When molten NaCl is electrolyzed, which products are formed at the cathode and anode, respectively?

• A. Cathode: H_2; Anode: Cl_2
• B. Cathode: NaCl; Anode: O_2
• C. Cathode: Na; Anode: Cl_2
• D. Cathode: Cl_2; Anode: Na

Answer: (C)

Verified step by step guidance

1. Identify the species present in molten NaCl. Since it is molten, NaCl is dissociated into Na⁺ and Cl⁻ ions, with no water present to participate in the reaction.
2. At the cathode (the site of reduction), cations gain electrons. Here, Na⁺ ions will be reduced to sodium metal (Na) by gaining electrons: \(\mathrm{Na^{+} + e^{-} \rightarrow Na}\).
3. At the anode (the site of oxidation), anions lose electrons. Chloride ions (Cl⁻) will be oxidized to chlorine gas (Cl₂) by losing electrons: \(\mathrm{2Cl^{-} \rightarrow Cl_2 + 2e^{-}}\).
4. Confirm that no other species (like H₂ or O₂) are produced because the system is molten NaCl without water, so water electrolysis products are not involved.
5. Summarize the products: sodium metal (Na) forms at the cathode, and chlorine gas (Cl₂) forms at the anode.