Iron powder reacts with oxygen in a disposable hand warmer.
Which statement describes the energy transfer in this reaction and the energy of the products compared with the reactants?
Energy is transferred to the surroundings; products are at a lower energy than reactants.
Energy is taken in from the surroundings; products are at a higher energy than reactants.
Energy is transferred to the surroundings; products are at a higher energy than reactants.
Energy is taken in from the surroundings; products are at a lower energy than reactants.
106 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.