AQA GCSE Chemistry Paper 2 questions
and answers 2024
How do you measure the rate of a reaction? - (answers)By measuring the quantity of a reactant
used or the quantity of product formed over time
What is the equation for calculating the mean rate of a reaction by measuring the amount of
reactant used? - (answers)Mean rate of reaction = quantity of reactant used/time taken
What is the equation for calculating the mean rate of a reaction by measuring the amount of
product formed? - (answers)Mean rate of reaction = quantity of product formed/time taken
What units can you measure the rate of a reaction in? - (answers)g/s or cm3/s or mol/s
How do you calculate the rate of a reaction at a specific time from graph of the quantity of
reactant used or the quantity of product formed? - (answers)By measuring the gradient of a
tangent drawn at that specific time on the graph
What are the five factors that can affect the rate of a reaction? - (answers)Concentration of
reactants in solution, pressure of reacting gases, surface area of solid reactants, temperature and
the presence of a catalyst
What theory can we use to explain how various factors affect the rate of a reaction? -
(answers)Collision theory
What is collision theory? - (answers)Chemical reactions can occur only when reacting particles
collide with each other and with sufficient energy
What is the activation energy of a reaction? - (answers)The minimum amount of energy that
particles must have to react
,According to collision theory why does increasing concentration of reactant in solution increase
the rate of the reaction? - (answers)It increases the frequency of collisions and so increases the
rate of reaction
According to collision theory why does increasing the pressure of reacting gases increase the rate
of the reaction? - (answers)It increases the frequency of collisions and so increases the rate of
reaction
According to collision theory why does increasing the surface area of solid reactants in solution
increase the rate of the reaction? - (answers)It increases the frequency of collisions and so
increases the rate of reaction
According to collision theory why does increasing temperature increase the rate of the reaction? -
(answers)It increases the frequency of collisions and makes the collision more energetic and so
increases the rate of reaction
How do you increase the surface area of a solid reactant? - (answers)Grind it into a powder that
has smaller particle size
What effect does increasing the temperature of a reaction by 10°C have on the rate of a reaction?
- (answers)It doubles it
What is a catalyst? - (answers)A chemical that changes the rate of a chemical reaction but is not
used up in the reaction
How do catalysts increase the rate of a reaction? - (answers)By providing a different pathway for
the reaction that has a lower activation energy
, How do you know in a reaction that a chemical is used in a reaction is a catalyst? - (answers)It is
not included in the chemical equation for the reaction
What is a reversible reaction? - (answers)Where the products of a chemical reaction can react to
produce the original reactants
What is the symbol used in reversible reaction equations that shows that the reaction is
reversible? - (answers)
How can you change the direction of a reversible reaction? - (answers)By changing the
conditions; for example heating or cooling the reaction
Describe the energy changes in a reversible reaction - (answers)One direction will be exothermic
and the other direction endothermic
When is equilibrium in a reversible reaction achieved in apparatus which prevents the escape of
reactants and products? - (answers)When the rate of the forward and reverse reactions occur at
exactly the same rate
What affects the relative amount of all the reactants and products at equilibrium in a reversible
reaction? - (answers)The conditions
What happens to an equilibrium if any of the conditions change? - (answers)The system responds
to counteract the change
What does Le Chatelier's principle predict? - (answers)The effects of changing conditions on a
system at equilibrium
and answers 2024
How do you measure the rate of a reaction? - (answers)By measuring the quantity of a reactant
used or the quantity of product formed over time
What is the equation for calculating the mean rate of a reaction by measuring the amount of
reactant used? - (answers)Mean rate of reaction = quantity of reactant used/time taken
What is the equation for calculating the mean rate of a reaction by measuring the amount of
product formed? - (answers)Mean rate of reaction = quantity of product formed/time taken
What units can you measure the rate of a reaction in? - (answers)g/s or cm3/s or mol/s
How do you calculate the rate of a reaction at a specific time from graph of the quantity of
reactant used or the quantity of product formed? - (answers)By measuring the gradient of a
tangent drawn at that specific time on the graph
What are the five factors that can affect the rate of a reaction? - (answers)Concentration of
reactants in solution, pressure of reacting gases, surface area of solid reactants, temperature and
the presence of a catalyst
What theory can we use to explain how various factors affect the rate of a reaction? -
(answers)Collision theory
What is collision theory? - (answers)Chemical reactions can occur only when reacting particles
collide with each other and with sufficient energy
What is the activation energy of a reaction? - (answers)The minimum amount of energy that
particles must have to react
,According to collision theory why does increasing concentration of reactant in solution increase
the rate of the reaction? - (answers)It increases the frequency of collisions and so increases the
rate of reaction
According to collision theory why does increasing the pressure of reacting gases increase the rate
of the reaction? - (answers)It increases the frequency of collisions and so increases the rate of
reaction
According to collision theory why does increasing the surface area of solid reactants in solution
increase the rate of the reaction? - (answers)It increases the frequency of collisions and so
increases the rate of reaction
According to collision theory why does increasing temperature increase the rate of the reaction? -
(answers)It increases the frequency of collisions and makes the collision more energetic and so
increases the rate of reaction
How do you increase the surface area of a solid reactant? - (answers)Grind it into a powder that
has smaller particle size
What effect does increasing the temperature of a reaction by 10°C have on the rate of a reaction?
- (answers)It doubles it
What is a catalyst? - (answers)A chemical that changes the rate of a chemical reaction but is not
used up in the reaction
How do catalysts increase the rate of a reaction? - (answers)By providing a different pathway for
the reaction that has a lower activation energy
, How do you know in a reaction that a chemical is used in a reaction is a catalyst? - (answers)It is
not included in the chemical equation for the reaction
What is a reversible reaction? - (answers)Where the products of a chemical reaction can react to
produce the original reactants
What is the symbol used in reversible reaction equations that shows that the reaction is
reversible? - (answers)
How can you change the direction of a reversible reaction? - (answers)By changing the
conditions; for example heating or cooling the reaction
Describe the energy changes in a reversible reaction - (answers)One direction will be exothermic
and the other direction endothermic
When is equilibrium in a reversible reaction achieved in apparatus which prevents the escape of
reactants and products? - (answers)When the rate of the forward and reverse reactions occur at
exactly the same rate
What affects the relative amount of all the reactants and products at equilibrium in a reversible
reaction? - (answers)The conditions
What happens to an equilibrium if any of the conditions change? - (answers)The system responds
to counteract the change
What does Le Chatelier's principle predict? - (answers)The effects of changing conditions on a
system at equilibrium
