MnO₄²⁻ (1 mole) in neutral aqueous medium is disproportionated to

Options

(a) 2/3 mole of MnO₄⁻ and 1/3 mole of MnO₂
(b) 1/3 mole of MnO₄⁻ and 2/3 mole of MnO₂
(c) 1/3 mole of Mn₂O₇ and 1/3 mole of MnO₂
(d) 2/3 mole of Mn₂O₇ and 1/3 mole of MnO₂

Correct Answer:

2/3 mole of MnO₄⁻ and 1/3 mole of MnO₂

Explanation:

3MnO₄⁻² + 2H₂O →MnO₂(s) + 2MnO₄⁻ +4OH⁻
for one mole
MnO₄⁻² +2/3 H₂O →1/3 MnO₂(s) + 2/3 MnO₄⁻ + 4/3 OH⁻.