In neutral or alkaline solution, $\mathrm{MnO}_{4}^{-}$ oxidises thiosulphate to:

(A) $\mathrm{S}_{2} \mathrm{O}_{7}^{2-}$

(B) $\mathrm{S}_{2} \mathrm{O}_{8}^{2-}$

JEE Main · 2022 · 27 Jul 2022 · Shift 2 · d and f Block Elements

In neutral or alkaline solution,

MnO_{4}^{-}

oxidises thiosulphate to:

Answer: (D)

In neutral or alkaline solution, permanganate ion (

MnO_{4}^{-}

) is a weaker oxidizing agent compared to acidic medium. It oxidizes thiosulphate (

S_{2} O_{3}^{2 -}

) completely to sulphate (

SO_{4}^{2 -}

).

The balanced equation is:

8 MnO_{4}^{-} + 3 S_{2} O_{3}^{2 -} + H_{2} O \to 8 MnO_{2} + 6 SO_{4}^{2 -} + 2 OH^{-}

Therefore, the product is

SO_{4}^{2 -}

JEE Main · 2022 · 27 Jul 2022 · Shift 2 · Single correct option