(a) What is electrolysis? (b) Are electrolysis reactions thermodynamically spontaneous? (c) What process occurs at the anode in the electrolysis of molten \(\mathrm{NaCl}\) (d) Why is sodium metal not obtained when an aqueous solution of NaCl undergoes electrolysis?

(a) Electrolysis is a non-spontaneous process in which electrical energy is used to drive chemical reactions, leading to the decomposition of a compound. (b) Electrolysis reactions are not thermodynamically spontaneous, as they require an external source of electrical energy. (c) In the electrolysis of molten NaCl, chloride ions are oxidized at the anode to form chlorine gas, with the half-reaction: \(2\mathrm{Cl}^-(l) \rightarrow \mathrm{Cl}_2(g) + 2e^-\). (d) Sodium metal is not obtained during electrolysis of aqueous NaCl solution because water has a lower reduction potential than sodium, and its reduction at the cathode is favored over sodium ions, with the half-reaction: \(2\mathrm{H}_2\mathrm{O}(l) + 2e^- \rightarrow \mathrm{H}_2(g) + 2\mathrm{OH}^-(aq)\).