Which profile change represents adding a catalyst?
A lower peak but the same reactant and product levels
A lower reactant energy level with the same peak height
A higher product energy level with the same peak height
A lower peak together with a larger overall energy change
94 exam-style questions on Edexcel GCSE Chemistry 8.2 Heat energy changes in chemical reactions, covering 8.2.1 Exothermic and endothermic changes, 8.2.2 Bond breaking, bond making and overall energy change, 8.2.3 Calculating energy change from bond energies, and 8.2.4 Activation energy and reaction profiles. Each one has a worked solution and a mark scheme showing where the marks go.