GCSE WJEC Rates of reaction Activation energy [Higher tier only] Chemical reactions vary in speed. The rate of reaction measures how much product is made in a given time.

In the course of work on the kinetics of this solid state reaction, the problem arose of deducing the reaction constant and the activation energy without exact knowledge of the reaction mechanism ...

Learn about and revise energy, rates and reactions with this BBC Bitesize Combined Science AQA Synergy study guide.