Kinetics: Master Reaction Rates and Factors in Chemistry

Question 1

Which of the following factors does NOT affect the rate of a chemical reaction?

Accepted Answer

Volume of the reaction vessel

Answer

Temperature

Answer

Concentration of reactants

Answer

Presence of a catalyst

Question 2

Which of the following factors does **NOT** affect the rate of a chemical reaction?

Accepted Answer

Volume of the reaction vessel

Answer

Concentration of reactants

Answer

Temperature

Answer

Activation energy

Question 3

The activation energy of a reaction is the minimum amount of energy required to

Accepted Answer

Reach the transition state

Answer

Break all bonds in the reactants

Answer

Form all bonds in the products

Answer

Lower the potential energy of the reactants

Question 4

Which of the following is a catalyst?

Accepted Answer

A substance that speeds up a reaction without being consumed

Answer

A substance that slows down a reaction

Answer

A substance that changes the products of a reaction

Answer

A substance that increases the activation energy of a reaction

Question 5

The rate law for a reaction describes the relationship between the

Accepted Answer

Reaction rate and the concentration of the reactants

Answer

Reaction rate and the temperature

Answer

Reaction rate and the activation energy

Answer

Reaction rate and the volume of the reaction vessel

Question 6

Which of the following is a characteristic of an elementary reaction?

Accepted Answer

It occurs in a single step

Answer

Its rate law is first order with respect to all reactants

Answer

It has a high activation energy

Answer

It is catalyzed by enzymes

Question 7

The half-life of a reaction is the time required for

Accepted Answer

The concentration of reactants to decrease by half

Answer

The concentration of products to increase by half

Answer

The rate of the reaction to decrease by half

Answer

The activation energy of the reaction to decrease by half

Question 8

The order of a reaction with respect to a particular reactant is determined by

Accepted Answer

The exponent of the concentration of the reactant in the rate law

Answer

The stoichiometric coefficient of the reactant in the balanced chemical equation

Answer

The activation energy of the reaction

Answer

The temperature of the reaction

Question 9

How do catalysts primarily enhance the rate of a reaction?

Accepted Answer

By decreasing the activation energy, making it easier for reactants to reach the transition state.

Answer

By increasing the activation energy, making it harder for reactants to reach the transition state.

Answer

By providing a new reaction pathway that bypasses the original high-energy pathway.

Answer

By consuming one of the reactants, reducing the concentration of reactants and slowing down the reaction.

Question 10

What is the relationship between activation energy and reaction rate?

Accepted Answer

Decreasing activation energy increases the reaction rate.

Answer

Increasing activation energy increases the reaction rate.

Answer

Activation energy has no effect on reaction rate.

Answer

Activation energy is inversely proportional to the reaction rate.

Question 11

What is the order of a reaction with respect to a particular reactant?

Accepted Answer

The exponent to which the concentration of the reactant is raised in the rate law expression.

Answer

The coefficient of the reactant in the balanced chemical equation.

Answer

The number of molecules of the reactant that collide in one reaction.

Answer

The time it takes for the concentration of the reactant to decrease by half.

Question 12

Which equation relates the rate constant of a reaction to the temperature?

Accepted Answer

Arrhenius equation

Answer

Half-life equation

Answer

Rate law equation

Answer

Equilibrium constant equation

Question 13

How does a catalyst affect the activation energy of a reaction?

Accepted Answer

It decreases the activation energy, making the reaction occur faster.

Answer

It increases the activation energy, making the reaction occur slower.

Answer

It does not affect the activation energy.

Answer

It reverses the activation energy.

Question 14

What is the half-life of a reaction?

Accepted Answer

The time it takes for the concentration of reactants to decrease by half.

Answer

The time it takes for the concentration of products to increase by half.

Answer

The time it takes for the reaction rate to decrease by half.

Answer

The time it takes for the activation energy to increase by half.

Question 15

Which of the following is NOT a type of elementary reaction?

Accepted Answer

Quadrimolecular

Answer

Unimolecular

Answer

Bimolecular

Answer

Termolecular

Question 16

What is the rate law for a first-order reaction?

Accepted Answer

Rate = k[A]

Answer

Rate = k[A]^2

Answer

Rate = k[A]^3

Answer

Rate = k

Question 17

Which of the following factors does NOT influence the rate of a chemical reaction?

Accepted Answer

Type of reaction mechanism

Answer

Concentration of reactants

Answer

Temperature

Answer

Surface area of reactants

Question 18

Activation energy of a reaction refers to:

Accepted Answer

The minimum energy required for a reaction to occur

Answer

The energy released during a reaction

Answer

The energy difference between reactants and products

Answer

The rate constant of a reaction

Question 19

Which of the following actions would increase the rate of a reaction?

Accepted Answer

Increasing the concentration of reactants

Answer

Decreasing the temperature

Answer

Decreasing the surface area of reactants

Answer

Removing a catalyst

Question 20

The rate law for a reaction is an equation that:

Accepted Answer

Expresses the relationship between the rate of the reaction and the concentrations of the reactants

Answer

Represents a constant value for the rate of the reaction

Answer

Graphically depicts the progress of the reaction

Answer

Lists the products of the reaction

Question 21

A characteristic of a zero-order reaction is that:

Accepted Answer

The rate of the reaction does not depend on the concentration of reactants

Answer

The rate of the reaction increases with increasing concentration of reactants

Answer

The rate of the reaction decreases with increasing concentration of reactants

Answer

The rate of the reaction is proportional to the concentration of reactants

Question 22

A catalyst:

Accepted Answer

Accelerates a reaction without being consumed

Answer

Slows down a reaction without being consumed

Answer

Is a reactant that remains present at the end of a reaction

Answer

Is a product that is formed at the beginning of a reaction

Question 23

The half-life of a reaction is defined as:

Accepted Answer

The time required for the concentration of reactants to decrease by half

Answer

The time required for the concentration of products to increase by half

Answer

The time required for the rate of the reaction to decrease by half

Answer

The time required for the equilibrium constant of the reaction to change by half

Question 24

Which graphical method is commonly used to determine the order of a reaction?

Accepted Answer

Logarithmic method

Answer

Half-life method

Answer

Initial rate method

Answer

Lineweaver-Burk plot

Question 25

Express the rate law for a second-order reaction.

Accepted Answer

-d[A]/dt = k[A]^2

Answer

-d[A]/dt = k[A]

Answer

-d[A]/dt = k[A][B]

Answer

-d[A]/dt = k[A]^3

Question 26

Identify a factor that increases the rate of a chemical reaction.

Accepted Answer

Increased temperature

Answer

Decreased concentration

Answer

Addition of an inhibitor

Answer

Increased activation energy

Question 27

Define a catalyst.

Accepted Answer

A substance that speeds up a reaction without being consumed

Answer

A substance that slows down a reaction

Answer

A substance that is consumed during the reaction

Answer

A substance that does not affect the reaction rate

Question 28

Determine the reaction order with respect to a reactant if doubling its concentration doubles the reaction rate.

Accepted Answer

First order

Answer

Zero order

Answer

Second order

Answer

Third order

Question 29

Describe a characteristic of an endothermic reaction.

Accepted Answer

Absorbs heat from the surroundings

Answer

Releases heat into the surroundings

Answer

Does not exchange heat with the surroundings

Answer

Increases the temperature of the surroundings

Question 30

Calculate the activation energy if the reaction rate constant doubles when the temperature increases from 298 K to 308 K.

Accepted Answer

21.0 kJ/mol

Answer

10.5 kJ/mol

Answer

42.0 kJ/mol

Answer

84.0 kJ/mol

Question 31

Identify an intermediate formed in the following reaction mechanism: CH4 + Cl2 → CH3Cl + HCl

Accepted Answer

CH3+

Answer

CH3OH

Answer

H2O+

Answer

CH3COOH

Question 32

Which of the following factors does **not** affect the rate of a chemical reaction?

Accepted Answer

Mass of the reactants

Answer

Concentration of reactants

Answer

Temperature

Answer

Surface area of reactants

Question 33

Activation energy is best defined as:

Accepted Answer

The minimum amount of energy required for a reaction to occur

Answer

The maximum amount of energy released in a reaction

Answer

The difference in energy between reactants and products

Answer

The rate at which a reaction occurs

Question 34

Which of the following reactions is likely to have the highest activation energy?

