Hydrocarbons - Result Question 51
####36. Which of the following will decolourise alkaline $KMnO _4$ solution?
(1980, 1M)
(a) $C _3 H _8$
(b) $CH _4$
(c) $CCl _4$
(d) $C _2 H _4$
Objective Questions II
(One or more than one correct option)
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Answer:
Correct Answer: 36. (d)
Solution:
- Unsaturated compounds which contain $C=C$ or $C \equiv C$, decolourises the purple colour of alkaline $KMnO _4$ solution.
$$ CH _2=CH _2+\underset{\substack{\text { purple } \ \text { coloured }}}{KMnO _4} \xrightarrow{HO^{-}} \underset{CH _2-OH}{CH _2-OH}+MnO _2 \downarrow $$
