A voltaic cell is made by connecting two half cells represented by the half equations below: $$\mathrm{Sn^{2+}(aq)}+2e^-\rightarrow\mathrm{Sn(s)};\ E^{\circ}=-0.14\ \mathrm{V}$$ $$\mathrm{Fe^{3+}(aq)}+e^-\rightarrow\mathrm{Fe^{2+}(aq)};\ E^{\circ}=+0.77\ \mathrm{V}$$ Which statement is correct about this voltaic cell?

(B) Sn is oxidized and the voltage of the cell is 0.91 V

(A) Fe$^{2+}$ is oxidized and the voltage of the cell is −0.91 V

(C) Fe$^{2+}$ is oxidized and the voltage of the cell is 0.91 V

(D) Sn is oxidized and the voltage of the cell is 0.63 V

CBSE Class 12 · 2023 · Redox Reactions and ElectrochemistryMultiple Choice

A voltaic cell is made by connecting two half cells represented by the half equations below:

S n^{2 +} (aq) + 2 e^{-} \to Sn (s); E^{\circ} = - 0.14 V

F e^{3 +} (aq) + e^{-} \to F e^{2 +} (aq); E^{\circ} = + 0.77 V

Which statement is correct about this voltaic cell?

Answer: (B)

The couple with the lower reduction potential is oxidised: Sn (−0.14 V) is the anode.

E_{ce l l}^{\circ} = 0.77 - (- 0.14) = 0.91 V

So tin is oxidised and the cell voltage is 0.91 V.

CBSE Class 12 Board · 2023 · Single correct option