Other alkynes also have two π-bonds similar to acetylene. Due to the presence of π-bonds, these compounds are highly functional and exhibit additive reactions. This is why alkynes, like alkenes, also fall into the category of unsaturated compounds.
The bond angle in sp hybrids is 180°. Therefore, the value of each H–C–C angle in an acetylene molecule is 180°. And the acetylene molecule is linear. The alkynes have a C≡C bond length of 1.20 A° and C – H bonding length of 1.09 A°. The C≡C bond energy is 192 Kcal per mole.