Question

why C2 molecule has only pi bonds acc. to MOT​

Answer 1

Because C2 molecules ar different to MOT

hope you understand

Answer 2

Explanation:

C2 molecules have been found in vapour state. Their double bonds are made of two pi bonds because four electrons need to be accomodated in each bond. So this is against the rule that there must be a sigma bond before a pi bond is formed in the double bond. Why the anomoly?