In the extraction of chlorine from brine

Electrolysis of brine solution is used to extract chlorine. Overall chemical reaction occurring in this process and value of $∆{\mathrm{G}}^{\mathrm{o}}$ can be shown as
$2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+2{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)⟶{\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)+2{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)$
For the given reaction, value of ${\mathrm{\Delta G}}^{\circ }\text{ is }+422 \mathrm{kJ}$
Using ${\mathrm{\Delta G}}^{\circ }=-{\mathrm{nFE}}^{\mathrm{c}}$ the value of ${\mathrm{E}}^{\circ }=-2.2\mathrm{V}$.
Therefore,${\mathrm{\Delta G}}^{\circ }$for the overall reaction is positive and ${\mathrm{E}}^{\mathrm{o}}$has negative value.