C2H2 Hybridization

C₂H₂ Hybridization

In the formation of ethyne molecule, both the carbon atoms undergo sp-hybridization having two unhybridized orbital i.e., 2p_y and 2p_x.

 One sp hybrid orbital of one carbon atom overlaps axially with sp hybrid orbital of the other carbon atoms to form C-C sigma bonds. While the other hybridized orbital of each carbon atom overlaps axially with the half filled s orbital of hydrogen atoms forming  bonds. Each of the two unhybridised p orbitals of both the carbon atoms overlaps sidewise to form two 𝜋 bonds between the carbon atoms. so the triple bonds between the two carbon atoms is made up of one sigma and two pi bonds as shown in the below figure.