3.2.2 - Reaction Rates

Question 1

What is the definition of reaction rate?

Answer 1

The change in concentration of reactants or products per unit time.

Question 2

True or False: Reaction rates can only be increased by raising the temperature.

Answer 2

False

Question 3

Fill in the blank: The rate of a reaction typically ____ as the concentration of reactants decreases.

Answer 3

decreases

Question 4

What effect does increasing the surface area of a solid reactant have on the reaction rate?

Answer 4

It increases the reaction rate.

Question 5

Which of the following factors does NOT affect reaction rate? A) Concentration B) Temperature C) Color D) Pressure

Answer 5

C) Color

Question 6

What is the role of a catalyst in a chemical reaction?

Answer 6

A catalyst speeds up the reaction without being consumed in the process.

Question 7

What is the unit of reaction rate?

Answer 7

mol dm^-3 s^-1

Question 8

True or False: Doubling the concentration of reactants will always double the reaction rate.

Answer 8

False

Question 9

What does the term ‘order of reaction’ refer to?

Answer 9

The power to which the concentration of a reactant is raised in the rate equation.

Question 10

In a first-order reaction, how does the rate change with respect to concentration?

Answer 10

The rate is directly proportional to the concentration.

Question 11

What effect does temperature have on reaction rates?

Answer 11

Increasing temperature generally increases reaction rates.

Question 12

Fill in the blank: The Arrhenius equation relates the rate constant to ____ and activation energy.

Answer 12

temperature

Question 13

What is activation energy?

Answer 13

The minimum energy required for a reaction to occur.

Question 14

True or False: A higher activation energy results in a faster reaction rate.

Answer 14

False

Question 15

What is a rate constant?

Answer 15

A proportionality constant in the rate law that is specific to a given reaction at a certain temperature.

Question 16

What is the effect of increasing pressure on the rate of reaction for gases?

Answer 16

Increasing pressure increases the reaction rate.

Question 17

Which of the following will increase the rate of a gaseous reaction? A) Decreasing volume B) Increasing volume C) Decreasing temperature D) Increasing concentration

Answer 17

D) Increasing concentration

Question 18

What type of graph is typically used to determine reaction order from experimental data?

Answer 18

A concentration vs. time graph.

Question 19

Fill in the blank: The rate of a zero-order reaction is ____ of the concentration of reactants.

Answer 19

independent

Question 20

What is the significance of the rate-determining step in a reaction mechanism?

Answer 20

It is the slowest step that determines the overall reaction rate.

Question 21

True or False: A catalyst changes the activation energy of a reaction.

Answer 21

True

Question 22

What is the term for the study of how fast reactions occur?

Answer 22

Kinetics

Question 23

What does a reaction profile diagram illustrate?

Answer 23

The energy changes during the course of a reaction.

Question 24

Fill in the blank: In a second-order reaction, the rate is proportional to the ____ of the concentration.

Answer 24

square

Question 25

What is the effect of adding a catalyst to an equilibrium reaction?

Answer 25

It speeds up the rate of both the forward and reverse reactions equally.