Q. Ammoniacal cuprous chloride will give red precipitate with which one of the following?
A) $CH_{3} - C \equiv C - CH_{3}$
B) $CH_{3} - CH = CH_{2}$
C) ${CH}_{3} - C \equiv CH$
D) ${CH}_{3} - CH = CH - {CH}_{3}$
Explanation
(c)
Ammoniacal cuprous chloride will give red precipitate with 1-alkynes (terminal alkynes).
$CH_{3} - C \equiv CH + 2\left\lbrack Cu\left( NH_{3} \right)_{2} \right\rbrack Cl \rightarrow$
$CH_{3} - C \equiv C - Cu + 2NH_{4}Cl + 2NH_{3}$
(red ppt.)
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.