Among the following, which order is correct regarding the stability of oxidation state ?

Options

A. `Ni^(2+) gt Pt^(2+)`
B. `Cr^(2+) lt Cr^(3+)`
C. `Mn^(2+) gt Mn^(3+)`
D. All of these

Answer

D

Explanation

Stability of `Ni^(2+)` is more than that of `Pt^(+2)` because ionisation energy of platinum is more than that of nickel due to which energy content of platinum is more than that of nickel after formation of cation.
Electrons in `t_(2g)` orbital is half filled in `Cr^(+3)` ion which is relatively more stable than electronic configuration in `Cr^(+2)` ion. `Mn^(2+)` has half filled electronic configuration which is quite stable than `Mn^(3+)`