During a reaction, 7.2 g of a solid reactant was used up in 3.0 minutes3.0\ \text{minutes}3.0 minutes. What was the mean rate at which the reactant was used up in g/s\text{g/s}g/s?
2.4 g/s2.4\ \text{g/s}2.4 g/s
0.42 g/s0.42\ \text{g/s}0.42 g/s
22 g/s22\ \text{g/s}22 g/s
0.040 g/s0.040\ \text{g/s}0.040 g/s
127 exam-style questions on AQA GCSE Chemistry 6.1 Rate of reaction, covering 6.1.1a Calculating rates of reactions, 6.1.1b Gradient of a tangent as rate, 6.1.2 Factors which affect the rates of chemical reactions, 6.1.3 Collision theory and activation energy, and 6.1.4 Catalysts. Each one has a worked solution and a mark scheme showing where the marks go.