(આપેલ છે: $\mathrm{E}_{\mathrm{Sn}^{2+} / \mathrm{Sn}}^{0}=-0.14 \mathrm{\;V}$ $\left.\mathrm{E}_{\mathrm{Pb}^{+2}/{\mathrm{Pb}}}^{0}=-0.13 \;\mathrm{V}, \frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.06\right)$
\(\mathrm{Sn}(\mathrm{s})+\mathrm{Pb}^{+2}(\mathrm{aq}) \rightarrow \mathrm{Sn}^{+2}(\mathrm{aq})+\mathrm{Pb}(\mathrm{s})\dots (1)\)
Apply Nernst equation:
\(\mathrm{E}_{\text {cell}}=\mathrm{E}_{\text {cel }}^{0}-\frac{0.06}{2} \log \frac{\left[\mathrm{Sn}^{+2}\right]}{\left[\mathrm{Pb}^{+2}\right]}\)
\(\mathrm{E}_{\mathrm{cell}}^{0}=-0.13+0.14=0.01 \mathrm{V}\)
At equilibrium : \(E_{\text {cell}}=0\)
Substituting in \(( 1)\)
\(0=0.01-\frac{0.06}{2} \log \frac{\left[\mathrm{Sn}^{+2}\right]}{\left[\mathrm{Pb}^{+2}\right]}\)
\(\Rightarrow \quad \frac{1}{3}=\log \frac{\left[\mathrm{Sn}^{+2}\right]}{\left[\mathrm{Pb}^{+2}\right]}\)
\(\Rightarrow\; \frac{\left[\mathrm{Sn}^{+2}\right]}{\left\lceil\mathrm{Pb}^{+2}\right\rceil}=2.15\)
[આપેલ, $KCl$ નું મોલર દળ $74.5 \,g\, mol ^{-1}$ છે.]
$Cr\, | \,Cr^{3+}_{(0.1\,M)}\,||\, Fe^{2+}_{(0.01\, M)}\,|\, Fe$