Q. Which do not decolourise ${KMnO}_{4}$ aqueous solution?
A) $C_{2}O_{4}^{2 -}$
B) ${HSO}_{3}^{-}$
C) ${CO}_{3}^{2 -}$
D) ${SO}_{3}^{2 -}$
Explanation
(c)
Potassium permanganate is a powerful oxidizing agent in neutral, alkaline or acidic solution because it liberates nascent oxygen. The aqueous solutions of ${KMnO}_{4}$ can be decolourized by ${C_{2}O}_{4}^{2 -}$, ${HSO}_{3}^{-}$ and ${SO}_{3}^{2 -}$ while ${CO}_{3}^{2 -}$ cannot decolourise ${KMnO}_{4}$ aqueous solution.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.