Why can a catalyst increase rate without changing the products?
It supplies extra atoms that become part of the products
It changes the reaction pathway, not the overall reaction
It gives the reactant particles extra kinetic energy to react
It increases the overall energy released by the reaction
54 exam-style questions on Edexcel GCSE Chemistry 8.1 Rates of reaction, covering 8.1.1 Measuring and interpreting rates of reaction, 8.1.2 Collision theory and the factors affecting rate, and 8.1.3 Catalysts and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.