Exams › JEE Main › Chemistry

In the hydration of propyne, CH3–C≡CH, using H2O in the presence of H2SO4/HgSO4, which intermediate (A) and final product (B) are formed?

1. A: CH3–C(OH)=CH2; B: CH3–C(=O)–CH3
2. A: CH3–C(=O)–CH3; B: CH3–C≡CH
3. A: CH3–C(OH)=CH2; B: CH3–C(=O)–CH3
4. A: CH3–C(=CH2)SO4; B: CH3–C(=O)–CH3

Correct answer: A: CH3–C(OH)=CH2; B: CH3–C(=O)–CH3

Solution

Hydration of propyne in the presence of H2SO4/HgSO4 follows Markovnikov addition to give an enol intermediate. This enol rapidly tautomerizes to the more stable ketone, acetone (propanone). Thus, A is CH3–C(OH)=CH2 and B is CH3–C(=O)–CH3.

Related JEE Main Chemistry questions

• Arrange the following carbanions in decreasing order of basicity: (A) CH3CH2−, (B) CH2=CH−, and (C) HC≡C−.
• In acid-catalyzed hydration of alkenes, all alkenes except ethene generally give rise to which type of alcohol product?
• Which of the following organic compounds has the same hybridization as the carbon atom in its combustion product, CO2?
• What is formed when CH3MgX reacts with CH3C≡CH?
• Which of the following reagent sets can be used to convert propene into 1-propanol?
• When ethyne (H–C≡CH) is treated first with (1) NaNH2 in liquid NH3 and then with (2) CH3CH2Br, product X is formed. If X is again subjected to the same two-step sequence, the product Y obtained is:

⚔️ Practice JEE Main Chemistry free + battle 1v1 →