`MnO_(4)^(2-)` (`1` mole) in neutral aqueous medium is disproportionate to

Options

A. 2/3 mole of `MnO_4^-` and 1/3 mole of `MnO_2`
B. 1/3 mole of `MnO_4^-` and 2/3 mole of `MnO_2`
C. 1/3 mole of `Mn_2O_7` and 1/3 mole of `MnO_2`
D. 2/3 mole of `Mn_2O_7` and 1/3 mole of `MnO_2`

Answer

A

Explanation

`3MnO_4^(2-) + 2H_2O to MnO_(2(s)) + 2MnO_4^(-) + 4OH^-`
For one mole
`MnO_4^(2-) + 2/3H_2O to 1/3 MnO_(2(s)) + 2/3 MnO_4^(-) + 4/3OH^-`