (slow) 
O4- → O2 + O2- (fast)
O2- + O2+ → 2 O2 (slow) 
D) O3 ⇌ O2 + O∙ (fast) 
O∙ + O3 → 2 O2 (slow) 
E) O3 ⇌ O2+ + O- (fast) 
O- + O3 → O2 + O2- (slow)
O2- + O2+ → 2 O2 (fast) 
A) 2 O3 → O2 + O4 (slow) 
O4 → 2 O2 (fast) 
B) 2 O3 → O6 (slow) 
O6 → O4 + O2 (fast)
O4 → 2 O2 (slow) 
C) 2 O3 → O4- + O2+ (slow) 
O4- → O2 + O2- (fast)
O2- + O2+ → 2 O2 (slow) 
D) O3 ⇌ O2 + O∙ (fast) 
O∙ + O3 → 2 O2 (slow) 
E) O3 ⇌ O2+ + O- (fast) 
O- + O3 → O2 + O2- (slow)
O2- + O2+ → 2 O2 (fast)

Question 20

In the first order reaction A → products,[A] = 0.400 M initially and 0.250 M after 15.0 min,what will [A] be after 175 min?

Accepted Answer

A) 1.67 × 10-3 M 
B) 1.04 × 10-3 M 
C) 3.70 × 10-2 M 
D) 6.024 × 10-3 M 
E) 2.31 × 10-1 M 
A) 1.67 × 10-3 M 
B) 1.04 × 10-3 M 
C) 3.70 × 10-2 M 
D) 6.024 × 10-3 M 
E) 2.31 × 10-1 M

Exam 20: Chemical Kinetics

If a reaction is first order with a rate constant of 5.48 × 10-2/s,how long is required for 3/4 of the initial concentration of reactant to be used up?

The reaction has the rate law Rate = k[A][B]2.Which will cause the rate to increase the most?

The first-order reaction,SO2Cl2 → SO2 + Cl2,has a half-life of 8.75 hours at 593 K.How long will it take for the concentration of SO2Cl2 to fall to 16.5% of its initial value?

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?

For the reaction: 2 N2O5(g)→ 4 NO2(g)+ O2(g)the rate law is: = k[N2O5] At 300 K,the half-life is 2.50 × 104 seconds and the activation energy is 103.3 kJ/mol.What is the rate constant at 310 K?

A factor that decreases the activation energy for a reaction: I.decreases the rate constant II.increases the rate constant III.has no effect on the rate constant IV.increases the product yield V.might be a catalyst

The elementary reaction (g)→ 2 NO(g)+ (g) Is second order in And the rate constant at 501 K is 7.93 × 10-3 .The reaction half-life at this temperature when = 0.45 mol L-1 is ________ s.

The rate of disappearance of HBr in the gas phase reaction 2 HBr(g)→ (g)+ (g) Is 0.301 mol L-1 At 150 °C.The rate of appearance of Is ________ mol L-1 .

For the reaction: 2 N2O5(g)→ 4 NO2(g)+ O2(g)the rate law is: = k[N2O5] At 300 K,the half-life is 2.50 × 104 seconds and the activation energy is 103.3 kJ/mol.What is the rate constant at 350 K?

In the first-order,reaction A → products,[A] = 0.400 M initially and 0.250 M after 15.0 min,what is the half-life of the reaction?

If increasing the concentration of A in a chemical reaction 2 A → B + C causes no increase in the rate of the reaction,then we may say:

For the reaction: 2 N2O5(g)→ 4 NO2(g)+ O2(g)at the time when N2O5 is being consumed at a rate of 1.2 × 10-4 M/s,what is the rate at which O2 is being formed?

The combustion of ethylene proceeds by the reaction (g)+ 3 (g)→ 2 C (g)+ O(g) When the rate of disappearance of Is 0.23 mol L-1 ,the rate of disappearance of Is ________

What is the main difference between a Pt catalyst and an enzyme catalyst?

The first-order reaction A → Products has a half-life,t1/2,of 55.0 min at 25 °C and 6.8 min at 100 °C.What is the activation energy for this reaction?

The first order reaction A → products has = 150 s.What percent of the sample remains unreacted after 300 s?

In the first-order,reaction A → products,[A] = 0.400 M initially and 0.250 M after 15.0 min,what is the value of the rate constant,k?

Data for the reaction A + B → C are given below.What is the correct rate law?

Which is a plausible mechanism for the following reaction if the rate law is 2 O3 → 3 O2

In the first order reaction A → products,[A] = 0.400 M initially and 0.250 M after 15.0 min,what will [A] be after 175 min?

Matter: Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Valence Bond and Molecular Orbital Theories

Intermolecular Forces: Liquids and Solids

Spontaneous Change: Entropy and Gibbs Energy

Solutions and Their Physical Properties

Principles of Chemical Equilibrium

Acids and Bases

Additional Aspects of Acidbase Equilibria

Solubility and Complex-Ion Equilibria

Electrochemistry

Chemistry of the Main-Group Elements I: Groups 1,2,13,and 14

Chemistry of the Main-Group Elements Ii: Groups 18,17,16,15,and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry

Structures of Organic Compounds

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If a reaction is first order with a rate constant of 5.48 × 10^-2/s,how long is required for 3/4 of the initial concentration of reactant to be used up?

The reaction has the rate law Rate = k[A][B]².Which will cause the rate to increase the most?

The first-order reaction,SO₂Cl₂ → SO₂ + Cl₂,has a half-life of 8.75 hours at 593 K.How long will it take for the concentration of SO₂Cl₂ to fall to 16.5% of its initial value?

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?

For the reaction: 2 N₂O₅(g)→ 4 NO₂(g)+ O₂(g)the rate law is: = k[N₂O₅] At 300 K,the half-life is 2.50 × 10⁴ seconds and the activation energy is 103.3 kJ/mol.What is the rate constant at 310 K?

The elementary reaction (g)→ 2 NO(g)+ (g) Is second order in And the rate constant at 501 K is 7.93 × 10^-3 .The reaction half-life at this temperature when = 0.45 mol L^-1 is ________ s.

The rate of disappearance of HBr in the gas phase reaction 2 HBr(g)→ (g)+ (g) Is 0.301 mol L^-1 At 150 °C.The rate of appearance of Is ________ mol L^-1 .

For the reaction: 2 N₂O₅(g)→ 4 NO₂(g)+ O₂(g)the rate law is: = k[N₂O₅] At 300 K,the half-life is 2.50 × 10⁴ seconds and the activation energy is 103.3 kJ/mol.What is the rate constant at 350 K?

For the reaction: 2 N₂O₅(g)→ 4 NO₂(g)+ O₂(g)at the time when N₂O₅ is being consumed at a rate of 1.2 × 10^-4 M/s,what is the rate at which O₂ is being formed?

The combustion of ethylene proceeds by the reaction (g)+ 3 (g)→ 2 C (g)+ O(g) When the rate of disappearance of Is 0.23 mol L^-1 ,the rate of disappearance of Is ________

The first-order reaction A → Products has a half-life,t_1/2,of 55.0 min at 25 °C and 6.8 min at 100 °C.What is the activation energy for this reaction?

Which is a plausible mechanism for the following reaction if the rate law is 2 O₃ → 3 O₂