Which of the following substances: Na, Hg, S, Pt and graphite can be used as electrodes in electroly — Electrochemistry Chemistry Question

💡 Solution & Explanation

Electrodes used in aqueous solutions must not react violently with water. Platinum (Pt) and graphite are inert electrodes. Mercury (Hg) can be used as a cathode (e.g., in the Castner-Kellner process). Sodium (Na) reacts explosively with water, and Sulfur (S) is a non-metal insulator, rendering them unusable as solid electrodes. Therefore, correct answer is C.