Marble chips are added to dilute hydrochloric acid. The reaction gets slower and then stops while marble chips are still left in the flask. Why does the reaction stop?
The marble chips have lost all of their surface area
All of the hydrochloric acid has been used up
The temperature of the mixture has become too low
The acid particles no longer have enough energy
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.