For (M^(2+))/(M) and (M^(3+))/(M^(2+)) systems the E^(ɵ) values for some metals are as follows. (Cr^(2+))/(Cr) -0.9V, (Cr^(3+))/(Cr^(2+)) -0.4V (Mn^(2+))/(Mn)-1.2V,(Mn^(3+))/(Mn^(2+)) +1.5V (Fe^(2+))/(Fe) -0.4, (Fe^(3+))/(Fe^(2+)) +0.8V Use this data comment upon: (i). The stability of Fe^(3+) in acid solutio as compared to that of Cr^(3+) or Mn^(3+) and ltbtgt (ii). The case with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.

For (M^(2+))/(M) and (M^(3+))/(M^(2+)) systems the E^(ɵ) values for s

1.	For (M^(2+))/(M) and (M^(3+))/(M^(2+)) systems the E^(ɵ) values for some metals are as follows. (Cr^(2+))/(Cr) -0.9V, (Cr^(3+))/(Cr^(2+)) -0.4V (Mn^(2+))/(Mn)-1.2V,(Mn^(3+))/(Mn^(2+)) +1.5V (Fe^(2+))/(Fe) -0.4, (Fe^(3+))/(Fe^(2+)) +0.8V Use this data comment upon: (i). The stability of Fe^(3+) in acid solutio as compared to that of Cr^(3+) or Mn^(3+) and ltbtgt (ii). The case with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.
Answer» Solution :(i). `((Cr^(3+))/(Cr^(2+)))` has a negative reduction potential. HENCE, `Cr^(3+)` cannot be reduced to `Cr^(2+)`, i.E., `Cr^(3+)` is most stable. `((Mn^(3+))/(Mn^(2+)))` has LARGE positive `E^(ɵ)` value for `((FE^(3+))/(Fe^(2+)))` is positive but small. Hence, `Fe^(3+)` is more stable than `Mn^(3+)` but less stable than `Cr^(3+)`. (ii). Oxidation potential for the given pairs will be `+0.9V,+1.2V` and `+0.4volt`. Thus, the order of their getting oxidised will be in the order `MngtCrgtFe`.