Question

$KMnO _{4}$ oxidises $S _{2} O _{3}^{2-}$ to $SO _{4}^{2-}$ in medium $x$ and $NO^{-}_2$ to $NO^{-}_3$ in medium $y, x$ and $y$ are respectively

• A. acidic, basic
• B. acidic, acidic
• C. acidic, neutral
• D. neutral, acidic

Answer 1

Answer: (D)

neutral, acidic

Answer 2

In neutral or faintly alkaline solution. $8 MnO _{4}^{-}+3 S _{2} O _{3}^{-2}+ H _{2} O \longrightarrow 8 MnO _{2} +6 SO _{4}^{-2}+2 OH ^{-}$ In acidic medium, $2 MnO _{4}^{-}+5 NO _{2}^{-}+6 H ^{+} \longrightarrow 2 Mn ^{+2}+5 NO _{3}^{-}+3 H _{2} O$