Terminal alkynes show acidic character due to:
- A. Terminal carbon atoms are sp hybridized
- B. Terminal carbon atoms are sp2 hybridized
- C. Terminal carbon atoms are sp3 hybridized
- D. Terminal carbon atoms show hydrogen bonding
Explanation
An sp hybrid orbital has 50 per cent s character, so it holds the bonding electrons closer to the carbon nucleus and the attached hydrogen is released more easily as a proton. This is why ethyne gives a precipitate with ammoniacal silver nitrate while ethene and ethane do not. Acidity therefore rises with s character in the order sp3 to sp2 to sp.