Given the standard electrode reduction potentials: , and , . Which of the following statements are C — Electrochemistry Chemistry Question
Question
Given the standard electrode reduction potentials: $Fe^{3+}(aq) + 3e^- \rightarrow Fe(s)$, $E^\circ = -0.036\text{ V}$ and $Fe^{2+}(aq) + 2e^- \rightarrow Fe(s)$, $E^\circ = -0.440\text{ V}$. Which of the following statements are CORRECT?
💡 Solution & Explanation
For option A: $\Delta G_3^\circ = \Delta G_1^\circ - \Delta G_2^\circ = -3F(-0.036) - [-2F(-0.440)] = +0.108F - 0.880F = -0.772F$. Since $\Delta G_3^\circ = -1F E^\circ_3$, $E^\circ_3 = +0.772\text{ V}$. Option B: $\Delta G_1^\circ = +0.108 \times 96500 = 10422\text{ J/mol} = 10.422\text{ kJ/mol}$. Option C: Disproportionation EMF is $E^\circ = -0.440 - 0.772 = -1.212\text{ V}$ (non-spontaneous). Option D: Intensive properties do not depend on the amount of substance and cannot be added directly; $\Delta G$ must be used instead.