The cell reaction for the given cell is spontaneous if Pt, Cl2 (P1 atm) \| Cl– \| Cl2 (P2 atm), Pt — Electrochemistry Chemistry Question

💡 Solution & Explanation

This is a gas concentration cell. Anode: $2Cl^- \rightarrow Cl_2(P_1) + 2e^-$. Cathode: $Cl_2(P_2) + 2e^- \rightarrow 2Cl^-$. The overall reaction is $Cl_2(P_2) \rightarrow Cl_2(P_1)$. For the gas expansion to be spontaneous, it must move from a higher pressure to a lower pressure, so $P_2 > P_1$, or $P_1 < P_2$.