Accepted Answer

N2(g) + O2(g) → 2NO(g)

Answer

2NO(g) → N2O2(g)

Answer

2H2(g) + O2(g) → 2H2O(g)

Answer

CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

Question 35

A catalyst is a substance that:

Accepted Answer

Decreases the activation energy of a reaction

Answer

Increases the activation energy of a reaction

Answer

Changes the products of a reaction

Answer

Is consumed in a reaction

Question 36

The rate law for a reaction:

Accepted Answer

Shows the relationship between the reaction rate and reactant concentrations

Answer

Is a constant for a specific reaction

Answer

Graphs the progress of a reaction over time

Answer

Lists the products of a reaction

Question 37

The half-life of a reaction is:

Accepted Answer

The time for reactant concentration to halve

Answer

The time for product concentration to double

Answer

The time for the reaction rate to halve

Answer

The time for the equilibrium constant to reach half its maximum value

Question 38

Which term describes the study of reaction rates and the factors that influence them?

Accepted Answer

Kinetics

Answer

Thermodynamics

Answer

Equilibria

Answer

Electrochemistry

Question 39

The energy barrier that must be overcome for a reaction to occur is known as:

Accepted Answer

Activation energy

Answer

Gibbs free energy

Answer

Reaction energy

Answer

Enthalpy of formation

Question 40

The rate law for a reaction expresses the relationship between the:

Accepted Answer

Rate of reaction and the concentrations of reactants

Answer

Activation energy and the temperature

Answer

Equilibrium constant and the concentrations of products and reactants

Answer

Enthalpy change and the entropy change

Question 41

The order of a reaction with respect to a reactant is:

Accepted Answer

The exponent to which the concentration of the reactant is raised in the rate law

Answer

The coefficient of the reactant in the balanced chemical equation

Answer

The change in concentration of the reactant over time

Answer

The time it takes for the reactant to reach equilibrium

Question 42

The integrated rate law for a first-order reaction is:

Accepted Answer

ln[A]t = -kt + ln[A]0

Answer

1/[A]t = kt + 1/[A]0

Answer

ln(k) = -t/ln[A]0

Answer

[A]t = [A]0ekt

Question 43

Which method is commonly used to determine the order of a reaction?

Accepted Answer

Varying the initial concentrations of the reactants

Answer

Measuring the rate of reaction at different temperatures

Answer

Adding a catalyst to the reaction

Answer

Measuring the equilibrium constant for the reaction

Question 44

The activation energy of a reaction can be determined by:

Accepted Answer

Plotting the ln(k) vs. 1/T

Answer

Plotting the k vs. T

Answer

Plotting the ln(concentration) vs. time

Answer

Measuring the equilibrium constant for the reaction

Question 45

Which of the following factors does not affect the rate of a chemical reaction?

Accepted Answer

Geographic location of the reaction

Answer

Presence of a catalyst

Answer

Concentration of reactants

Answer

Surface area of reactants

Question 46

What is the relationship between activation energy and the rate of a reaction?

Accepted Answer

Higher Ea, slower reaction rate

Answer

Indirect relationship

Answer

No relationship

Answer

Higher Ea, faster reaction rate

Question 47

Which of the following is a common type of catalyst?

Accepted Answer

Enzyme

Answer

Inert gas

Answer

Inhibitor

Question 48

What is the order of a reaction with respect to a particular reactant?

Accepted Answer

Exponent of the concentration term in the rate law expression

Answer

Coefficient of the reactant in the balanced chemical equation

Answer

Number of moles of the reactant used

Question 49

Which of the following is a common application of reaction kinetics?

Accepted Answer

Predicting the effectiveness of a new drug

Answer

Calculating the speed of a car

Answer

Determining the age of Earth

Answer

Measuring the distance to the stars

Question 50

What is the half-life of a reaction?

Accepted Answer

Time required for the concentration of reactants to decrease by half

Answer

Time required for the concentration of products to double

Answer

Time required for the reaction to reach 90% completion

Question 51

Which of the following is a characteristic of a zero-order reaction?

Accepted Answer

Rate is independent of reactant concentration

Answer

Rate has units of concentration per time

Answer

Rate is proportional to the square of the reactant concentration