Four successive members of first row transition element are listed belw. Which one of them is expected to have highest `E_((M^(3+))/(M^(2+))^(ɵ)` value?

Options

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

Answer

C

Explanation

Simple compounds containing `Co(+3)` are oxidizing and are relatively unstable. However, `Co(+3)` is stable and is very impoertant in complexes.
`E_(Cr^(3+)//Cr^(2+))^(@) (-0.41 V)`, `E_(Mn^(3+)//Mn^(2+))^(@) (+1.57 V)`,
`E_(Fe^(3+)//Fe^(2+))^(@) (+0.77 V)`, `E_(Co^(3+)//Co^(2+))^(@) (+1.97 V)`