If standard reduction potential $\left(\mathrm{E}^{\circ}\right)$ of $\left(\mathrm{Mg}_{(\mathrm{aq})}^{+2} \mid \mathrm{Mg}_{(\mathrm{s})}\right),\left(\mathrm{Ag}_{(\mathrm{aq})}^{+} \mid \mathrm{Ag}_{(\mathrm{s})}\right),\left(\mathrm{Zn}^{+2}{ }_{(\mathrm{aq})} \mid \mathrm{Zn}_{(\mathrm{s})}\right)$ and $\left(\mathrm{Cu}^{+2}{ }_{(\text {aq })} \mid \mathrm{Cu}_{(\text {s })}\right)$ are $-2.37 \mathrm{~V},+0.79 \mathrm{~V},-0.76 \mathrm{~V}$ and +0.34 V respectively. Which of the following reaction is spontaneous?

What is molar conductivity at zero concentration in $\Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ for aluminium sulphate, if molar ionic conductivities at zero concentration of $\mathrm{Al}^{+3}$ and $\mathrm{SO}_4^{-2}$ are $189 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ and $50.1 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ respectively?

For the cell involving following reaction.

$$ \mathrm{Zn}_{(\mathrm{s})}+\mathrm{Ni}_{(\mathrm{aq})}^{+2} \longrightarrow \mathrm{Zn}_{(\mathrm{aq})}^{+2}+\mathrm{Ni}_{(\mathrm{s})}, \mathrm{E}_{\mathrm{cell}}^*=0.5 \mathrm{~V} . $$

What is standard Gibb's energy change of cell reaction?

If $\mathrm{E}^{\circ}\left(\mathrm{Zn}_{(\mathrm{aq})}^{+2} \mid \mathrm{Zn}_{(\mathrm{s})}\right)=-0.76 \mathrm{~V}$.

Calculate potential for $\mathrm{Zn}_{(\mathrm{s})} \rightarrow \mathrm{Zn}^{+2}(0.01 \mathrm{M})+2 \mathrm{e}^{-}$at 298 K .