Four successive members of the first row transition elements are listed below with atomic numbers. Which one of them is expected to have the highest `E_(M^(3+)|M^(2+))^(0)` value -

Options

A. Cr (Z = 24)
B. Mn (Z = 25)
C. Fe (Z = 26)
D. Co (Z = 27)

Answer

D

Explanation

`E_(Cr^(3+)|Cr^(2+))^(0)=-0.41V , E_(Mn^(3+)|Mn^(2+))^(0)=+1.57V`,
`E_(Fe^(3+)|Fe^(2+))^(0)=+0.77V , E_(Co^(3+)|Co^(2+))^(0)=+1.97V`, Standard reduction potential of `Co^(3+)|Co^(2+)` system is higher due to exceptional stability of the product ion.