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In the dehydration of alcohols to alkenes by heating with concentrated sulphuric acid, the…
In the dehydration of alcohols to alkenes by heating with concentrated sulphuric acid, the initiation step is:
- (1)formation of carbocation
- (2)formation of an ester
- (3)protonation of alcohol molecule
- (4)elimination of water
Answer
Answer
AICorrect option: (3)
Answer: (3) protonation of alcohol molecule
The first step is the protonation of the alcohol by $\mathrm{H_2SO_4}$ to form an oxonium ion; loss of water then gives the carbocation.
From ISC 2018 Chemistry Paper 1, question 1(b)(iv).