Question

Distinguish between propene and propyne.

Answer 1

Propene and propyne can be distinguished by using ammoniacal silver nitrate test.
Propyne has an acidic hydrogen due to which it readily reacts with ammonical silver nitrate giving white precipitate while propene does not give any precipitate.
Reaction of propyne with ammoniacal silver nitrate is given below:
$C{H}_{3}CH\equiv CH+2\left[Ag\right(N{H}_3{)}_2{]}^{+}O{H}^{-}\to Whiteppt$.