During the operation of a commercial dry cell (Leclanché cell), which of the following accurately re — Electrochemistry Chemistry Question

💡 Solution & Explanation

In a dry cell, the graphite rod acts as the cathode and is surrounded by a paste of $MnO_2$ and carbon black. The ammonium ions ($NH_4^+$) from the electrolyte paste are reduced, and $MnO_2$ acts as a depolarizer. The overall cathodic reduction is $MnO_2 + NH_4^+ + e^- \rightarrow MnO(OH) + NH_3$. Manganese changes its oxidation state from $+4$ to $+3$.