Rates of reaction
4 lessons in The rate and extent of chemical change.
24 exam questions · 50 marks
6.1
Measuring the rate of reaction
How to measure the rate of a reaction from the amount of reactant used or product formed over time, using gas volume, loss of mass or a colour change, how to calculate a mean rate, and (Higher) how to find the rate at a moment from the gradient of a tangent.
AQA
Edexcel
OCR
6 questions
6.2
Collision theory and factors affecting rate
Collision theory: reactions happen when particles collide with at least the activation energy. How concentration, pressure, surface area and temperature change the frequency and energy of collisions, and so the rate.
AQA
Edexcel
OCR
6 questions
6.3
Catalysts
What catalysts are, how they increase the rate of reaction by providing a pathway with a lower activation energy, how to show this on a reaction profile, how to identify a catalyst, and enzymes as biological catalysts.
AQA
Edexcel
OCR
6 questions
6.4
Required practical: rates of reaction
The required practical on how concentration affects the rate of reaction: the disappearing cross method with sodium thiosulfate and acid, the gas collection method with marble chips or magnesium, variables, calculating 1/time, and improving accuracy.
AQA
Edexcel
OCR
6 questions