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NEET CHEMISTRYHydrocarbonsMedium

Question

The compound obtained by addition of water to an alkyne having more than two carbons, in the presence of HgSO4\text{HgSO}_4 and dilute H2SO4\text{H}_2\text{SO}_4 at 333 K333\text{ K}, is:

A

A vicinal diol

B

An aldehyde

C

An alcohol

D

A ketone

Step-by-Step Solution

Alkynes undergo hydration when warmed with water in the presence of mercuric sulphate (HgSO4\text{HgSO}_4) and dilute sulphuric acid (H2SO4\text{H}_2\text{SO}_4) at 333 K333\text{ K} to form carbonyl compounds. The addition of water follows Markovnikov's rule. While the hydration of ethyne (a 2-carbon alkyne) yields ethanal (an aldehyde), the hydration of any higher alkyne having more than two carbon atoms (such as propyne, but-1-yne, etc.) yields a ketone. This happens because the nucleophile (OH−\text{OH}^- from water) attaches to the more substituted carbon atom of the triple bond, forming an unstable enol intermediate, which then tautomerizes to form a stable ketone .

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Hydrocarbons. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYHydrocarbonscompoundobtainedadditionalkynehaving

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A.Option 1 (Structure missing)
B.Option 2 (Structure missing)
C.Option 3 (Structure missing)
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A.(Option 1 Structure Missing)
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C.4
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