Question

Write two reactions to prove the acidic nature of ethyne

Answer 1

Ethyne ( Acetylene) is much less acidic then water or ethanol. So it reacts with very strong bases.

C2H2 reacts with sodium amide in liquid ammonia and form sodium acetylide.
NaNH2 + C2H2 -----→ NaC2H + NH3

C2H2 also reacts with Butylithium to form lithium acetylide.
C2H2 + Bu Li --------→ LiC2H + BuH