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

Options

A. `(2)/(3) " mol of "MnO_(4)^(ɵ) and (1)/(3) " mol of "MnO_(2)`
B. `(1)/(3) " mol of "MnO_(4)^(ɵ) and (2)/(3) " mol of "MnO_(2)`
C. `(1)/(3) " mol of "Mn_(2)O_(7) and (2)/(3) " mol of "MnO_(2)`
D. `(2)/(3) " mol of "Mn_(2)O_(7) and (1)/(3) " mol of "MnO_(2)`

Answer

A

Explanation

Remember it as fact: in nautral medium `K_(2)MnO_(4)` (potassium manganate) disproportionate as follows:
`K_(2)MnO_(4)toKMnO_(4)+MnO_(2)`
On balancing we get:
`3MnO_(4)^(2-)+2H_(2)Oto2MnO_(4)^(ɵ)-=(1)/(3)molMnO_(2)`