In presence of fluoride ion `Mn^(2+)` can be titrated with `MnO_(4)^(-)` both reactants being converted to a complex of `Mn(II)` in presence of `F^(-)` ions. A `0.545 g` of sample containing `Mn_(3)O_(4)` was dissolved and all manganese was converted to `Mn^(2+)`. The titration in presence of fluoride ion consumed `31.1 mL` of `KMnO_(4)` that was `0.117 N` against oxalate.
(a) Write balanced chemical equation of titration was assuming that the complex is `MnF_(4)^(-)`.
(b) What was the `%` of `Mn_(3)O_(4)` in sample?

Answer

(b) `40.734%`