\(\mathrm{Sn}(\mathrm{s})+\mathrm{Pb}^{+2}(\mathrm{aq}) \rightarrow \mathrm{Sn}^{+2}(\mathrm{aq})+\mathrm{Pb}(\mathrm{s})\dots (1)\)

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 \(( 1)\)

\(0=0.01-\frac{0.06}{2} \log \frac{\left[\mathrm{Sn}^{+2}\right]}{\left[\mathrm{Pb}^{+2}\right]}\)

\(\Rightarrow \quad \frac{1}{3}=\log \frac{\left[\mathrm{Sn}^{+2}\right]}{\left[\mathrm{Pb}^{+2}\right]}\)

\(\Rightarrow\; \frac{\left[\mathrm{Sn}^{+2}\right]}{\left\lceil\mathrm{Pb}^{+2}\right\rceil}=2.15\)