Calculate the standard cell potential of the galvanic cell in which the following reaction takes place: $$\mathrm{2Cr(s)+3Cd^{2+}(aq)\longrightarrow 2Cr^{3+}(aq)+3Cd(s)}$$ Also calculate the ΔG° value of the reaction. (Given: $E^{\circ}_{\mathrm{Cr^{3+}/Cr}} = -0.74$ V; $E^{\circ}_{\mathrm{Cd^{2+}/Cd}} = -0.40$ V and F = 96500 C mol$^{-1}$)

CBSE Class 12 · 2007 · All India · Redox Reactions and ElectrochemistryShort Answer

Calculate the standard cell potential of the galvanic cell in which the following reaction takes place:

2Cr (s) + 3C d^{2 +} (aq) ⟶ 2C r^{3 +} (aq) + 3Cd (s)

Also calculate the ΔG° value of the reaction.
(Given:

E_{C r^{3 +} /Cr}^{\circ} = - 0.74

E_{C d^{2 +} /Cd}^{\circ} = - 0.40

V and F = 96500 C mol

^{- 1}

)

Answer: E°_cell = 0.34 V; ΔG° ≈ −196.9 kJ mol⁻¹

Cr is oxidised (anode), Cd

^{2 +}

reduced (cathode); electrons exchanged

n = 6

E_{ce l l}^{\circ} = - 0.40 - (- 0.74)

E_{ce l l}^{\circ} = 0.34 V

Δ G^{\circ} = - n F E_{ce l l}^{\circ} = - 6 \times 96500 \times 0.34

Δ G^{\circ} = - 1.97 \times 1 0^{5} J = - 196.9 kJ mo l^{- 1}

CBSE Class 12 Board · 2007 · All India · Subjective