Question 1

The decomposition of formic acid follows first-order kinetics. HCO2H(g) → CO2(g) + H2(g) 
The half-life for the reaction at 550 °C is 24 seconds.How many seconds does it take for the formic acid concentration to decrease by 87.5%?

Accepted Answer

A)   24 s
B)   36 s
C)   48 s
D)   72 s
E)   96 sF) None of the above
G) B) and D)

Question 2

The reaction,A + 2B → B2 + A,proceeds by the following mechanism: (A is a catalyst.)  A + B → AB
(slow) 
AB + B → B2 + A
(fast) 
What is the rate law expression for this reaction?

Accepted Answer

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

Question 3

Radioactive isotopes decay by ________-order kinetics.

Accepted Answer

The answer of Radioactive isotopes decay by ________-order kinetics....

Question 4

Draw the reaction coordinate diagram for an exothermic reaction involving three mechanistic steps.

Accepted Answer

The answer of Draw the reaction coordinate diagram for an...

Question 5

For the reaction A → B + C,which of the following equations corresponds to the integrated expression for a second-order decomposition reaction?

Accepted Answer

A)   
B)   
C)   
D)   
E)   F) All of the above
G) A) and D)

Question 6

The decomposition of phosphine,PH3,follows first-order kinetics. 4 PH3(g) → P4(g) + 6 H2(g) 
The half-life for the reaction at 550 °C is 81.3 seconds.What percentage of phosphine remains after 195 seconds?

Accepted Answer

A)   2.2%
B)   9.8%
C)   19%
D)   42%
E)   58%F) A) and E)
G) A) and D)

Question 7

Molecules must overcome a barrier called the activation energy if they are to react.The highest energy point reached during the progress of a reaction is called the ____.

Accepted Answer

A)   rate determining step
B)   transition state
C)   half-life
D)   elementary step
E)   intermediate stateF) A) and E)
G) B) and E)

Question 8

Which of the following statements is correct for the first-order reaction: A → 2B?

Accepted Answer

A)   The concentration of A decreases linearly with respect to time.
B)   The concentration of A is constant with respect to time.
C)   The natural logarithm of the concentration of A decreases linearly with respect to time.
D)   The rate of reaction is constant with respect to time.
E)   The rate constant,k,of the reaction decreases linearly with respect to time.F) D) and E)
G) None of the above

Question 9

For the reaction provided,the rate of disappearance of I-(aq) at a particular time and concentration is 2.4 × 10-3 mol/L·s. IO3-(aq) + 5I-(aq) + 6H+(aq) → 3I2(aq) + 3H2O(l) 
What is the relative rate of appearance of I2(aq) ?

Accepted Answer

A)   4.0 × 10-3 mol/L·s
B)   7 × 10-3 mol/L·s..
C)   -1 × 10-3 mol/L·s
D)   1 × 10-3 mol/L·s
E)   7 × 10-3 mol/L·sF) C) and E)
G) A) and B)

Question 10

The rate constant of a first-order decomposition reaction is 0.0147 s-1.If the initial concentration of reactant is 0.178 M,what is the concentration of reactant after 30.0 seconds?

Accepted Answer

A)   8.72 × 105 M
B)   0.0645 M
C)   0.115 M
D)   0.0785 M
E)   0.643 MF) A) and E)
G) B) and E)

Question 11

The rate constant for a reaction at 40.0°C is exactly 6 times that at 20.0°C.Calculate the Arrhenius energy of activation for the reaction.(R = 8.314 J/K⋅mol)

Accepted Answer

A)   6.00 kJ/mol
B)   8.22 kJ/mol
C)   68.3 kJ/mol
D)   14.9 kJ/mol
E)   none of theseF) A) and D)
G) A) and C)

Question 12

The _____ of an elementary step is defined as the number of reactant molecules that come together in a reaction.

Accepted Answer

The answer of The _____ of an elementary step is...

Question 13

Consider the exothermic combustion of coal.Which of the following could increase the rate of reaction?

Accepted Answer

A)   Using smaller pieces of coal
B)   Increasing the concentration of oxygen
C)   Lowering the temperature
D)   Both a and b are correct.
E)   None of theseF) A) and E)
G) B) and E)

Question 14

In a reaction coordinate diagram,reacting molecules are most unstable ______.

