Question

$MnO _{4}^{2-}(1 mole )$ in neutral aqueous medium is disproportionated to

• A. $2 / 3$ mole of $MnO _{4}^{-}$ and $1 / 3$ mole of $MnO _{2}$
• B. $1 / 3 molc$ of $MnO _{4}^{-}$ and $2 / 3 mole$ of $MnO _{2}$
• C. $1 / 3$ molc of $Mn _{2} O$, and $1 / 3$ mole of $MnO _{2}$
• D. $2 / 3$ molc of $Mn _{2} O _{7}$ and $1 / 3 mole$ of $MnO _{2}$.

Answer 1

Answer: (A)

$2 / 3$ mole of $MnO _{4}^{-}$ and $1 / 3$ mole of $MnO _{2}$

Answer 2

${3MnO4^{2-} + 2H2O -> MnO_{2 (s)} + 2MnO4^{-} + 4OH^{-}}$ for one mole ${MnO4^{2-} + \frac{2}{3} H2O -> \frac{1}{3}MnO_{2 (s)} + \frac{2}{3} MnO4^- + \frac{4}{3} OH^- }$