AQA GCSE Chemistry Paper 2 Verified Solutions
1. How can you measure the rate of a reaction?
Answer: By measuring the quantity of reactant used or product formed over time
2. What is the formula for calculating the mean rate of reaction when measuring reactant quantity?
Answer: Mean rate of...
AQA GCSE Chemistry Paper 2 Verified Solutions
1. How can you measure the rate of a reaction?
Answer: By measuring the quantity of reactant used or product formed over time
2. What is the formula for calculating the mean rate of reaction when measuring reactant quantity?
Answer: Mean rate of reaction = quantity of reactant used / time taken
3. What is the formula for calculating the mean rate of reaction when measuring product quantity?
Answer: Mean rate of reaction = quantity of product formed / time taken
4. In what units can you measure the rate of a reaction?
Answer: Grams per second (g/s), cubic centimeters per second (cm³/s), or moles per second (mol/s)
5. How do you calculate the rate of a reaction at a specific time from a graph?
Answer: By finding the gradient of a tangent drawn at that specific time on the graph
6. What are the five factors that can affect the rate of a chemical reaction?
Answer: Concentration of reactants, pressure of reacting gases, surface area of solid reactants,
temperature, and presence of catalysts
7. What theory explains how various factors influence the rate of a chemical reaction?
Answer: Collision theory
,8. What is collision theory in simple terms?
Answer: Chemical reactions occur only when particles collide with sufficient energy and frequency
9. What is activation energy, and what role does it play in collision theory?
Answer: It's the minimum energy required for particles to react; increasing activation energy slows
down reactions, while decreasing it speeds them up
10. How do increasing concentration, pressure, surface area, and temperature affect the rate of a
reaction according to collision theory?
Answer: Increasing these factors increases the frequency and energy of collisions, thus increasing the
rate of reaction
11. How can you increase the surface area of solid reactants?
Answer: By grinding them into smaller particles or powders
12. What happens to the rate of reaction when temperature increases by 10°C?
Answer: It doubles
13. What is a catalyst, and how does it work?
Answer: A chemical that changes the rate of a reaction without being consumed; it provides an
alternative pathway with lower activation energy
14. How can you identify whether a substance is a catalyst in a reaction?
, Answer: If it's not included in the chemical equation
15. What is a reversible reaction, and how can you change its direction?
Answer: A reaction where products can re-form reactants; direction can be changed by adjusting
conditions such as temperature or concentration
Describe the energy changes in a reversible reaction ✔️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? ✔️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? ✔️The conditions
What happens to an equilibrium if any of the conditions change? ✔️The system responds to counteract
the change
What does Le Chatelier's principle predict? ✔️The effects of changing conditions on a system at
equilibrium
What affect will changing the concentration of one of the reactants in a reversible reaction have on the
equilibrium? ✔️The system will no longer be in equilibrium and the concentration of all the substances
will change until equilibrium is reached again
What happens when the concentration of a reactant is increased in a reversible reaction? ✔️More
products will be formed until equilibrium is reached again
What happens when the concentration of a product is decreased in a reversible reaction? ✔️More
reactant will react until equilibrium is reached again
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller bestscores1. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R196,91. You're not tied to anything after your purchase.
