Aqueous sodium chloride, when dilute, is electrolysed with platinum electrodes. What is the half-equation for the reaction at the cathode?
- A$2\text{H}^+ + 2e^- \rightarrow \text{H}_2$
- B$\text{Na}^+ + e^- \rightarrow \text{Na}$
- C$2\text{Cl}^- \rightarrow \text{Cl}_2 + 2e^-$
- D$4\text{OH}^- \rightarrow 2\text{H}_2\text{O} + \text{O}_2 + 4e^-$