$\Delta G$ is negative, if $E _{\text {cell }}$ is positive
Anode : $\quad Cu ( s ) \longrightarrow Cu ^{-2}\left( C _{1}\right)+2 e ^{-}: E ^{\circ}$
$\frac{\text { Cathode }: Cu ^{+2}\left( C _{2}\right)+2 e ^{-} \longrightarrow Cu ( S ):- E ^{\circ}}{\text { Cell reaction }: Cu ^{+2}\left( C _{2}\right) \longrightarrow Cu ^{+2}\left( C _{1}\right) E _{\text {cell }}^{\circ}=0}$
$E _{\text {cell }}= E _{\text {cell }}^{\circ}-\frac{2.303 RT }{ nF } \log Q$
$E _{\text {cell }}=0-\frac{2.303 RT }{ nF } \log \left(\frac{ C _{1}}{ C _{2}}\right)$
$E _{\text {cell }}>0:$ if $\frac{ C _{1}}{ C _{2}}<1 \Rightarrow C _{1}< C _{2}$
$Zn = Z{n^{2 + }} + 2{e^ - };\,\,{E^o} = + 0.76\,V$
$Fe = F{e^{2 + }} + 2{e^ - };\,\,{E^o} = + 0.41\,V$
નીચેના કોષ પ્રક્રિયા માટે $EMF$ ......... $\mathrm{V}$ છે
$F{e^{2 + }} + Zn\, \to \,Z{n^{2 + }} + Fe$
$E.C.E\, Zn=32.5\,, \,E.C.E \,Cu=31.5)$
જો $\Lambda_{{m}}^{\circ}$ $({HA})=190 \,{~S} \,{~cm}^{2} {~mol}^{-1}$, ${HA}$નો આયનીકરણ અચળાંક $\left({K}_{{a}}\right)$ $....\,\times 10^{-6}$ બરાબર છે.
$Fe_{(aq)}^{3 + } + {e^ - } \to Fe_{(aq)}^{2 + }$ ; ${E^o} = 0.771{\mkern 1mu} \,volts;{\mkern 1mu} $
${\mkern 1mu} {I_{2(g)}} + 2{e^ - } \to 2I_{(aq)}^ - \,;{\mkern 1mu} $ ${E^o} = 0.536{\mkern 1mu} \,volts$
કોષ પક્રિયા $2Fe^{3+}_{(aq)} + 2l^{-}_{(aq)} \rightarrow 2Fe^{2+}_{(aq)} + I_{2(g)}$ માટે $E^o_{cell} = ….$