Molten sodium iodide contains Na+\mathrm{Na^{+}}Na+ ions and I−\mathrm{I^{-}}I− ions. During electrolysis, sodium atoms form at one electrode and iodine molecules form at the other electrode.
Write the half equation for the reaction at each electrode. Then combine the two half equations to write the overall ionic equation for the electrolysis.
134 exam-style questions on OCR GCSE Chemistry 3.1 Introducing chemical reactions, covering 3.1.1 Writing formulae and balanced chemical equations, 3.1.2 Formulae of compounds from ions, and state symbols, 3.1.3 Conservation of mass and observed changes in mass, 3.1.4 Half equations and balanced ionic equations, 3.1.5 The mole and the Avogadro constant, and 3.1.6 Stoichiometry, limiting reactants and reacting masses. Each one has a worked solution and a mark scheme showing where the marks go.