Question

But-1-yne on reaction with dil. \(H_2SO_4\) in presence of \(Hg^{2+}\) ions at 333 K gives :

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is A

• The reaction shown is the hydration of but-1-yne (a terminal alkyne) in the presence of dilute sulfuric acid (H₂SO₄) and Hg²⁺ ions (mercuric ions).
• In this reaction, but-1-yne undergoes Markovnikov's addition where the double bond of the alkyne reacts with water to form an aldehyde as the major product.
• But-1-yne reacts with dilute H₂SO₄ and Hg²⁺ ions at 333 K to form butanal (CH₃CH₂CH₂CHO), which corresponds to option (A).

Thus, the product is butanal (CH₃CH₂CH₂CHO), making (A) the correct answer.

Answer 2

But-1-yne reacts with dilute H₂SO₄ in the presence of Hg²⁺ ions (mercuric sulfate) at 333 K to form acetaldehyde (CH₃CHO) via an electrophilic addition reaction. This is a typical reaction known as the "hydration of alkynes" where the triple bond is converted into a carbonyl group.