Chemistry - Electrochemistry Question with Solution | TestHub

Efficiency of the following cells is 84%.
$\mathrm{A}\left(\mathrm{s}\right)+{\mathrm{B}}^{2+}\left(\mathrm{a}\mathrm{q}\right)\rightleftharpoons {\mathrm{A}}^{2+}\left(\mathrm{a}\mathrm{q}\right)+\mathrm{B}\left(\mathrm{s}\right)$;$\mathrm{\Delta }\mathrm{H}=-285$kJ
Then the standard electrode potential of the cell will be