BITSAT 2022 Paper

(a) $2\mathrm{Fe}^{3+} + 2e^{-} \rightarrow 2\mathrm{Fe}^{2+} ; E^{\circ}=0.77\mathrm{V}$ $2\mathrm{I}^{-} \rightarrow \mathrm{I}_2 + 2e^{-}; E^{\circ}=-0.54\mathrm{V} \text{ (sign of } E^{\circ} \text{ is reversed) }$ ___________________________________________ $2\mathrm{Fe}^{3+} + 2\mathrm{I}^{-} \rightarrow 2\mathrm{Fe}^{2+} + \mathrm{I}_2; E^{\circ}_{\mathrm{cell}}=+0.23\mathrm{V}$ ___________________________________________ This reaction is feasible, since $E^{\circ}_{\mathrm{cell}}$ is positive. (b) $\mathrm{Cu} \rightarrow \mathrm{Cu}^{2+} + 2e^{-}; E^{\circ}=-0.34\mathrm{V} \text{ (sign of } E^{\circ} \text{ gas been reversed)}$ $2\mathrm{Ag}^{+} + 2e^{-} \rightarrow 2\mathrm{Ag}; E^{\circ}=+0.80\mathrm{V}$ ___________________________________________ $\mathrm{Cu} + 2\mathrm{AG}^{+} \rightarrow \mathrm{Cu}^{2+} + 2\mathrm{Ag}; E^{\circ}=+0.46\mathrm{V}$ ___________________________________________ This reaction is feasible, since $E^{\circ}_{\mathrm{cell}}$ is positive. (c) $2\mathrm{Fe}^{3+} + 2e^{-} \rightarrow 2\mathrm{Fe}^{2+} ; E^{\circ}=+0.77\mathrm{V}$ $\mathrm{Cu} \rightarrow \mathrm{Cu}^{2+} + 2e^{-}; E^{\circ}=-34\mathrm{V} \text{ (sign of } E^{\circ} \text{ is reversed)}$ ___________________________________________ $2\mathrm{Fe}^{3+} + \mathrm{Cu} \rightarrow \mathrm{Fe}^{2+} + \mathrm{Cu}^{2+}; E^{\circ}=+0.43\mathrm{V}$ ___________________________________________ This reaction is feasible, since $E^{\circ}_{\mathrm{cell}}$ is positive. (d) $\mathrm{Ag} \rightarrow \mathrm{Ag}^{+} + e^{-}; E^{\circ}=-0.80\mathrm{V} \text{ (sign of } E^{\circ} \text{ is reversed) }$ $\mathrm{Fe}^{3+} + e^{-} \rightarrow \mathrm{Fe}^{2+}; E^{\circ}=+0.77\mathrm{V}$ ___________________________________________ $\mathrm{Ag} + \mathrm{Fe}^{3+} \rightarrow \mathrm{Ag}^{+} + \mathrm{Fe}^{2+} ; E^{\circ} = -0.03\mathrm{V}$ ___________________________________________ This reaction is not feasible, since $E^{\circ}_{\mathrm{cell}}$ is negative.