## Chemistry: The Molecular Science (5th Edition)

The reaction is product-favored. Up to $1484\,kJ/mol$ useful work can be done.
$\Delta_{r}G^{\circ}=\Sigma n_{p}\Delta_{f}G^{\circ}(products)-\Sigma n_{r}\Delta_{f}G^{\circ}(reactants)$ $=[2\Delta_{f}G^{\circ}(Fe_{2}O_{3},s)]-[4\Delta_{f}G^{\circ}(Fe,s)+3\Delta_{f}G^{\circ}(O_{2},g)]$ $=[2(-742.2\,kJ/mol)]-[4(0\,kJ/mol)+3(0\,kJ/mol)]$ $=-1484\,kJ/mol$ $\Delta_{r}G^{\circ}$ is negative. Therefore, the reaction is product-favored. Up to $1484\,kJ/mol$ useful work can be done.