Q: For the reaction $$2N_2O_5(g) \rightarrow 4NO_2(g) + O_2$(g)$$, which of the following is the correct rate expression in terms of the disappearance of $$N_2O_5$$?

$$\text{Rate} = -\frac{1}{2} \frac{d[N_2O_5]}{dt}$$

Q: Given the reaction $$I_2(g) + 3O_2(g$$) \rightarrow 2CO_2(g) + 2H_2O(l)$$, which of the following is the correct rate expression?

$$\text{Rate} = -\frac{d[I_2$]}{dt} = -\frac{1}{3} \frac{d[O_2$]}{dt} = \frac{1}{2} \frac{d[CO_2$]}{dt} = \frac{1}{2} \frac{d[H_2O]}{dt}$$

Question 1

Which of the following best describes the primary focus of chemical kinetics?

Accepted Answer

The study of the rates at which chemical reactions occur.

Question 2

For the reaction $$2N_2O_5(g) \rightarrow 4NO_2(g) + O_2$(g)$$, which of the following is the correct rate expression in terms of the disappearance of $$N_2O_5$$?

Accepted Answer

$$	ext{Rate} = -\frac{1}{2} \frac{d[N_2O_5]}{dt}$$

Question 3

Given the reaction $$I_2(g) + 3O_2(g$$) \rightarrow 2CO_2(g) + 2H_2O(l)$$, which of the following is the correct rate expression?

Accepted Answer

$$	ext{Rate} = -\frac{d[I_2$]}{dt} = -\frac{1}{3} \frac{d[O_2$]}{dt} = \frac{1}{2} \frac{d[CO_2$]}{dt} = \frac{1}{2} \frac{d[H_2O]}{dt}$$

Question 4

Which factor does NOT directly affect the rate of a chemical reaction?

Accepted Answer

Color of the reactants

Question 5

A reaction has the rate law $$	ext{Rate} = k[A][B]^2. If $$the concentration of $$B is $$doubled while $$A$$ remains constant, by what factor does the rate increase?

Accepted Answer

4

Question 6

Which statement about the rate constant $$k is $$TRUE?

Accepted Answer

It is affected by the presence of a catalyst.

Question 7

Using the method of initial rates, a reaction is found to be first order in $$A$$ and second order in $$B. $$Which is the correct rate law?

Accepted Answer

$$	ext{Rate} = k[A][B]^2$$

Question 8

For the reaction $$A ightarrow B$$, the concentration of $$A$$ decreases from 0.065 M to 0.051 M in 10 minutes. What is the average rate of disappearance of $$A in$$ $$	ext{mol dm}^{-3} 	ext{min}^{-1}$$?

Accepted Answer

$$1.4 	imes 10$$^{-3}$$

Question 9

According to collision theory, which of the following is NOT necessary for a successful reaction between two molecules?

Accepted Answer

High molecular mass

Question 10

Which of the following best describes activation energy ($$E_a$$)?

Accepted Answer

The minimum energy required for a reaction to occur.

Question 11

The Arrhenius equation is given by $$k = Ae$$^{-E_a/RT}$$. What does the term A$ represent?

Accepted Answer

Pre-exponential factor or frequency factor

Question 12

A plot of $$\ln k$$ versus $$1/T$$ for a reaction yields a straight line. What is the slope of this line?

Accepted Answer

$$-E_a/R$$

Question 13

Which of the following is an example of a bimolecular elementary reaction?

Accepted Answer

$$NO(g) + NO_3$(g) \rightarrow 2NO_2(g)$$

Question 14

Which statement about reaction mechanisms is TRUE?

Accepted Answer

Elementary steps in a mechanism have rate laws that can be written directly from their molecularity.

Question 15

In a multi-step reaction mechanism, what is the rate-determining step?

Accepted Answer

The slowest elementary step

Question 16

Which of the following will increase the rate constant $$k$$ for a reaction according to the Arrhenius equation?

Accepted Answer

Increasing the temperature

Question 17

A reaction has the rate law $$	ext{Rate} = k[A]^2. If $$the concentration of $$A is $$tripled, by what factor does the rate increase?

Accepted Answer

9

Question 18

Which of the following statements about catalysts is FALSE?

Accepted Answer

Catalysts are consumed during the reaction.

Question 19

Which of the following is NOT a reason for studying chemical kinetics?

Accepted Answer

To determine the color of the products.

Question 20

In the context of collision theory, which change will most effectively increase the rate of a gaseous reaction in a closed container?

Accepted Answer

Increasing the concentration of reactants

Chemical Kinetics: Principles, Rate Laws, and Reaction Mechanisms

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