Ethyne is acidic in nature in comparison to ethene and ethane. Why is it so?
In ethyne, hydrogen atoms are connected to sp hybridized carbon atoms, but in ethene, they are attached to sp2sp2 hybridized carbon atoms and in ethane, they are attached to sp3sp3 hybridized carbons. The sp hybridized orbitals of carbon atoms in ethyne molecules have the highest electronegativity (50%) due to the highest percentage of s – character (50%): This attracts the shared pair of the C-H bond of ethyne to a greater extent than the sp2sp2 hybridized orbitals of carbon in ethene and the sp3sp3 hybridized orbital of carbon in ethane. In comparison to ethene and ethane, hydrogen atoms may be released as protons more easily in the ethyne molecule.
