Answer: a) Ethyne
It appears that acidic hydrogen is released as the H+ ion. As a result, any H-atom bonded to another atom or group of atoms with a greater electronegativity than that H-atom might be an acidic H–atom. Ethyne has the highest percentage of s-character, as well as the most acidic hydrogen atoms. Ethyne is an alkyne with the chemical formula C2H2 that contains sp hybridised carbon, Ethene is an alkene with the molecular formula C2H4 that contains sp2 hybridised carbon, and Benzene is a cyclic alkene with the molecular formula C6H6 that contains sp2 hybridised carbon. Ethane is an alkane with the molecular formula C2H6 that contains sp2 hybridised carbon. It is made up of sp3 hybridised carbon
- Carbon’s electronegativity is highest in sp hybridised carbon because it lies close to the nucleus and removes electrons from hydrogen, releases ions easily, and acts as an acid.
As a result, ethyne contains acidic hydrogen.