MHTCET 10 May 2024 Shift 2 Paper

Concept: Standard cell potential is the difference between the cathode and anode reduction potentials.Explanation: The given cell notation is $\mathrm{Al}\left|\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3(1 \mathrm{M})}\right|\left|\mathrm{HCl}_{(1 \mathrm{M})}\right| \mathrm{H}_{2(\mathrm{~g})(1 \mathrm{~atm})}, \mathrm{Pt}$. Here, aluminium is the anode and the standard hydrogen electrode is the cathode. At the anode, oxidation occurs: $\mathrm{Al} \rightarrow \mathrm{Al}^{3+}+3e^{-}$, with $E^{\circ}=+1.66\ \mathrm{V}$. At the cathode, reduction occurs: $2\mathrm{H}^{+}+2e^{-}\rightarrow \mathrm{H}_{2}$, with $E^{\circ}=0\ \mathrm{V}$. The cell potential is given by $E_{\text{cell}}^{\circ}=E_{\text{cathode}}^{\circ}-E_{\text{anode}}^{\circ}$. Substituting the values: $E_{\text{cell}}^{\circ}=0\ \mathrm{V}-(-1.66\ \mathrm{V})=+1.66\ \mathrm{V}$. Hence, the standard cell potential is positive and equals $+1.66\ \mathrm{V}$.Answer: Option A: $1.66\ \mathrm{V}$