Q. Acidic solution of $S_{2}O_{3}^{2 -}$ is converted to ……… in presence of $I_{2}$
A) $S_{4}O_{6}^{2 -} + I^{-}$
B) $SO_{4}^{2 -} + I^{-}$
C) $SO_{3} + I^{-}$
D) $S_{4}O_{6}^{2 -} + I_{3}^{-}$
Explanation
(a)
Thiosulphate $(S_{2}O_{3}^{2 -})$ is oxidised to tetrathionate $(S_{4}O_{6}^{2 -})$ ion by iodine.
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {\ I}_{2} + 2S_{2}O_{3}^{2 -} \longrightarrow S_{4}O_{6}^{2 -} + 2I^{-}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.