`MnO_(4)^(2-)` (1 mole) in neutral aqueous medium disproportionates 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_(2)O_(7) and 1//3 ` mole of `MnO_(2)`
D. 2/3 mole of `Mn_(2)O_(7) and 1//3` mole of `MnO_(2)`

Answer

A

Explanation

`3MnO_(4)^(2)+2H_(2)O to MnO_(2)+2MnO_(4)^(-)+4OH^(-)`
or `MnO_(4)^(2-)+(2)/(3)H_(2)O to (1)/(3)MnO_(2)+(2)/(3)MnO_(4)^(-)+(4)/(3)OH^(-)`