Given that and that calculate ?G°for the following

QUESTION:

Given that \(\Delta G_{\mathrm{f}}^{\circ}\left(\mathrm{Fe}_2\mathrm{O}_3\right)=-741.0\mathrm{\ kJ}/\mathrm{mol}\) and that \(\Delta G_{\mathrm{f}}^{\circ}\left(\mathrm{Al}_2\mathrm{O}_3\right)=-1576.4\mathrm{\ kJ}/\mathrm{mol}\), calculate \(\Delta G^{\circ}\) for the following reactions at \(25^{\circ} \mathrm{C}\):

(a) \(2\mathrm{Fe}_2\mathrm{O}_3(s)\ \longrightarrow\ 4\mathrm{Fe}(s)+3\mathrm{O}_2(g)\)

(b) \(2\mathrm{Al}_2\mathrm{O}_3(s)\ \longrightarrow\ 4\mathrm{Al}(s)+3\mathrm{O}_2(g)\)