24.1.1—The identities of substances liberated during

At the cathode reduction occurs; at the anode oxidation occurs. In molten salts the ions present decide the products, while aqueous solutions also contain water and product selection depends on relative electrode potentials and concentration.

List all plausible half-equations, compare their ease of discharge, then balance electrons. Concentration can make a less favourable species discharge preferentially at an inert electrode.

Molten NaCl gives Na at the cathode and Cl₂ at the anode. Aqueous NaCl generally gives H₂ at the cathode and Cl₂ at the anode under concentrated brine conditions.

Do not transfer molten predictions to aqueous electrolysis without including water as a competing reactant.