What is the half equation for the reaction at the cathode in an acidic hydrogen/oxygen fuel cell?
2H2+O2→2H2O2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}2H2+O2→2H2O
2H2→4H++4e−2\text{H}_2 \rightarrow 4\text{H}^+ + 4\text{e}^-2H2→4H++4e−
O2+4H++4e−→2H2O\text{O}_2 + 4\text{H}^+ + 4\text{e}^- \rightarrow 2\text{H}_2\text{O}O2+4H++4e−→2H2O
4H++4e−→2H24\text{H}^+ + 4\text{e}^- \rightarrow 2\text{H}_24H++4e−→2H2
81 exam-style questions on OCR GCSE Chemistry Improving processes and products. Each one has a worked solution and a mark scheme showing where the marks go.