Identify the oxidation states of Mn when `MnO_3^(3-)` ion undergoes disproportionation reaction under acidic medium

Options

A. `+2,+7`
B. `+2,+5`
C. `+4,+4`
D. `+7,+4`

Answer

D

Explanation

Given,
`MnO_4^(2-)` ion undergoes disporportionation reaction under acidic medium
`underset(+6)(3MnO_4^(2-)) + 4H+ to underset(+4)(MnO_2^-) + underset(+7) (2MnO_4^-)+ 2H_2O`
`MnO_4^(2-)` is oxidized to `MnO_2` and reduced to `MnO_2`
` therefore` The oxidation states of Mn are +7 and +4.