Question

acetylene shows acidic properties.give two reactions to justify this statement

Answer 1

Acetylene is a terminal alkyne and carbon in acetylene (or in general in a alkyne) is sp hybridised.
The two reactions are :-

1.  HC ≡ CH + Na → HC ≡ CNa = 1/2 H₂.

2.  HC ≡ CH + RM  → RH + HC ≡ CM.

Answer 2

Explanation:

Acetylene shows acidic character because carbon is sp hybridized containing 50% s-character which makes -C-H bond highly acidic in nature. The acidic character of -C-H can be easily justified when heated with sodium metal which displaces hydrogen from acetylene forming sodium acetylide.