AQA GCSE Chemistry Higher Tier Paper 1
Exam – Actual Exam Questions with Detailed
Answers | Newest Update 2025/2026
1. How do you measure the By measuring the quantity of a reactant used or the quantity of product
rate of a reaction? formed over time
2. What is the equation Mean rate of reaction = quantity of reactant used/time taken
for calculating the mean
rate of a reaction by
measuring the amount
of reactant used?
3. What is the equation Mean rate of reaction = quantity of product formed/time taken
for calculating the mean
rate of a reaction by
measuring the amount
of product formed?
4. What units can you mea- g/s or cm3/s or mol/s
sure the rate of a reac-
tion in?
5. How do you calculate the By measuring the gradient of a tangent drawn at that speci�c time on
rate of a reaction at a the graph
speci�c time from graph
of the quantity of reac-
tant used or the quantity
of product formed?
6. What are the �ve factors Concentration of reactants in solution, pressure of reacting gases,
that can a ect the rate of surface area of solid reactants, temperature and the presence of a
a reaction? catalyst
7. What theory can we use Collision theory
to explain how various
, factors a ect the rate of
a reaction?
8. What is collision theory? Chemical reactions can occur only when reacting particles collide with
each other and with su cient energy
9. What is the activation The minimum amount of energy that particles must have to react
energy of a reaction?
10. According to collision It increases the frequency of collisions and so increases the rate of
theory why does increas- reaction
ing concentration of re-
actant in solution in-
crease the rate of the re-
action?
11. According to collision It increases the frequency of collisions and so increases the rate of
theory why does increas- reaction
ing the pressure of react-
ing gases increase the
rate of the reaction?
12. According to collision It increases the frequency of collisions and so increases the rate of
theory why does increas- reaction
ing the surface area of
solid reactants in solu-
tion increase the rate of
the reaction?
13. According to collision It increases the frequency of collisions and makes the collision more
theory why does in- energetic and so increases the rate of reaction
creasing temperature in-
, crease the rate of the re-
action?
14. How do you increase the Grind it into a powder that has smaller particle size
surface area of a solid re-
actant?
15. What e ect does in- It doubles it
creasing the tempera-
ture of a reaction by 10°C
have on the rate of a re-
action?
16. What is a catalyst? A chemical that changes the rate of a chemical reaction but is not used
up in the reaction
17. How do catalysts in- By providing a di erent pathway for the reaction that has a lower
crease the rate of a reac- activation energy
tion?
18. How do you know in a It is not included in the chemical equation for the reaction
reaction that a chemical
is used in a reaction is a
catalyst?
19. What is a reversible reac- Where the products of a chemical reaction can react to produce the
tion? original reactants
20. What is the symbol used
in reversible reaction
equations that shows
that the reaction is re-
versible?
, 21. How can you change the By changing the conditions; for example heating or cooling the reac-
direction of a reversible tion
reaction?
22. Describe the energy One direction will be exothermic and the other direction endothermic
changes in a reversible
reaction
23. When is equilibrium in When the rate of the forward and reverse reactions occur at exactly the
a reversible reaction same rate
achieved in apparatus
which prevents the es-
cape of reactants and
products?
24. What a ects the rela- The conditions
tive amount of all the
reactants and products
at equilibrium in a re-
versible reaction?
25. What happens to an The system responds to counteract the change
equilibrium if any of the
conditions change?
26. What does Le Chatelier's The e ects of changing conditions on a system at equilibrium
principle predict?
27. What a ect will chang- The system will no longer be in equilibrium and the concentration of
ing the concentration of all the substances will change until equilibrium is reached again
one of the reactants in a
Exam – Actual Exam Questions with Detailed
Answers | Newest Update 2025/2026
1. How do you measure the By measuring the quantity of a reactant used or the quantity of product
rate of a reaction? formed over time
2. What is the equation Mean rate of reaction = quantity of reactant used/time taken
for calculating the mean
rate of a reaction by
measuring the amount
of reactant used?
3. What is the equation Mean rate of reaction = quantity of product formed/time taken
for calculating the mean
rate of a reaction by
measuring the amount
of product formed?
4. What units can you mea- g/s or cm3/s or mol/s
sure the rate of a reac-
tion in?
5. How do you calculate the By measuring the gradient of a tangent drawn at that speci�c time on
rate of a reaction at a the graph
speci�c time from graph
of the quantity of reac-
tant used or the quantity
of product formed?
6. What are the �ve factors Concentration of reactants in solution, pressure of reacting gases,
that can a ect the rate of surface area of solid reactants, temperature and the presence of a
a reaction? catalyst
7. What theory can we use Collision theory
to explain how various
, factors a ect the rate of
a reaction?
8. What is collision theory? Chemical reactions can occur only when reacting particles collide with
each other and with su cient energy
9. What is the activation The minimum amount of energy that particles must have to react
energy of a reaction?
10. According to collision It increases the frequency of collisions and so increases the rate of
theory why does increas- reaction
ing concentration of re-
actant in solution in-
crease the rate of the re-
action?
11. According to collision It increases the frequency of collisions and so increases the rate of
theory why does increas- reaction
ing the pressure of react-
ing gases increase the
rate of the reaction?
12. According to collision It increases the frequency of collisions and so increases the rate of
theory why does increas- reaction
ing the surface area of
solid reactants in solu-
tion increase the rate of
the reaction?
13. According to collision It increases the frequency of collisions and makes the collision more
theory why does in- energetic and so increases the rate of reaction
creasing temperature in-
, crease the rate of the re-
action?
14. How do you increase the Grind it into a powder that has smaller particle size
surface area of a solid re-
actant?
15. What e ect does in- It doubles it
creasing the tempera-
ture of a reaction by 10°C
have on the rate of a re-
action?
16. What is a catalyst? A chemical that changes the rate of a chemical reaction but is not used
up in the reaction
17. How do catalysts in- By providing a di erent pathway for the reaction that has a lower
crease the rate of a reac- activation energy
tion?
18. How do you know in a It is not included in the chemical equation for the reaction
reaction that a chemical
is used in a reaction is a
catalyst?
19. What is a reversible reac- Where the products of a chemical reaction can react to produce the
tion? original reactants
20. What is the symbol used
in reversible reaction
equations that shows
that the reaction is re-
versible?
, 21. How can you change the By changing the conditions; for example heating or cooling the reac-
direction of a reversible tion
reaction?
22. Describe the energy One direction will be exothermic and the other direction endothermic
changes in a reversible
reaction
23. When is equilibrium in When the rate of the forward and reverse reactions occur at exactly the
a reversible reaction same rate
achieved in apparatus
which prevents the es-
cape of reactants and
products?
24. What a ects the rela- The conditions
tive amount of all the
reactants and products
at equilibrium in a re-
versible reaction?
25. What happens to an The system responds to counteract the change
equilibrium if any of the
conditions change?
26. What does Le Chatelier's The e ects of changing conditions on a system at equilibrium
principle predict?
27. What a ect will chang- The system will no longer be in equilibrium and the concentration of
ing the concentration of all the substances will change until equilibrium is reached again
one of the reactants in a
