pBlock ElementsII 1 Question 93
89. Give reasons in two or three sentences only. Sulphur dioxide is a more powerful reducing agent in the alkaline medium than in acidic medium.
(1992, 2M)
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Solution:
- $\mathrm{SO}_{2}$ acts as reducing agent on account of following reaction :
$$ \mathrm{SO}{2}+2 \mathrm{OH}^{-} \longrightarrow \mathrm{SO}{4}^{2-}+2 \mathrm{H}^{+}+2 e^{-} $$
Hence, the above reaction proceeds in forward direction on increasing concentration of $\mathrm{HO}^{-}$ion. $\mathrm{H}^{+}$is on product side, adding $\mathrm{H}^{+}$retards the reaction by sending it in backward direction.
