An aqueous solution of copper(II) sulfate (CuSO4\text{CuSO}_4CuSO4) is electrolysed using inert graphite electrodes, as shown in the diagram below.
Which of the following options correctly identifies both the pair of ions attracted to the positive electrode (anode) and the half-equation for the reaction that occurs there?
Ions attracted: SO42−\text{SO}_4^{2-}SO42− and OH−\text{OH}^-OH−; Half-equation: 4OH−→O2+2H2O+4e−4\text{OH}^- \rightarrow \text{O}_2 + 2\text{H}_2\text{O} + 4\text{e}^-4OH−→O2+2H2O+4e−
Ions attracted: Cu2+\text{Cu}^{2+}Cu2+ and H+\text{H}^+H+; Half-equation: Cu2++2e−→Cu\text{Cu}^{2+} + 2\text{e}^- \rightarrow \text{Cu}Cu2++2e−→Cu
Ions attracted: SO42−\text{SO}_4^{2-}SO42− and OH−\text{OH}^-OH−; Half-equation: Cu→Cu2++2e−\text{Cu} \rightarrow \text{Cu}^{2+} + 2\text{e}^-Cu→Cu2++2e−
Ions attracted: SO42−\text{SO}_4^{2-}SO42− and OH−\text{OH}^-OH−; Half-equation: 2H++2e−→H22\text{H}^+ + 2\text{e}^- \rightarrow \text{H}_22H++2e−→H2
Electrolytic processes Questions
Practise Edexcel GCSE Chemistry Electrolytic processes with exam-style questions for Foundation and Higher tier. 100 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.