Zinc reduces iron(III) ions: $\text{Zn}(s) + 2\text{Fe}^{3+}(aq) \rightarrow \text{Zn}^{2+}(aq) + 2\text{Fe}^{2+}(aq)$. Use $E^\circ(\text{Zn}^{2+}/\text{Zn}) = -0.76\ \text{V}$ and $E^\circ(\text{Fe}^{3+}/\text{Fe}^{2+}) = 0.77\ \text{V}$. What is $\Delta G^\circ$ for this reaction?