Question

Reaction of phenylacetylene with $dil.H_{2}S{O}_4$ and $HgS{O}_4$ gives

• A. acetophenone
• B. 2-phenylethenol
• C. phenylacetaldehyde
• D. phenylacetic acid

Answer 1

The correct option is A acetophenone

Alkynes react with water in the presence of dilute sulphuric acid and mercuric sulphate at a temperature of 333K. This results in the formation of carbonyl compounds through a keto-enol tautomerization of the more substituted enol.
Acid-catalyzed hydration of internal alkynes can produce one or two ketones depending if the alkyne is symmetrical or not. And terminal alkynes produce only one ketone following the Markovnikov’s rule. Hence the correct option is (a).
Hence, Reaction of phenylacetylene with $dil.H_{2}S{O}_4$ and $HgS{O}_4$ gives acetophenone.