For the given cell
Fe2+(aq)+Ag+(aq)→Fe3+(aq)+Ag(s)
The standard cell potential of the above reaction is:
Given:
Ag++e-→Ag Eθ=x V
Fe2++2e-→Fe Eθ=y V
Fe3++3e-→Fe Eθ=z V [2025]
(1)
Ag++e-→Ag-I (ΔG1=-nFE1=-1Fx)
Fe2++2e-→Fe-II (ΔG2=-nFE2=-2Fy)
Fe3++3e-→Fe-III (ΔG3=-nFE3=-3Fz)
I+II-III gives the required equation:
Fe2++Ag+→Fe3++Ag-IV
ΔG4=ΔG1+ΔG2-ΔG3=-1Fx- 2Fy+3Fz
-nFE4=-1Fx-2Fy+3Fz
-IFE4=-1Fx-2Fy+3Fz
E4=x+2y-3z