Accepted Answer

A)   at their initial position
B)   when they are about to collide
C)   right after they collide
D)   at the transition stateE) A) and B)
F) B) and D)

Question 15

A second-order reaction starts with an initial concentration of 0.100 mol/L of the reactant.If the rate constant is 1.4 × 10-2 L/mol·s,what is the time required to decrease the initial concentration to 0.050 mol/L? 2A → B
Rate = k[A]2

Accepted Answer

A)   710 s
B)   1100 s
C)   49.5 s
D)   3.57 s
E)   2100 sF) B) and D)
G) None of the above

Question 16

For the overall reaction A + 2B → C,which of the following mechanisms yields the correct overall chemical equation and is consistent with the rate equation below? Rate = k[A][B]

Accepted Answer

A)   A + B  I (fast) I + A → C (slow) 
B)   A + B → I (slow) I + B → C (fast) 
C)   2B → I (slow) A + I → C (fast) 
D)   2B  I (fast) I + A → C (slow) 
E)   A + 2B  I (fast) I + B → C + B (slow) F) A) and C)
G) C) and D)

Question 17

The Arrhenius equation,  expresses the dependence of the rate constant on the reaction temperature.The slope of a plot of ln(k) versus 1/T is equal to

Accepted Answer

A)   
B)   
C)   
D)   
E)   F) A) and E)
G) B) and E)

Question 18

A catalyst ____.

Accepted Answer

A)   is used up in a chemical reaction
B)   changes the potential energy change of the reaction
C)   is always a solid
D)   does not influence the reaction in any way
E)   changes the activation energy of the reactionF) C) and E)
G) C) and D)

Question 19

Consider the following proposed mechanism.If this mechanism for the overall reaction were correct,and if k1 were much less than k2,then the observed rate law would be 2A 1 were much less than k2,then the observed rate law would be 2A   C + I I + B   C + D A)  rate = k1[A] B)  rate = k2[I][B] C)  rate = k1[A]2 D)  rate = k1[A]2 − k2[C][D] E)  rate = k1k2[A]2[I][B]" class="answers-bank-image d-inline" rel="preload" > C + I
I + B 1 were much less than k2,then the observed rate law would be 2A   C + I I + B   C + D A)  rate = k1[A] B)  rate = k2[I][B] C)  rate = k1[A]2 D)  rate = k1[A]2 − k2[C][D] E)  rate = k1k2[A]2[I][B]" class="answers-bank-image d-inline" rel="preload" > C + D

Accepted Answer

A)   rate = k1[A]
B)   rate = k2[I][B]
C)   rate = k1[A]2
D)   rate = k1[A]2 − k2[C][D]
E)   rate = k1k2[A]2[I][B]F) A) and E)
G) A) and D)

Question 20

Nitrogen dioxide reacts with carbon monoxide to produce nitrogen monoxide and carbon dioxide. NO2(g) + CO(g) → NO(g) + CO2(g) 
A proposed mechanism for this reaction is
2 NO2(g)  2(g) + CO(g) → NO(g) + CO2(g)  A proposed mechanism for this reaction is 2 NO2(g)    NO3(g) + NO(g)  (fast,equilibrium)  NO3(g) + CO(g) → NO2(g) + CO2(g)  (slow)  What is a rate law that is consistent with the proposed mechanism? A)  rate = k[NO2]2[CO] [NO]-1 B)  rate = k[NO2]2[CO] C)  rate = k[NO2][CO] D)  rate = k[NO3][CO] E)  rate = k[NO2]2" class="answers-bank-image d-inline" rel="preload" > NO3(g) + NO(g) 
(fast,equilibrium) 
NO3(g) + CO(g) → NO2(g) + CO2(g) 
(slow) 
What is a rate law that is consistent with the proposed mechanism?

Accepted Answer

A)   rate = k[NO2]2[CO] [NO]-1
B)   rate = k[NO2]2[CO]
C)   rate = k[NO2][CO]
D)   rate = k[NO3][CO]
E)   rate = k[NO2]2F) A) and D)
G) A) and C)

Exam 15: Chemical Kinetics: the Rates of Chemical Reactions

The reaction,A + 2B → B₂ + A,proceeds by the following mechanism: (A is a catalyst.) A + B → AB (slow) AB + B → B₂ + A (fast) What is the rate law expression for this reaction?

