Iron is a typical transition metal. It forms iron(II) ions, Fe2+\mathrm{Fe^{2+}}Fe2+, and iron(III) ions, Fe3+\mathrm{Fe^{3+}}Fe3+. An oxide ion is O2−\mathrm{O^{2-}}O2−.
Give the formulae of iron(II) chloride and iron(III) oxide.
Iron(II) sulfate solution is pale green. When it is left in air, it slowly turns yellow-brown because the Fe2+\mathrm{Fe^{2+}}Fe2+ ions change into Fe3+\mathrm{Fe^{3+}}Fe3+ ions.
Write the half equation for the change of Fe2+\mathrm{Fe^{2+}}Fe2+ ions into Fe3+\mathrm{Fe^{3+}}Fe3+ ions.
Explain whether the Fe2+\mathrm{Fe^{2+}}Fe2+ ions are oxidised or reduced.
Iron is used as a catalyst in the Haber process. Explain how a catalyst increases the rate of a reaction.
Sodium hydroxide solution is added to the yellow-brown solution containing Fe3+\mathrm{Fe^{3+}}Fe3+ ions. A precipitate forms. Give the colour of the precipitate and write the ionic equation for its formation. Include state symbols.
42 exam-style questions on Edexcel GCSE Chemistry 6.1 Transition metals, alloys and corrosion, covering 6.1.1 Properties of transition metals, 6.1.2 Corrosion and its prevention, and 6.1.3 Alloys and the uses of metals. Each one has a worked solution and a mark scheme showing where the marks go.