Peroxydisulphate oxidises manganese(II) in water: S2O8^2- + Mn^2+ + H2O -> MnO4^- + SO4^2- + H^+. In the balanced equation, the number of moles of H^+ produced per mole of Mn^2+ oxidised is

JEE Advanced levelSingle correct optionDifficulty 3 of 3rx070

Peroxydisulphate oxidises manganese(II) in water: $S X_{2} O X_{8} X^{2 -} + Mn X^{2 +} + H X_{2} O MnO X_{4} X^{-} + SO X_{4} X^{2 -} + H X^{+}$ . In the balanced equation, the number of moles of $H X^{+}$ produced per mole of $Mn X^{2 +}$ oxidised is

Mn goes +2 to +7 (5 electrons). In

S X_{2} O X_{8} X^{2 -}

the S stays +6; the two peroxide O atoms go from -1 to -2, so each

S X_{2} O X_{8} X^{2 -}

gains 2 electrons. Hence 5

S X_{2} O X_{8} X^{2 -}

: 2

Mn X^{2 +}

, and the balanced equation is

5 S X_{2} O X_{8} X^{2 -} + 2 Mn X^{2 +} + 8 H X_{2} O 2 MnO X_{4} X^{-} + 10 SO X_{4} X^{2 -} + 16 H X^{+}

, giving 16/2 = 8

H X^{+}

per

Mn X^{2 +}