Given below is the Gibbs free energy change ( $\Delta \mathrm{G}$ ) in kilo Joules per electron equivalent ( $\mathrm{kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}$ ) at pH $7.0$, of organic and inorganic half reactions.
Acetate synthesis:
\[
\frac{1}{8} \mathrm{CO}_{2}+\frac{1}{8} \mathrm{HCO}_{3}^{-}+\mathrm{H}^{+}+\mathrm{e}^{-} \rightarrow \frac{1}{8} \mathrm{CH}_{3} \mathrm{COO}^{-}+\frac{3}{8} \mathrm{H}_{2} \mathrm{O} \quad \Delta \mathrm{G}=27.4 \mathrm{~kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}
\]
Reduction reaction:
\[
\frac{1}{4} \mathrm{O}_{2}+\mathrm{H}^{+}+\mathrm{e}^{-} \rightarrow \frac{1}{2} \mathrm{H}_{2} \mathrm{O} \quad \Delta \mathrm{G}=-78.72\mathrm{~kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}
\]
The free energy change of acetate oxidation to $\mathrm{CO}_{2}, \mathrm{H}_{2} \mathrm{O}$ and $\mathrm{HCO}_{3}^{-}$ is $\_\_\_\_$ $\mathrm{kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}$. (rounded off to two decimal places)
