Q.
To find the standard potential of $M^{3+}/M$ electrode, the following cell is constituted : $Pt/M/M^{3+} (0.001 \, mol \, L^{-1})/Ag^{+} (0.01 \, mol \, L^{-1}) /Ag$
The emf of the cell is found to be $0.421$ volt at $298\, K$. The standard potential of half reaction $M^{3+} + 3e^{-} \to M$ at 298 K will be :
(Given $E^{\ominus}_{Ag^{+} /Ag}$ at 298 K = 0.80 Volt)
Solution: