Rate from concentration-time graphs
Rate from concentration-time graphs

The rate of reaction is the change in concentration per unit time, usually measured in mol dm−3 s−1\text{mol dm}^{-3} \text{ s}^{-1}mol dm−3 s−1. For a reactant, concentration falls, so the gradient is negative and we report rate as the negative of that gradient.
Step-by-step lessons covering Edexcel A Level Chemistry Rate equations for A Level Chemistry. Each lesson works through exam-style questions in Paper 1, Paper 2 and Paper 3 format. Build confidence with atomic structure, bonding and moles calculations early on, since these underpin the more demanding organic mechanisms, equilibrium and practical-analysis topics that dominate Year 2.