C6

Question 1

What is the definition of the rate of a chemical reaction?

Answer 1

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

Question 2

What factors affect the rate of a chemical reaction?

Answer 2

Factors include temperature, concentration, surface area, and the presence of a catalyst.

Question 3

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

Answer 3

True

Question 4

Fill in the blank: A catalyst is a substance that __________ the rate of a chemical reaction without being consumed.

Answer 4

increases

Question 5

What is the effect of increasing concentration on the rate of reaction?

Answer 5

Increasing concentration generally increases the rate of reaction.

Question 6

How does surface area affect the rate of reaction?

Answer 6

Increasing the surface area of a reactant increases the rate of reaction.

Question 7

What is the collision theory?

Answer 7

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

Question 8

What is meant by ‘activation energy’?

Answer 8

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

Question 9

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

Answer 9

False

Question 10

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

Answer 10

A catalyst lowers the activation energy needed for a reaction to occur.

Question 11

Define ‘reaction rate’.

Answer 11

Reaction rate is the change in concentration of reactants or products per unit time.

Question 12

What is ‘dynamic equilibrium’?

Answer 12

Dynamic equilibrium is the state in which the rates of the forward and reverse reactions are equal.

Question 13

True or False: At equilibrium, the concentrations of reactants and products are equal.

Answer 13

False

Question 14

What is Le Chatelier’s principle?

Answer 14

Le Chatelier’s principle states that if a system at equilibrium is subjected to a change, the system will adjust to counteract that change.

Question 15

How does pressure affect reactions involving gases at equilibrium?

Answer 15

Increasing pressure shifts the equilibrium position towards the side with fewer moles of gas.

Question 16

Fill in the blank: The rate of a reaction is measured in __________.

Answer 16

moles per liter per second (mol/L/s)

Question 17

What is a ‘rate equation’?

Answer 17

A rate equation expresses the relationship between the rate of a reaction and the concentration of reactants.

Question 18

What does the rate constant (k) represent?

Answer 18

The rate constant (k) is a proportionality factor in the rate equation that is specific to a reaction at a given temperature.

Question 19

True or False: The rate of reaction is always constant.

Answer 19

False

Question 20

What is meant by ‘order of reaction’?

Answer 20

Order of reaction refers to the power to which the concentration of a reactant is raised in the rate equation.

Question 21

Define ‘half-life’ in the context of chemical reactions.

Answer 21

Half-life is the time taken for the concentration of a reactant to decrease to half its initial concentration.

Question 22

What is a ‘zero-order reaction’?

Answer 22

A zero-order reaction is one where the rate of reaction is constant and independent of the concentration of reactants.

Question 23

What is a ‘first-order reaction’?

Answer 23

A first-order reaction is one where the rate is directly proportional to the concentration of one reactant.

Question 24

What is a ‘second-order reaction’?

Answer 24

A second-order reaction is one where the rate is proportional to the square of the concentration of one reactant or to the product of the concentrations of two reactants.

Question 25

True or False: The rate of a reaction can be influenced by the physical state of reactants.

Answer 25

True

Question 26

What is meant by 'reaction mechanism'?

Answer 26

A reaction mechanism is the step-by-step sequence of elementary reactions by which overall chemical change occurs.

Question 27

List the three types of reactions that can be identified by their rate.

Answer 27

The three types are zero-order, first-order, and second-order reactions.

Question 28

What does a catalyst do to the activation energy of a reaction?

Answer 28

A catalyst lowers the activation energy of a reaction.

Question 29

Fill in the blank: The rate of reaction can be increased by increasing the __________ of reactants.

Answer 29

temperature

Question 30

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

Answer 30

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

Question 31

True or False: The concentration of reactants decreases as the reaction progresses.

Answer 31

True

Question 32

What happens to the rate of reaction as reactants are consumed?

Answer 32

The rate of reaction generally decreases as reactants are consumed.

Question 33

What is the significance of the Arrhenius equation?

Answer 33

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

Question 34

What does an increase in temperature do to the kinetic energy of particles?

Answer 34

An increase in temperature increases the kinetic energy of particles.

Question 35

Define 'exothermic reaction'.

Answer 35

An exothermic reaction is a reaction that releases energy, usually in the form of heat.

Question 36

Define 'endothermic reaction'.

Answer 36

An endothermic reaction is a reaction that absorbs energy from its surroundings.

Question 37

What is 'enthalpy change'?

Answer 37

Enthalpy change is the heat change at constant pressure during a reaction.

Question 38

What is the unit of enthalpy change?

Answer 38

The unit of enthalpy change is kilojoules per mole (kJ/mol).

Question 39

True or False: The rate of a reaction is directly proportional to the surface area of solid reactants.

Answer 39

True