Calcium can be obtained by the electrolysis of calcium chloride. Solid calcium chloride is obtained from mineral deposits.
The calcium chloride is melted and then electrolysed. The positive electrode is made of graphite and the negative electrode is made of steel.
Calcium forms at the negative electrode. Chlorine forms at the positive electrode.
Explain why the calcium chloride has to be melted before it can be electrolysed.
Write an ionic half-equation to represent the formation of calcium at the negative electrode.
Suggest why steel is not used for the positive electrode.
21 exam-style questions on Edexcel IGCSE Chemistry Electrolysis. Each one has a worked solution and a mark scheme showing where the marks go.