Rates of Reaction: Interactive Quizzes and Learning Resources

Question 1

How does increasing the surface area of a reactant affect the reaction rate?

Accepted Answer

Increases the reaction rate

Answer

Decreases the reaction rate

Answer

Does not change the reaction rate

Question 2

Define an inhibitor and explain how it affects the rate of a reaction.

Accepted Answer

An inhibitor is a substance that increases the activation energy of a reaction, slowing it down.

Answer

An inhibitor is a substance that decreases the activation energy of a reaction, speeding it up.

Answer

An inhibitor is a substance that has no effect on the activation energy or reaction rate.

Answer

An inhibitor is a substance that initially increases the reaction rate but then decreases it over time.

Question 3

Question: How can we use the Arrhenius equation to predict the reaction rate at a different temperature? Outline the steps involved.

Accepted Answer

Solve the Arrhenius equation for the rate constant at the new temperature using the activation energy, gas constant, and temperature values.

Answer

Multiply the rate constant by the activation energy and divide by the temperature.

Answer

Plot the natural logarithm of the rate constant against the inverse of the temperature.

Answer

Divide the activation energy by the temperature and multiply by the rate constant.

Question 4

When the concentration of one reactant in a reaction is doubled while keeping the other reactant's concentration the same, what happens to the reaction rate?

Accepted Answer

The reaction rate doubles.

Answer

The reaction rate quadruples.

Answer

The reaction rate halves.

Answer

The reaction rate stays the same.

Question 5

In a chemical reaction where one reactant is solid, how does increasing the particle size of the solid reactant generally affect the reaction rate?

Accepted Answer

Decreases the reaction rate

Answer

Increases the reaction rate

Answer

Does not affect the reaction rate

Question 6

Which of these methods is NOT used to study reaction mechanisms?

Accepted Answer

Titration

Answer

Isotopic labeling

Answer

Kinetic studies

Answer

Computational modeling

Question 7

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

Accepted Answer

Colour of the reaction mixture

Answer

Temperature

Answer

Concentration of reactants

Answer

Surface area of reactants

Question 8

Which of the following is an example of a **heterogeneous** reaction?

Accepted Answer

Reaction of carbon monoxide and oxygen (catalytic converter)

Answer

Reaction of sodium and chlorine

Answer

Reaction of copper sulfate and sodium hydroxide

Answer

Reaction of hydrogen and oxygen

Question 9

What is the effect of a catalyst on the activation energy of a reaction?

Accepted Answer

Decreases activation energy

Answer

Increases activation energy

Answer

No effect on activation energy

Answer

Cannot be determined

Question 10

Which of the following is an example of a unimolecular reaction?

Accepted Answer

Decomposition of ozone

Answer

Reaction of hydrogen and iodine

Answer

Reaction of sodium and water

Answer

Reaction of carbon dioxide and water

Question 11

What is the order of a reaction with respect to a particular reactant if **doubling** the concentration of that reactant quadruples the rate of the reaction?

Accepted Answer

Second

Answer

Zero

Answer

Third

Answer

Fourth

Question 12

Which of the following applications of rates of reaction is used in **food preservation**?

Accepted Answer

Freezing and canning

Answer

Catalytic converters

Answer

Nuclear power stations

Answer

Sterilization of medical equipment

Question 13

The half-life of a radioactive isotope is 10 days. How long will it take for **90%** of the isotope to decay?

Accepted Answer

30 days

Answer

10 days

Answer

20 days

Answer

40 days

Question 14

The rate of a reaction can be measured by

Accepted Answer

Monitoring the change in concentration of reactants or products over time

Answer

Measuring the change in temperature of the reaction

Answer

Measuring the change in volume of the reaction

Answer

Measuring the change in colour of the reaction

Question 15

Which factor does NOT influence the rate of a chemical reaction?

Accepted Answer

Wavelength of light

Answer

Temperature

Answer

Concentration

Answer

Surface area

Question 16

How does increasing the temperature of a reaction affect its rate?

Accepted Answer

Increases the rate

Answer

Decreases the rate

Answer

No effect on the rate

Answer

Reverses the reaction

Question 17

Which graph represents a first-order reaction?

Accepted Answer

Straight line with negative slope

Answer

Curved line with negative slope

Answer

Straight line with positive slope

Answer

Curved line with positive slope

Question 18

What is the activation energy for a reaction if the rate constant doubles for every 10°C increase in temperature?

Accepted Answer

51.2 kJ/mol

Answer

10 kJ/mol

Answer

20 kJ/mol

Answer

102.4 kJ/mol

Question 19

Which factor directly increases the rate of a chemical reaction?

Accepted Answer

Increased temperature

Answer

Decreased surface area of solids

Answer

Decreased concentration of reactants

Answer

Addition of an inhibitor

Question 20

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

Accepted Answer

Electrolytic

Answer

Homogeneous

Answer

Heterogeneous

Answer

Unimolecular

Question 21

What is the main function of a catalyst in a chemical reaction?

Accepted Answer

To decrease the activation energy

Answer

To increase the activation energy

Answer

To reduce the concentration of reactants

Answer

To increase the temperature of the reaction

Question 22

Which of these applications of rates of reaction involves the use of a catalyst?

Accepted Answer

Catalytic converters in cars

Answer

Preserving food

Answer

Nuclear power generation

Answer

Water filtration

Question 23

A reaction has an activation energy of 100 kJ/mol. If the temperature is raised from 25°C to 50°C, by what factor would the reaction rate increase?

Accepted Answer

8

Answer

2

Answer

4

Answer

16

Question 24

Which characteristic is unique to unimolecular reactions?

Accepted Answer

Involve only one reactant molecule

Answer

Have a high activation energy

Answer

Are typically very slow

Answer

Do not require a catalyst

Question 25

Which factor does NOT affect the surface area of a solid reactant?

Accepted Answer

Temperature

Answer

Particle size

Answer

Shape

Answer

Porosity

Question 26

A reaction is found to be zero order with respect to a certain reactant. What does this suggest about the relationship between the reaction rate and the concentration of this reactant?

Accepted Answer

The reaction rate is independent of the concentration of the reactant

Answer

The reaction rate is proportional to the concentration of the reactant

Answer

The reaction rate is inversely proportional to the concentration of the reactant

Answer

The reaction rate is proportional to the square of the concentration of the reactant

Question 27

Which type of reaction mechanism involves the formation of an intermediate complex?

Accepted Answer

Bimolecular reaction

Answer

Elementary reaction

Answer

Heterogeneous reaction

Answer

Unimolecular reaction

Question 28

What is the effect of increasing the temperature of a reaction?

Accepted Answer

Increases the rate of reaction

Answer

Decreases the rate of reaction

Answer

No effect on the rate of reaction

Answer

Changes the activation energy

Question 29

What role does a catalyst play in a reaction?

Accepted Answer

Provides an alternative reaction pathway

Answer

Increases the activation energy

Answer

Decreases the rate of reaction

Answer

Consumes reactants

Question 30

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

Accepted Answer

Volume of reactants

Answer

Temperature

Answer

Concentration

Answer

Surface area

Question 31

Increasing the temperature of a reaction will typically:

Accepted Answer

Increase the number of successful collisions

Answer

Increase the activation energy

Answer

Decrease the rate of reaction

Answer

Have no effect on the reaction rate

Question 32

Which of the following is the definition of 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 produced in a reaction

Answer

A substance that is consumed in a reaction

Question 33

The rate law for a reaction is: Rate = k[A][B]^2. What is the order of the reaction with respect to B?

Accepted Answer

2

Answer

0

Answer

1

Answer

3

Question 34

Which of the following is a heterogeneous reaction?

Accepted Answer

The reaction of a solid and a liquid

Answer

The reaction of two gases

Answer

The reaction of two liquids

Answer

The reaction of two solids

Question 35

What is the activation energy of a reaction?

Accepted Answer

The minimum energy needed for a reaction to occur

Answer

The maximum energy released in a reaction

Answer

The energy of the reactants

Answer

The energy of the products

Question 36

Which of the following will increase the surface area of a reactant?

Accepted Answer

Crushing it into a powder

Answer

Dissolving it in a solvent

Answer

Heating it

Answer

Cooling it

Question 37

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

Accepted Answer

It determines the overall rate of the reaction

Answer

It consumes the most energy

Answer

It is the first step in the mechanism

Answer

It is the last step in the mechanism

Question 38

What is the half-life of a reaction?

Accepted Answer

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

Answer

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

Answer

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

Answer

The time taken for the rate of the reaction to increase by half

Question 39

Increasing the temperature of a reaction will result in:

Accepted Answer

An increase in the rate of reaction

Answer

A decrease in the rate of the reaction

Answer

No change in the rate of the reaction

Answer

The reaction will become irreversible

Question 40

Surface area plays a significant role in the rate of a reaction because it:

Accepted Answer

Provides a larger surface for the reaction to take place

Answer

Increases the number of collisions between reactants

Answer

Decreases the activation energy of the reaction

Answer

Increases the concentration of the reactants

Question 41

A catalyst is a substance that:

Accepted Answer

Provides an alternative pathway for the reaction

Answer

Increases the activation energy of a reaction

Answer

Increases the concentration of the products

Answer

Slows down the rate of the reaction

Question 42

Which of the following is an example of a homogeneous catalyst?

Accepted Answer

Enzymes in biological reactions

Answer

Nickel in the hydrogenation of alkenes

Answer

Hydrochloric acid in the hydrolysis of esters

Answer

Platinum on charcoal in the catalytic converter

Question 43

The rate constant for a reaction represents:

Accepted Answer

The rate of the reaction at a specific temperature

Answer

The initial concentration of the reactants

Answer

The time taken for the reaction to complete

Answer

The activation energy of the reaction

Question 44

The Arrhenius equation relates the rate constant of a reaction to:

Accepted Answer

Temperature and activation energy

Answer

Concentration and temperature

Answer

Surface area and catalyst

Answer

Volume and pressure

Question 45

In a reaction mechanism, the step with the highest activation energy is known as the:

Accepted Answer

Rate-limiting step

Answer

Activation step

Answer

Propagation step

Answer

Termination step

Question 46

Which factor does NOT influence the rate of a chemical reaction?

Accepted Answer

Pressure

Answer

Temperature

Answer

Concentration

Answer

Surface area

Question 47

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

Consumes one of the reactants.

Question 48

How does increasing the surface area of a solid reactant affect its reaction rate?

Accepted Answer

Increases the reaction rate

Answer

Decreases the reaction rate

Answer

Does not affect the reaction rate

Answer

Reverses the reaction

Question 49

Generally, what happens to the reaction rate when the temperature increases?

Accepted Answer

Increases

Answer

Decreases

Answer

Remains the same

Answer

Reverses

Question 50

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

Accepted Answer

Decreases activation energy

Answer

Increases activation energy

Answer

Changes the products

Answer

Slows down the reaction

Question 51

Which of the following is an example of a homogeneous catalyst?

Accepted Answer

Enzymes in biological systems

Answer

Platinum in catalytic converters

Answer

Nickel in hydrogenation

Answer

Iron oxide in the Haber process

Question 52

A reaction's rate law is rate = k[A]^m[B]^n. What is its overall order?

Accepted Answer

m + n

Answer

m - n

Answer

m

Answer

n

Question 53

What is a property of an exothermic reaction?

Accepted Answer

Releases heat

Answer

Absorbs heat

Answer

Negative activation energy

Answer

Slow reaction rate

Question 54

How does increasing the temperature of a reaction affect the rate of reaction?

Accepted Answer

Increases the rate

Answer

Decreases the rate

Answer

Reverses the reaction

Answer

Does not affect the rate

Question 55

Which of the following would increase the surface area of a reactant?

Accepted Answer

Dividing it into smaller pieces

Answer

Stirring it in a solution

Answer

Heating it up

Answer

Cooling it down

Question 56

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

Accepted Answer

It speeds up the reaction without being consumed

Answer

It slows down the reaction

Answer

It changes the products of the reaction

Answer

It starts the reaction

Question 57

What is the rate law for a reaction that is second order with respect to A and first order with respect to B?

Accepted Answer

Rate = k[A]^2[B]

Answer

Rate = k[A]^3[B]^2

Answer

Rate = k[A]^2[B]^3

Answer

Rate = k[A]^3[B]

Question 58

How can the activation energy of a reaction be lowered?

Accepted Answer

Using a catalyst

Answer

Increasing the temperature

Answer

Decreasing the concentration of reactants

Answer

Adding an inhibitor

Question 59

What is the Arrhenius equation used for?

Accepted Answer

Determining the activation energy of a reaction

Answer

Calculating the rate constant of a reaction

Answer

Predicting the products of a reaction

Answer

Measuring the concentration of reactants

Question 60

How do you experimentally determine the order of a reaction with respect to each reactant?

Accepted Answer

Vary the concentration of one reactant while keeping the concentrations of all other reactants constant.

Answer

Measure the rate of the reaction at different temperatures, keeping all other factors constant.

Answer

Add a catalyst to the reaction and observe the change in the reaction rate.

Question 61

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

Accepted Answer

Density

Answer

Surface area of reactants

Answer

Temperature

Answer

Concentration of reactants

Question 62

Which of the following substances acts as a catalyst in a chemical reaction?

Accepted Answer

Enzyme

Answer

Hydrochloric acid

Answer

Distilled water

Answer

Sodium chloride

Question 63

The Arrhenius equation primarily relates the rate constant of a reaction to:

Accepted Answer

Temperature

Answer

Concentration

Answer

Activation energy

Answer

Surface area

Question 64

Which type of reaction mechanism involves the direct collision of two molecules, leading to the creation of a transient intermediate state?

Accepted Answer

Bimolecular

Answer

Homogeneous

Answer

Heterogeneous

Answer

Unimolecular