$(i)$ $Zn| Zn^{2+} {(1\,M)}|| Cu^{2+}{(0.1\,M)}| Cu$
$(ii)$ $Zn| Zn^{2+} {(1\,M)}|| Cu^{2+}(1\,M) |Cu $
$(iii)$ $Zn| Zn^{2+} {(0.1\,M)}|| Cu^{2+}{(1\,M)}| Cu$
જેમ \(log [Zn^{2+}]/[Cu^{2+}]\) નું મૂલ્ય જેમ વધુ તેમ \(E\) નું મૂલ્ય ઓછું.
\({\text{(i)}}\,\,{\text{log }}\left[ {\frac{{{\text{Z}}{{\text{n}}^{{\text{2 + }}}}}}{{{\text{C}}{{\text{u}}^{{\text{2 + }}}}}}} \right] = 10;\,\,\,\,\,\,(ii)\,\,{\text{log }}\left[ {\frac{{{\text{Z}}{{\text{n}}^{{\text{2 + }}}}}}{{{\text{C}}{{\text{u}}^{{\text{2 + }}}}}}} \right]\)\( = 1;\,\,\)
\(\,(iii)\,\,{\text{log }}\left[ {\frac{{{\text{Z}}{{\text{n}}^{{\text{2 + }}}}}}{{{\text{C}}{{\text{u}}^{{\text{2 + }}}}}}} \right] = 0.1\,\,\,\,\,\,\,\therefore \,\,\,\,{E_3} > {E_2} > {E_1}\)
$Zn^{2+}(aq) + 2e^{-} $ $\rightleftharpoons$ $ Zn (s)$ , $E^o_{RP}= -0.762\, V$,
$Cr^{3+}(aq) + 3e^{-} $ $\rightleftharpoons$$ Cr(s)$, $E^o_{RP} = -0.740\, V$
$2H^{+}(aq) + 2e^{-} $$\rightleftharpoons$$ H_2(g)$, $E^o_{RP} = 0.00\,V$,
$Fe^{3+}_{(aq)} + 2e^{-} $$\rightleftharpoons$$ Fe^{2+}(aq)$ , $E^o_{RP} = 0.77 \,V$
$Zn | Zn ^{2+}(0.1\, M ) \| Ag ^{+}(0.01 \,M )| Ag$
[આપેલ $: E_{Z n^{+2}/Z_{n}}^{0}=-0.76 \,V ; E _{A g^{+} / A_{ g }}^{0}=+0.80 \,V ; \frac{2.303 RT }{ F }=0.059$]
${{\text{E}}^o }{\text{C}}{{\text{u}}^{{\text{2}} + }}{\text{/Cu = + 0}}{\text{.34 V, E}}_{{\text{F}}{{\text{e}}^{ + {\text{2}}}}/Fe}^o = \,\,{\text{ - 0}}{\text{.44 V}}$