Correct Answer
verified

A second-order reaction starts with an initial concentration of 0.100 mol/L of the reactant.If the rate constant is 1.4 × 10^-2 L/mol·s,what is the time required to decrease the initial concentration to 0.050 mol/L? 2A → B Rate = k[A]²

Correct Answer
verified

Draw the reaction coordinate diagram for an exothermic reaction involving three mechanistic steps.

Correct Answer
verified

Consider the exothermic combustion of coal.Which of the following could increase the rate of reaction?

Correct Answer
verified

Consider the following proposed mechanism.If this mechanism for the overall reaction were correct,and if k₁ were much less than k₂,then the observed rate law would be 2A C + I I + B C + D

Correct Answer
verified

The Arrhenius equation, expresses the dependence of the rate constant on the reaction temperature.The slope of a plot of ln(k) versus 1/T is equal to

Correct Answer
verified

In a reaction coordinate diagram,reacting molecules are most unstable ______.

Correct Answer
verified

Which of the following statements is correct for the first-order reaction: A → 2B?

Correct Answer
verified

Molecules must overcome a barrier called the activation energy if they are to react.The highest energy point reached during the progress of a reaction is called the ____.

Correct Answer
verified

For the reaction A → B + C,which of the following equations corresponds to the integrated expression for a second-order decomposition reaction?

Correct Answer
verified

The rate constant of a first-order decomposition reaction is 0.0147 s^-1.If the initial concentration of reactant is 0.178 M,what is the concentration of reactant after 30.0 seconds?

Correct Answer
verified

The rate constant for a reaction at 40.0°C is exactly 6 times that at 20.0°C.Calculate the Arrhenius energy of activation for the reaction.(R = 8.314 J/K⋅mol)

Correct Answer
verified

Radioactive isotopes decay by ________-order kinetics.

Correct Answer
verified

A catalyst ____.

Correct Answer
verified

The decomposition of phosphine,PH₃,follows first-order kinetics. 4 PH₃(g) → P₄(g) + 6 H₂(g) The half-life for the reaction at 550 °C is 81.3 seconds.What percentage of phosphine remains after 195 seconds?

Correct Answer
verified

For the overall reaction A + 2B → C,which of the following mechanisms yields the correct overall chemical equation and is consistent with the rate equation below? Rate = k[A][B]

Correct Answer
verified

For the reaction provided,the rate of disappearance of I^-(aq) at a particular time and concentration is 2.4 × 10^-3 mol/L·s. IO₃^-(aq) + 5I^-(aq) + 6H⁺(aq) → 3I₂(aq) + 3H₂O(l) What is the relative rate of appearance of I₂(aq) ?

Correct Answer
verified

The _____ of an elementary step is defined as the number of reactant molecules that come together in a reaction.

Correct Answer
verified

Correct Answer
verified

The decomposition of formic acid follows first-order kinetics. HCO₂H(g) → CO₂(g) + H₂(g) The half-life for the reaction at 550 °C is 24 seconds.How many seconds does it take for the formic acid concentration to decrease by 87.5%?

Correct Answer
verified

Exam 15: Chemical Kinetics: the Rates of Chemical Reactions

The reaction,A + 2B → B2 + A,proceeds by the following mechanism: (A is a catalyst.) A + B → AB (slow) AB + B → B2 + A (fast) What is the rate law expression for this reaction?

Correct AnswerverifiedShow Answer

A second-order reaction starts with an initial concentration of 0.100 mol/L of the reactant.If the rate constant is 1.4 × 10-2 L/mol·s,what is the time required to decrease the initial concentration to 0.050 mol/L? 2A → B Rate = k[A]2

Correct AnswerverifiedShow Answer

Draw the reaction coordinate diagram for an exothermic reaction involving three mechanistic steps.

Correct AnswerverifiedShow Answer

Consider the exothermic combustion of coal.Which of the following could increase the rate of reaction?

Correct AnswerverifiedShow Answer

Consider the following proposed mechanism.If this mechanism for the overall reaction were correct,and if k1 were much less than k2,then the observed rate law would be 2A C + I I + B C + D

Correct AnswerverifiedShow Answer

The Arrhenius equation, expresses the dependence of the rate constant on the reaction temperature.The slope of a plot of ln(k) versus 1/T is equal to

Correct AnswerverifiedShow Answer

In a reaction coordinate diagram,reacting molecules are most unstable ______.

