= Solution
For the $x=1$ reaction there is one <mole> of transferred <electrons> per <mole> of reaction. \b[Treating the supplied fresh-cell <open-circuit voltage> as the standard equilibrium cell potential] gives
$$
\boxed{\Delta G^\circ=-FE^\circ=-(96500)(4.57)=-441005\,\mathrm{J\,mol^{-1}}
\simeq-441\,\mathrm{kJ\,mol^{-1}}}.
$$
A fresh-cell <voltage> alone would not normally establish standard conditions or equilibrium. The result above is the formal standard-free-energy estimate under the interpretation required to use the given datum; a metastable <open-circuit voltage> should not be mistaken for an independently measured standard thermodynamic potential.
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