C2H2 – ethyne or acetylene
Electronic configuration of C is ground state -1s2 2s2 2P2
Electronic configuration of C excited state – 1s2 2s2 2P3
Valance orbital representation
Sp hybridised, C contains 2 impaired electron and one each in py and pz two sp hybridised C combines with two 1s1 orbitals of H.
Two more hybrid orbitals each carbon overlap with Is atomic orbitals of hydrogen to form sigma bonds. The unhybridised 2pz orbitals of both the carbon atoms now overlap sideways to form carbon-carbon pi-bond.
