During electroplating, copper metal is deposited onto a steel key. Which half-equation represents this reaction?
Cu→Cu2++2e−\text{Cu} \rightarrow \text{Cu}^{2+} + 2\text{e}^-Cu→Cu2++2e−
Cu2++2e−→Cu\text{Cu}^{2+} + 2\text{e}^- \rightarrow \text{Cu}Cu2++2e−→Cu
Cu2+→Cu+2e−\text{Cu}^{2+} \rightarrow \text{Cu} + 2\text{e}^-Cu2+→Cu+2e−
Cu+2e−→Cu2+\text{Cu} + 2\text{e}^- \rightarrow \text{Cu}^{2+}Cu+2e−→Cu2+
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.