The Rate of Chemical Change


Chemical Reactions involve rearrangement of atoms in substances to form new substances.

This topic looks at how to measure and alter the speed of chemical reactions (Rate of reaction).

The Essentials

Rates of reaction can be explained by Collision Theory. This states that in order for any particles to react they must collide with each other with enough energy to cause a reaction. The greater the number of collisions the more chance of a reaction and the harder the collisions the greater the chance of a reaction. You must be able to explain how to change the rate of reaction be linking it to collision theory.

Make sure you can explain why each of these factors alters rate of reaction.

Temperature, concentration, pressure, surface area and catalysts.

You must also know how to plan and evaluate experiments to measure rate of reaction when concentration of a reactant is changed.

100 % Practical Rates    

100% rates

Rates and temperature-revision-flashcards

Deeper Understanding

Other Links

BBC Bitesize – Rates of Reaction

MyGCSEScience -Rates

Review and Rate your Understanding

After revising the topic and completing the questions of the 100% sheet try the end of topic summary questions (answers given) and then print and complete the checklist to rate your understanding.



Have you learnt all the facts on the 100% sheet?

Have you completed the BBC Bitesize tutorial?

Have you been able to complete all the questions on the 100% sheet?

Let us know how you feel about this topic in the comments section below. Any questions you have, just ask