$2{H_2}_{(g)} + 4O{H^ - }_{(aq)} \to 4{H_2}{O_{(l)}} + 4{e^ - }$
$\underline {{O_2}_{(g)} + 2{H_2}{O_{(l)}} + 4{e^ - } \to 4O{H^ - }_{(aq)}} $
Overall reaction $=\,2{H_2}_{(g)} + {O_{2(g)}} \to 2{H_2}{O_{(l)}}$
the net reaction is the same as burning (Combustion) of hydrogen to form water.
$Zn(s)\, + \,C{u^{2 + }}(aq)\, \to \,Z{n^{2 + }}(aq) + Cu\,(s)$
$(298\,K$ પર ${E^o} = 2\,V,$ ફેરાડે અચળાંક $F = 96500\, C\, mol^{-1})$
($Cu$નું આણ્વિય દળ $63.5\, amu$)