Question
Identify the reagent from the following list which can easily distinguish between 1-butyne and 2-butyne
A.
bromine, $$CC{l_4}$$
B.
$${H_2},$$ Lindlar catalyst
C.
dilute $${H_2}S{O_4},HgS{O_4}$$
D.
ammonical $$C{u_2}C{l_2}$$ solution
Answer :
ammonical $$C{u_2}C{l_2}$$ solution
Solution :
Ammonical cuprous chloride gives precipitate (red) only with terminal alkynes, i.e. alkynes having acidic hydrogen atom, such as butyne-1 $$\left( {CH \equiv CC{H_2}C{H_3}} \right)$$