Which statement about a catalyst in a reaction is correct?
It is used up while the reaction takes place
It is one of the products of the reaction
It is not used up during the reaction
It is always an enzyme from a living cell
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.