Correct AnswerverifiedShow Answer

Which of the following statements is correct for the first-order reaction: A → 2B?

Correct AnswerverifiedShow Answer

Molecules must overcome a barrier called the activation energy if they are to react.The highest energy point reached during the progress of a reaction is called the ____.

Correct AnswerverifiedShow Answer

For the reaction A → B + C,which of the following equations corresponds to the integrated expression for a second-order decomposition reaction?

Correct AnswerverifiedShow Answer

The rate constant of a first-order decomposition reaction is 0.0147 s-1.If the initial concentration of reactant is 0.178 M,what is the concentration of reactant after 30.0 seconds?

Correct AnswerverifiedShow Answer

The rate constant for a reaction at 40.0°C is exactly 6 times that at 20.0°C.Calculate the Arrhenius energy of activation for the reaction.(R = 8.314 J/K⋅mol)

Correct AnswerverifiedShow Answer

Radioactive isotopes decay by ________-order kinetics.

Correct AnswerverifiedShow Answer

A catalyst ____.

Correct AnswerverifiedShow Answer

The decomposition of phosphine,PH3,follows first-order kinetics. 4 PH3(g) → P4(g) + 6 H2(g) The half-life for the reaction at 550 °C is 81.3 seconds.What percentage of phosphine remains after 195 seconds?

Correct AnswerverifiedShow Answer

For the overall reaction A + 2B → C,which of the following mechanisms yields the correct overall chemical equation and is consistent with the rate equation below? Rate = k[A][B]

Correct AnswerverifiedShow Answer

For the reaction provided,the rate of disappearance of I-(aq) at a particular time and concentration is 2.4 × 10-3 mol/L·s. IO3-(aq) + 5I-(aq) + 6H+(aq) → 3I2(aq) + 3H2O(l) What is the relative rate of appearance of I2(aq) ?

Correct AnswerverifiedShow Answer

The _____ of an elementary step is defined as the number of reactant molecules that come together in a reaction.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The decomposition of formic acid follows first-order kinetics. HCO2H(g) → CO2(g) + H2(g) The half-life for the reaction at 550 °C is 24 seconds.How many seconds does it take for the formic acid concentration to decrease by 87.5%?

Correct AnswerverifiedShow Answer

The reaction,A + 2B → B₂ + A,proceeds by the following mechanism: (A is a catalyst.) A + B → AB (slow) AB + B → B₂ + A (fast) What is the rate law expression for this reaction?

Correct Answer
verified

A second-order reaction starts with an initial concentration of 0.100 mol/L of the reactant.If the rate constant is 1.4 × 10^-2 L/mol·s,what is the time required to decrease the initial concentration to 0.050 mol/L? 2A → B Rate = k[A]²

Correct Answer
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Correct Answer
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Correct Answer
verified

Consider the following proposed mechanism.If this mechanism for the overall reaction were correct,and if k₁ were much less than k₂,then the observed rate law would be 2A C + I I + B C + D

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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The rate constant of a first-order decomposition reaction is 0.0147 s^-1.If the initial concentration of reactant is 0.178 M,what is the concentration of reactant after 30.0 seconds?

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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The decomposition of phosphine,PH₃,follows first-order kinetics. 4 PH₃(g) → P₄(g) + 6 H₂(g) The half-life for the reaction at 550 °C is 81.3 seconds.What percentage of phosphine remains after 195 seconds?

Correct Answer
verified

Correct Answer
verified

For the reaction provided,the rate of disappearance of I^-(aq) at a particular time and concentration is 2.4 × 10^-3 mol/L·s. IO₃^-(aq) + 5I^-(aq) + 6H⁺(aq) → 3I₂(aq) + 3H₂O(l) What is the relative rate of appearance of I₂(aq) ?

Correct Answer
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Correct Answer
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Correct Answer
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The decomposition of formic acid follows first-order kinetics. HCO₂H(g) → CO₂(g) + H₂(g) The half-life for the reaction at 550 °C is 24 seconds.How many seconds does it take for the formic acid concentration to decrease by 87.5%?

Correct Answer
verified