Which statement must be true for every exothermic reaction?
The activation energy is smaller than the energy given out.
The reaction starts without any energy being supplied.
The reverse reaction is endothermic and has a larger activation energy than the forward reaction.
The surroundings stay at a higher temperature after the reaction has finished.
51 exam-style questions on OCR GCSE Chemistry 3.2 Energetics, covering 3.2.1 Exothermic and endothermic reactions and reaction profiles and 3.2.2 Calculating energy change from bond energies. Each one has a worked solution and a mark scheme showing where the marks go.