Which of the following relations about $\mathrm{E}_{\text {cell }}^{\circ}$ is false?

For cell reaction,

$$ 2 \mathrm{Al}_{(\mathrm{s})}+3 \mathrm{Cu}_{(\mathrm{aq})}^{+2} \longrightarrow 2 \mathrm{Al}_{(\mathrm{aq})}^{+3}+3 \mathrm{Cu}_{(\mathrm{s})} $$

If $\Delta \mathrm{G}^{\circ}=-1158 \mathrm{~kJ}$, what is $\mathrm{E}_{\text {cell }}^{\circ}$?

If $\mathrm{E}^*\left(\mathrm{Mg}^{+2}{ }_{(\mathrm{aq})} \mid \mathrm{Mg}_{(\mathrm{s})}\right)=-2.37 \mathrm{~V}$.

What is potential for $\mathrm{Mg}_{(\mathrm{s})} \rightarrow \mathrm{Mg}^{+2}(0.1 \mathrm{M})+2 \mathrm{e^-}$ at 298 K ?