Question

An unknown compound ‘A’ has a molecular formula C4H6. When ‘A’ is treated with excess Br2, a new substance ‘B’ with molecular formula C4H8Br2 is formed. The unknown compound ‘A’ when reacted with ammonical silver nitrate solution forms a white precipitate. The unknown compound ‘A’ could be:

• A. But-1-yne
• B. But-2-yne
• C. But-1-ene
• D. But-2-ene

Hint:

Terminal alkynes react with AgNO3 in ammoniacal solution to form a white precipitate due to silver acetylide formation.

Answer 1

The Correct Option is A

The molecular formula C4H6 indicates an alkyne. A positive reaction with ammonical silver nitrate (precipitate formation) confirms the presence of a terminal alkyne group. Consequently, But-1-yne is the sole terminal alkyne that satisfies these criteria.