$H_3PO_4 + OH^- \rightarrow H_2PO_4^- + H_2O$ ;
$H_3PO_4 + 2OH^- \rightarrow HPO_4^{2-} + 2H_2O$ ;
$H_3PO_4 + 3OH^- \rightarrow PO_4^{3-} + 3H_2O$
$E.C.E\, Zn=32.5\,, \,E.C.E \,Cu=31.5)$
$(i)\, A3^-\rightarrow A^{2-} + e; E° = 1.5 \,V$
$(ii) \,B^{+}+ e \rightarrow B; E° = 0.5 \,V$
$(iii)\, C^{2+} + e \rightarrow C^{+}; E°= 0.5\, V$
$(iv)\, D \rightarrow D^{2+}+ 2e; E° = -1.15\, V$
$Cu(s) + 2Ag{^+}_{(aq)} \to Cu^{+2}_{(aq)} + 2Ag(s)$
માટે સંતુલન અચળાંક $K_C = 10 \times 10^{15}$ છે, તો $298\, K$ ને $E_{cell}^o$ નું મૂલ્ય કેટલુ થશે?
[${2.303\,\frac{{RT}}{F}}$ એ $298\,K$ $=0.059\,V$]