Consider the following reduction processes: Zn^2++2 e^- → Zn ( s ); E^°=-0.76 V; Ca^2++2 e^- → Ca ( s ); E^°=-2.87 V; Mg^2++2 e^- → Mg ( s );…

Consider the following reduction processes : $$\begin{aligned} & \mathrm{Zn}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}(\mathrm{~s}) ; \mathrm{E}^{\circ}=-0.76 \mathrm{~V} \\ & \mathrm{Ca}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ca}(\mathrm{~s}) ; \mathrm{E}^{\circ}=-2.87 \mathrm{~V} \\ & \mathrm{Mg}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Mg}(\mathrm{~s}) ; \mathrm{E}^{\circ}=-2.36 \mathrm{~V} \\ & \mathrm{Ni}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ni}(\mathrm{~s}) ; \mathrm{E}^{\circ}=-0.25 \mathrm{~V} \end{aligned} $$ The reducing power of the metals increases in the order: