Acidic Nature of Alkynes
The acidic nature of hydrocarbons can be determined with the help of the percentage (%) of s-character of the hydrocarbon. The greater the percentage of s-character of a hydrocarbon, the more will be its acidic nature.
| Hydrocarbon | Hybridization | % s-character |
| Alkanes | sp3 | 25% |
| Alkenes | sp2 | 33.3% |
| Alkynes | sp | 50% |
As alkynes have 50% s-character, they are the most acidic in nature. An sp-hybridized carbon atom is more electronegative than sp2 or sp3 carbon atoms. Due to greater electronegativity of sp hybridized carbon atom in ethyne, hydrogen atom is less tightly held by the carbon and hence, it can be removed as a proton (H+) by a strong base like sodium metal and sodamide.
