Question 1

Which of the following best explains why a fine powder reacts faster than a solid chunk of the same substance in a heterogeneous reaction?

Accepted Answer

The powder has a greater surface area, allowing more collisions between reactant particles.

Question 2

A reaction is found to be first order in A and second order in B. Which is the correct rate law for this reaction?

Accepted Answer

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

Question 3

Which of the following statements about catalysts is TRUE?

Accepted Answer

Catalysts lower the activation energy of a reaction, increasing the reaction rate.

Question 4

For the reaction $2	ext{NO}_2 ightarrow 2	ext{NO} + 	ext{O}_2$, the following data are collected: $\ln[	ext{NO}_2]$ vs. time is not linear, but $1/[	ext{NO}_2]$ vs. time is linear. What is the order of the reaction?

Accepted Answer

Second order

Question 5

Which of the following is the correct integrated rate law for a first-order reaction?

Accepted Answer

$\ln\left(\frac{[A]}{[A]_0}\right) = -kt$

Question 6

A reaction has a half-life that does not depend on the initial concentration of the reactant. What is the order of this reaction?

Accepted Answer

First order

Question 7

The Arrhenius equation relates the rate constant $k$ to temperature $T$ and activation energy $E_a$. Which is the correct form of the Arrhenius equation?

Accepted Answer

$k = Ae^{-E_a/RT}$

Question 8

Which of the following best describes the rate-determining step in a reaction mechanism?

Accepted Answer

It is the slowest step in the mechanism and limits the overall reaction rate.

Question 9

For a reaction with the rate law $	ext{Rate} = k[A]$, what is the half-life formula?

Accepted Answer

$t_{1/2} = \frac{0.693}{k}$

Question 10

Which of the following is NOT a requirement for a plausible reaction mechanism?

Accepted Answer

All intermediates must appear in the overall balanced equation.

Question 11

Which of the following statements about the effect of temperature on reaction rate is correct?

Accepted Answer

Increasing temperature increases the rate constant $k$ and the reaction rate.

Question 12

A reaction is zero order in reactant A. Which of the following is true?

Accepted Answer

The rate of the reaction does not depend on the concentration of A.

Question 13

Which of the following best describes a reaction intermediate?

Accepted Answer

A species that is formed in one step of a mechanism and consumed in a later step.

Question 14

Which of the following is a correct statement about the molecularity of an elementary reaction?

Accepted Answer

Bimolecular reactions involve the collision of two reactant molecules.

Question 15

Which of the following is a real-world example of a heterogeneous catalyst?

Accepted Answer

A solid platinum catalyst used in the catalytic converter of a car to convert CO to CO$_2$.

Question 16

Which of the following best explains why increasing the concentration of reactants generally increases the reaction rate?

Accepted Answer

There are more frequent collisions between reactant molecules.

Question 17

Which of the following is the correct integrated rate law for a second-order reaction with respect to A?

Accepted Answer

$\frac{1}{[A]} = \frac{1}{[A]_0} + kt$

Question 18

Which of the following is true about the half-life of a second-order reaction?

Accepted Answer

It depends on the initial concentration of the reactant.

Question 19

Which of the following is a correct statement about enzymes?

Accepted Answer

Enzymes are biological catalysts that have specific active sites for substrates.

Chapter 14: Chemical Kinetics – Mini-Textbook Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards