Rates of reaction

Question 1

What is the definition of the rate of reaction?

Answer 1

The rate of reaction is the speed at which reactants are converted into products in a chemical reaction.

Question 2

True or False: Increasing the concentration of reactants generally increases the rate of reaction.

Answer 2

True

Question 3

What effect does temperature have on the rate of reaction?

Answer 3

Increasing the temperature typically increases the rate of reaction.

Question 4

Fill in the blank: The presence of a __________ can increase the rate of a chemical reaction without being consumed.

Answer 4

catalyst

Question 5

What is the collision theory?

Answer 5

Collision theory states that for a reaction to occur, reactant particles must collide with sufficient energy and proper orientation.

Question 6

Which factor does NOT affect the rate of reaction?

Answer 6

The color of the reactants

Question 7

True or False: Lowering the pressure of a gas reaction decreases the rate of reaction.

Answer 7

True

Question 8

What is the effect of surface area on the rate of reaction?

Answer 8

Increasing the surface area of solid reactants increases the rate of reaction.

Question 9

What is activation energy?

Answer 9

Activation energy is the minimum energy required for a reaction to occur.

Question 10

Multiple Choice: Which of the following increases the rate of a reaction? A) Decrease temperature B) Increase concentration C) Decrease surface area

Answer 10

B) Increase concentration

Question 11

What role do catalysts play in chemical reactions?

Answer 11

Catalysts speed up chemical reactions by lowering the activation energy.

Question 12

Fill in the blank: The rate of reaction can be measured by the change in __________ over time.

Answer 12

concentration

Question 13

What is the relationship between reaction rate and concentration of reactants?

Answer 13

Generally, an increase in reactant concentration leads to an increase in reaction rate.

Question 14

True or False: All reactions occur at the same rate regardless of conditions.

Answer 14

False

Question 15

What happens to the rate of reaction as equilibrium is approached?

Answer 15

The rate of reaction decreases as equilibrium is approached.

Question 16

Multiple Choice: Which of the following factors does NOT influence the rate of a reaction? A) Temperature B) Concentration C) Time of day

Answer 16

C) Time of day

Question 17

What is meant by ‘rate law’?

Answer 17

Rate law is an equation that relates the rate of a reaction to the concentration of reactants.

Question 18

Fill in the blank: The __________ is the measure of how fast products are formed or reactants are consumed.

Answer 18

rate of reaction

Question 19

What is the effect of light on certain chemical reactions?

Answer 19

Light can increase the rate of photochemical reactions.

Question 20

True or False: The rate of reaction is independent of the nature of the reactants.

Answer 20

False

Question 21

What is the effect of increasing pressure on gaseous reactions?

Answer 21

Increasing pressure generally increases the rate of reaction by decreasing volume and increasing concentration.

Question 22

Multiple Choice: Which of the following increases the rate of a reaction? A) Decreasing temperature B) Increasing surface area C) Reducing catalyst concentration

Answer 22

B) Increasing surface area

Question 23

What are intermediates in a reaction mechanism?

Answer 23

Intermediates are species that are formed during the reaction process but are not present in the final products.

Question 24

Fill in the blank: A __________ reaction is one that occurs quickly, often releasing energy.

Answer 24

fast

Question 25

What is the effect of a catalyst on the equilibrium position of a reaction?

Answer 25

A catalyst does not affect the equilibrium position; it only speeds up the rate at which equilibrium is reached.

Question 26

True or False: The addition of a catalyst changes the overall energy change of a reaction.

Answer 26

False

Question 27

What is the term for the maximum rate of reaction that can be achieved under certain conditions?

Answer 27

Maximum reaction rate

Question 28

Multiple Choice: Which reaction would be expected to have a higher rate? A) A reaction with a high activation energy B) A reaction with a low activation energy

Answer 28

B) A reaction with a low activation energy

Question 29

What does the term 'reaction mechanism' refer to?

Answer 29

Reaction mechanism refers to the step-by-step sequence of elementary reactions that lead to the overall chemical change.

Question 30

Fill in the blank: The __________ theory explains how temperature affects the energy of particles.

Answer 30

kinetic molecular

Question 31

What is the order of a reaction?

Answer 31

The order of a reaction is the power to which the concentration of a reactant is raised in the rate law.

Question 32

True or False: An increase in temperature decreases the kinetic energy of particles.

Answer 32

False

Question 33

What is meant by 'rate constant'?

Answer 33

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

Question 34

Multiple Choice: Which factor is most likely to increase the rate of reaction in a solid? A) Decreasing surface area B) Increasing temperature C) Decreasing concentration

Answer 34

B) Increasing temperature

Question 35

What is the significance of the Arrhenius equation?

Answer 35

The Arrhenius equation relates the rate constant of a reaction to temperature and activation energy.

Question 36

Fill in the blank: The __________ of a reaction can be affected by the physical state of the reactants.

Answer 36

rate

Question 37

True or False: Reactions with higher concentrations of reactants typically occur more slowly.

Answer 37

False

Question 38

What is the effect of stirring on the rate of reaction in a mixture?

Answer 38

Stirring can increase the rate of reaction by promoting contact between reactants.

Question 39

Multiple Choice: Which of the following is a factor that affects the rate of reaction? A) Color of reactants B) Concentration C) Size of the container

Answer 39

B) Concentration

Question 40

What does a reaction profile graph illustrate?

Answer 40

A reaction profile graph illustrates the energy changes during a reaction, including activation energy and overall energy change.

Question 41

Fill in the blank: An __________ reaction releases energy to the surroundings.

Answer 41

exothermic

Question 42

What is the role of temperature in collision theory?

Answer 42

Higher temperatures increase the energy and frequency of collisions between particles.

Question 43

True or False: A slower reaction means that the activation energy is high.

Answer 43

True

Question 44

What is the effect of using powdered solid reactants compared to larger chunks?

Answer 44

Powdered solids have a larger surface area, leading to a faster reaction rate.