Reduction at the cathode in molten NaCl electrolysis

Steps:

• Cathode is the negative electrode where reduction (gain of electrons) occurs.
• Molten NaCl provides Na⁺ cations and Cl⁻ anions.
• Na⁺ ions migrate to the cathode and accept electrons to form Na atoms.
• Thus, sodium ions undergo reduction.

Why B is correct:

• Reduction involves gain of electrons, as in Na⁺ + e⁻ → Na.

Why the others are wrong:

• A: Oxidation (loss of electrons) occurs at the anode, not cathode.
• C: Chloride ions are oxidized at the anode to form Cl₂.
• D: Chloride ions are oxidized, but at the anode, not cathode.

Final answer: B