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KS4 Chemistry - Rates of Reaction

Total questions: 20

Worksheet time: 11mins

Name
Class
Date
1.

How does a catalyst work in speeding up a reaction?

a)

By lowering the activation energy or reaction

b)

by giving them more energy

c)

by making them more available

2.
The following graph shows two different reaction pathways for the same overall reaction at the same temperature. Which pathway is slower and why?
a)
Red, because the activation energy is larger
b)
Blue, because the activation energy is lower
c)
both reaction progress at the same rate
3.
What does NOT happen when the temperature is increased?
a)
Particles collide more often
b)
Particles collide with more energy
c)
Particles move faster
d)
More particles collide in the correct orientation
4.
In an exothermic reaction, heat is ...
a)
taken in
b)
given out
5.

Why does a higher concentration increase the rate of reaction?

a)

it increases the amount of reactants

b)

it lowers the activation energy

c)

it increases the energy of particle collisions

d)

it increases the frequency of particle collisions

6.

Why does a higher temperature increase the rate of a reaction?

a)

it increases both the frequency and energy of particle collisions

b)

it only increases the frequency of particle collisions

c)

it only increases the energy of particle collisions

d)

it reduces the activation energy of the reaction

7.
Why don't all collisions between particles cause a reaction?
a)
the particles also need to collide with a catalyst
b)
not all the particles collide with enough energy
c)
not all the particles collide at a high enough temperature
d)
the particles need to collide with each other twice
8.
What is the rate of reaction?
a)
How fast a reaction is 
b)
How big a reaction is
c)
How loud a reaction is
d)
How much gas a reaction produces
9.

The minimum amount of energy needed for colliding particles to react is called

a)

Chemical Energy

b)

Kinetic Energy

c)

Activation Energy

d)

Potential Energy

10.
Which of the following increase the reaction rate?
a)
less surface area
b)
lower temperature
c)
an inhibitor
d)
increased concentration
11.
Why does a higher temperature increase the rate of a reaction?
a)
it increases both the frequency and energy of particle collisions
b)
it only increases the frequency of particle collisions
c)
it only increases the energy of particle collisions
d)
it reduces the activation energy of the reaction
12.

How could we make this reaction happen more quickly?

a)

Decrease the concentration of the acid

b)

crush the chalk to increase the surface area

c)

Put the test tube in an ice bath

13.

When surface area is decreased the rate of reaction...

a)

Decreases, because there are LESS possible sites for correct collisions

b)

Increases, because there are LESS possible sites for correct collisions

c)

Decreases, because there are MORE possible sites for correct collisions

d)

Increases, because there are MORE possible sites for correct collisions

14.

Why does a higher concentration increase the rate of reaction?

a)

it increases the amount of reactants

b)

it lowers the activation energy

c)

it increases the energy of reactant particles

d)

it increases the frequency of collision

15.

Increasing pressure causes the reacting particles

a)

to bond together

b)

to repel from each other

c)

gain more kinetic energy

d)

to move closer together

16.

What is a catalyst?

a)

A very fast moggie

b)

A substance that increases the rate of a reaction and is used up

c)

A substance that increases the rate of a reaction but is not used up

d)

A substance that decreases the rate of a reaction and is not used up

17.

On the diagram, which letter represents the activation energy for the reaction?

a)

A

b)

B

c)

C

18.

Which of the two reaction profiles shows the catalysed reaction?

a)

A

b)

B

19.

Which of the curves indicates the fastest reaction?

a)

A

b)

B

c)

C

20.

Which of the curves indicates the slowest reaction?

a)

A

b)

B

c)

C