If we use molten NaCl , the products of electrolysis are______.

The correct answer is Option (4) → Sodium metal and \(Cl_2\) gas

Molten NaCl contains only \( \ce{Na^{+}} \) and \( \ce{Cl^{-}} \) ions; there is no water.

    \( \displaystyle \text{Cathode: }\ce{Na+ + e^- -> Na(l)} \)

    \( \displaystyle \text{Anode: }\ce{Cl^- -> 1/2Cl2(g) + e^-} \)

    \( \displaystyle \text{Net: }\ce{2NaCl(l) -> 2Na(l) + Cl2(g)} \)

So the products are sodium metal at the cathode and chlorine gas at the anode.

Why the other options are incorrect

• Option (1) H₂ gas and Cl₂ gas — Incorrect. \( \ce{H2} \) forms at the cathode only in aqueous NaCl, where water is reduced in preference to \( \ce{Na^{+}} \).

• Option (2) NaOH and Cl₂ gas — Incorrect. NaOH is produced in the electrolysis of aqueous NaCl (from the \( \ce{OH^{-}} \) left when water is reduced); molten NaCl has no water.

• Option (3) H₂O and Cl₂ gas — Incorrect. Water is not formed in this electrolysis, and there is no hydrogen or oxygen in molten NaCl to form it.

NCERT (2026-27 edition):
Products of Electrolysis – “… The products of electrolysis depend on the different oxidising and reducing species present in the electrolytic cell and their standard electrode potentials. … For example, if we use molten NaCl, the products of electrolysis are sodium metal and Cl₂ gas. Here we have only one cation (Na⁺) which is reduced at the cathode (Na⁺ + e^– → Na) and one anion (Cl^–) which is oxidised at the anode (Cl^– → ½Cl₂ + e^–). During the electrolysis of aqueous sodium chloride solution, the products are NaOH, Cl₂ and H₂. In this case besides Na⁺ and Cl^– ions we also have H⁺ and OH^– ions along with the solvent molecules, H₂O.”