Standard reduction potentials at : Using these data

CHEMISTRY · Single correct · A Level · Chemistry · Electrode potentials · Electrode potentials

Problem

Standard reduction potentials at

25^{\circ}\text{C}

\text{O}_2(g) + 4\text{H}^+(aq) + 4e^- \rightarrow 2\text{H}_2\text{O}(l)\quad E^{\circ} = +1.23\,\text{V}

\text{Fe}^{3+}(aq) + e^- \rightarrow \text{Fe}^{2+}(aq)\quad E^{\circ} = +0.77\,\text{V}

Using these data, determine

\Delta G^{\circ}

(in kJ) for the overall reaction

\text{O}_2(g) + 4\text{H}^+(aq) + 4\text{Fe}^{2+}(aq) \rightarrow 4\text{Fe}^{3+}(aq) + 2\text{H}_2\text{O}(l)

(Assume

F = 9.65 \times 10^{4}\,\text{C mol}^{-1}

.) (a)

+1.78 \times 10^{2}\,\text{kJ}

(b)

-8.9 \times 10^{1}\,\text{kJ}

(c)

-1.78 \times 10^{2}\,\text{kJ}

(d)

-7.72 \times 10^{2}\,\text{kJ}