The `E_(M^(3+)//M^(2+)^@` values for ` Cr`, Mn, Fe and ` Co` are ` 0.41, + 1.57 , + 0.77` and `+1, 97 V` respectively. For which one of these metals the change ub oxidation state from ` =2 ` to ` 3` is easiest :

Options

A. `Co`
B. `Mn`
C. `Fe` and `Au`
D. `Cr`

Answer

D

Explanation

More is `E_(RP)^(@)`, more is the tendency to get reduced or lesser is tendency to get oxidised. `E_(RP_(Cr^(3+)//Cr^(2+)))^(@)` is lowest or `E_(OP_(Cr^(2+)//Cr^(3+)))^(@)` is maximum among all.