Question

In the electrolysis of molten \( \mathrm{NaCl} \), what is produced at the cathode?

• A. Chlorine gas
• B. Sodium metal
• C. Hydrogen gas
• D. Oxygen gas

Hint:

Cations are reduced at the cathode; anions are oxidized at the anode.

Answer 1

The Correct Option is B

During the electrolysis of molten \( \mathrm{NaCl} \), an ionic compound comprising sodium ions (\( \mathrm{Na}^+ \)) and chloride ions (\( \mathrm{Cl}^- \)), the product at the cathode is identified.

Electrolysis requires melting the compound to liberate ions for electrode migration. The cathode, being negatively charged, attracts positively charged cations.

The electrode reactions in molten \( \mathrm{NaCl} \) electrolysis are:

• Cathode: \( \mathrm{Na}^+ \) ions gain electrons, undergoing reduction to form sodium metal.
  \( \mathrm{Na}^+ + e^- \rightarrow \mathrm{Na} \)
• Anode: \( \mathrm{Cl}^- \) ions lose electrons, undergoing oxidation to form chlorine gas.
  \( 2\mathrm{Cl}^- \rightarrow \mathrm{Cl}_2 + 2e^- \)

As the cathode attracts \( \mathrm{Na}^+ \) ions, which are then reduced to sodium metal, the substance produced at the cathode in the electrolysis of molten \( \mathrm{NaCl} \) is sodium metal.