Question

Why are alkynes called unsaturated hydrocarbons?

Answer 1

1. The name alkyne contains the suffix “-yne” indicating the presence of a triple bond between carbon atoms in the molecular structure.
2. Alkynes can readily add four Hydrogen atoms ($\mathrm{H}$) per molecule to become corresponding alkanes(saturated hydrocarbons).
3. Alkynes are called unsaturated hydrocarbons due to the presence of triple bond, making them readily undergo characteristic addition reactions, getting converted into alkanes.
4. Hence alkynes are more reactive than alkanes.
5. Some examples of Alkynes are Ethyne ($\mathrm{HC}\equiv \mathrm{CH}$), Propyne (${\mathrm{CH}}_3-\mathrm{C}\equiv \mathrm{CH}$), etc.