Question 1

Which of the following best explains why increasing the concentration of reactants generally increases the rate of a chemical reaction according to collision theory?

Accepted Answer

It increases the frequency of collisions between reactant particles.

Question 2

A student is investigating the reaction between zinc and hydrochloric acid. Which change would most effectively increase the rate of reaction?

Accepted Answer

Crushing the zinc into a fine powder.

Question 3

Which of the following equations correctly represents the relationship between reaction rate and concentration for a first-order reaction?

Accepted Answer

$$	ext{rate} = k[	ext{A}]$$

Question 4

Why does increasing the pressure of a gaseous reactant increase the rate of reaction?

Accepted Answer

It increases the number of particles per unit volume, leading to more frequent collisions.

Question 5

Which statement best describes the role of a catalyst in a chemical reaction?

Accepted Answer

A catalyst provides an alternative pathway with lower activation energy.

Question 6

In the context of collision theory, which factor is most directly responsible for the increased rate of reaction when temperature is raised?

Accepted Answer

More particles have energy greater than the activation energy.

Question 7

A powdered catalyst is used in a reaction instead of a solid block. What is the main reason for the increased reaction rate?

Accepted Answer

The powdered catalyst has a greater surface area for collisions.

Question 8

Which of the following changes will NOT increase the rate of a reaction between a solid and a liquid?

Accepted Answer

Decreasing the surface area of the solid.

Question 9

A reaction is carried out in a sealed container. Which of the following will increase the rate of reaction for a gas-phase reaction?

Accepted Answer

Decreasing the volume of the container.

Question 10

Which of the following best describes the effect of temperature on the Maxwell-Boltzmann distribution of molecular energies?

Accepted Answer

Increasing temperature spreads out the distribution and increases the number of particles with energy greater than the activation energy.

Question 11

A hospital sterilizes its equipment using hydrogen peroxide vapor. Which factor would most effectively increase the rate of sterilization?

Accepted Answer

Increasing the temperature of the sterilization chamber.

Question 12

Which of the following is a correct statement about the effect of subdividing a solid reactant in a chemical reaction?

Accepted Answer

Subdividing a solid increases its surface area and increases the frequency of collisions.

Question 13

In a reaction between hydrochloric acid and zinc, which sample will react fastest?

Accepted Answer

Powdered zinc.

Question 14

Which of the following is the best explanation for why a catalyst is not consumed in a chemical reaction?

Accepted Answer

It provides an alternative pathway but is regenerated at the end of the reaction.

Question 15

A chemical plant wants to maximize the rate of a gas-phase reaction. Which combination of changes would be most effective?

Accepted Answer

Increase pressure and temperature.

Question 16

Which of the following is NOT a factor that affects the rate of a chemical reaction?

Accepted Answer

Color of the reactants.

Question 17

A reaction requires a minimum energy for particles to react. What is this energy called?

Accepted Answer

Activation energy.

Question 18

Which of the following scenarios best illustrates the effect of increasing surface area on reaction rate in a real-world context?

Accepted Answer

A sugar cube dissolves slower than granulated sugar in water.

Question 19

Which of the following changes would increase the frequency of successful collisions in a reaction mixture?

Accepted Answer

Increasing the temperature.

Question 20

A pharmaceutical company wants to speed up a reaction to produce a drug. Which of the following strategies would be least effective?

Accepted Answer

Decreasing the temperature.

Factors Affecting Reaction Rate in Organic Chemistry

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