Number of moles of H ^ + ions required by 1 mole of MnO _ 4 ^ - to...

The reaction between ${MnO}_{4}^{-}$ with ${C}_{2}{O}_{4}^{2 -}$ is as given below:

$2{MnO}_{4}^{-} + 16{H}^{+} + 5{C}_{2}{O}_{4}^{2 -} \to 2{Mn}^{+ 2} + 8{H}_{2}O + 10{CO}_{2}$

From this, we can see that $16$ moles of ${H}^{+}$react with $2$ moles of ${MnO}_{4}^{-}$ .  Hence, one mole of permanganate requires eight moles of ${H}^{+}$ ions