Essential Chemistry for IGCSE - Rate Of Reaction (Section 2)
1
How does the collision theory explain why increasing the temperature increases the rate of reaction?
Answer
(D)
All of the above.
2
What is the function of a catalyst?
Answer
(B)
To decrease the activation energy of a reaction.
3
What effect does a negative catalyst (inhibitor) have on a reaction?
Answer
(B)
Slows it down.
4
Which of the following will affect the rate of the reaction?
Answer
A
B
C
D
5
A student investigates the reaction of magnesium ribbon with hydrochloric acid to produce hydrogen gas. They increase the concentration of the acid. What would happen?
Answer
(C)
The reaction rate would increase.
6
Which of the following factors would affect the rate of a reaction?
Answer
A
B
C
D
7
Which of the following conditions must be met for a chemical reaction to occur, according to collision theory?
Answer
A
B
8
What is the effect of an inhibitor on the rate of a chemical reaction?
Answer
(B)
It slows down the reaction.
9
Which of the following is the correct relationship between the surface area of a solid reactant and the rate of a reaction?
Answer
(C)
As the surface area increases, the rate of reaction increases.
10
What type of data is generally plotted to determine the rate of a reaction?
Answer
(D)
All of the above.
11
In the context of the collision theory, what does the 'orientation' of a collision refer to?
Answer
(C)
The relative positions of the reacting particles during the collision.
12
What is the role of the 'activation energy' in a chemical reaction?
Answer
(C)
It is the energy needed to start the reaction.
13
What are the units for reaction rate?
Answer
(A)
mol L-1 s-1
14
What is the effect of grinding a solid reactant into a fine powder on the rate of reaction?
Answer
(B)
It increases the rate of reaction.
15
What is the effect on reaction rate when the concentration of reactants is increased?
Answer
(A)
Increases
16
Which statement best describes the collision theory?
Answer
(B)
Reactions occur when reactants collide with enough energy and the proper orientation.
17
What is a key requirement for a chemical reaction to occur, according to collision theory?
Answer
(C)
Reactant molecules must collide with the proper orientation and sufficient energy.
18
How does increasing the pressure of a gaseous reactant typically affect the reaction rate?
Answer
(B)
Increases the reaction rate.
19
What is the role of a catalyst in a chemical reaction?
Answer
(B)
To provide an alternative reaction pathway with a lower activation energy.
20
Which of the following correctly describes the effect of increasing temperature on the rate of reaction?
Answer
(C)
Increases both the collision frequency and the kinetic energy.
21
Which of the following is the correct definition of reaction rate?
Answer
(D)
All of the above.
22
According to collision theory, what must occur for a reaction to take place?
Answer
(C)
Reactant molecules must collide with sufficient energy and the correct orientation.
23
Which of the following will increase the rate of reaction?
Answer
A
C
D
24
What is a common method used to measure the rate of reaction?
Answer
(D)
All of the above
25
Which factor affects the rate of a reaction in a heterogeneous system the most?
Answer
(D)
The surface area of the solid reactant
26
Which of the following statements is correct about reaction rate?
Answer
(D)
Reaction rate is the speed at which reactants change into products.
27
What is meant by the term 'activation energy'?
Answer
(B)
The energy required to start a chemical reaction.
28
How does the presence of a catalyst affect the activation energy?
Answer
(B)
It decreases the activation energy.
29
What does the 'order' of a reaction refer to?
Answer
(B)
The power to which the concentration of a reactant is raised in the rate equation.
30
A reaction has a rate law: rate = k[A]^2. What will happen to the rate if [A] is doubled?
Answer
(B)
The rate will quadruple.
31
Which of the following is a common method for following the progress of a reaction?
Answer
(D)
All of the above
32
In a reaction that produces a gas, what is a common method to measure the rate of reaction?
Answer
(B)
Measuring the volume of gas produced
33
How does a catalyst affect the equilibrium of a reversible reaction?
Answer
(D)
It does not affect the position of the equilibrium.
34
What are the limitations of measuring reaction rates by measuring the pressure change?
Answer
A
B
D
35
Which of the following statements is correct?
Answer
(C)
The rate of a reaction is the measure of how fast reactants are converted to products.
36
What effect does increasing the temperature have on the kinetic energy of reactant molecules?
Answer
(B)
Increases the kinetic energy.
37
If the rate law for a reaction is rate = k[A][B], what is the overall order of the reaction?
Answer
(C)
Second order
38
What happens to the rate of reaction if a catalyst is added to a reaction?
Answer
(A)
It increases the rate.
39
What is the primary function of a catalyst in a chemical reaction?
Answer
(B)
To lower the activation energy and speed up the reaction.
40
If a reaction is zero order, what is the rate of the reaction dependent on?
Answer
(D)
None of the above.
41
How does the presence of a catalyst change the energy profile diagram of a reaction?
Answer
(A)
Lowers the activation energy.
42
In a reaction rate experiment, what is the purpose of a control?
Answer
(B)
To compare the experimental results to a baseline.
43
In a reaction involving a solid and a liquid, which of the following is most likely to increase the reaction rate?
Answer
(C)
Increasing the temperature.
44
Which of the following would NOT increase the rate of reaction?
Answer
(D)
Removing the reactants
45
How does temperature influence the number of effective collisions in a chemical reaction?
Answer
(A)
Increases the number of effective collisions.
46
If the rate of a reaction is first order, what will happen if the concentration of the reactant is halved?
Answer
(B)
The rate of the reaction will halve.
47
What impact does a catalyst have on the activation energy?
Answer
(A)
It decreases the activation energy.
48
What is the relationship between the rate of a reaction and the slope of a graph of product concentration versus time?
Answer
(D)
The rate of the reaction is proportional to the slope.
49
How does increasing the pressure affect the rate of a reaction involving gaseous reactants?
Answer
(A)
Increases the rate.
50
How does increasing the temperature of a reaction affect the kinetic energy of the reactant molecules?
