Question 41
HydrocarbonsWhich of the following compounds will give a precipitate with an aqueous ammoniacal solution of copper (I) chloride?
- A.CH3CH = CHCH3
- B.CH3C ≡ CCH3
- C.HC ≡ C–CH2CH3
- D.CH2 = CH–CH = CH2
Show the answer and explanation
Answer: C (HC ≡ C–CH2CH3)
Explanation
Only alkynes with a terminal ≡C–H (an acidic hydrogen) form a red precipitate of copper(I) acetylide. But-1-yne has one; but-2-yne and the alkenes do not.