When sodium thiosulfate solution is mixed with dilute hydrochloric acid the mixture slowly turns cloudy. How can the rate of this reaction be measured?
By weighing the mixture as the reaction happens
By collecting the gas that the reaction gives off
By timing how long a printed mark takes to vanish
By measuring the temperature rise of the mixture
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.