In electrolysis, the electrolyte must be in which form to conduct electricity?

• A. Solid
• B. Molten or aqueous
• C. Gas
• D. Liquid metal

Answer: (B)

Electric current in electrolysis is carried by mobile ions. In a solid ionic compound, the ions are fixed in a lattice and can’t move, so the solid doesn’t conduct electricity to drive the electrolysis process. When the electrolyte is molten (a liquid salt) or dissolved in water (an aqueous solution), the ions are free to move and migrate to the electrodes under the applied voltage. These moving ions enable the necessary charge transport and enable the reduction and oxidation reactions at the electrodes. A gas isn’t a practical medium for conduction in this context, and a liquid metal isn’t the typical electrolyte used for electrolysis. So the electrolyte must be in molten or aqueous form to conduct electricity.