Question

What is the bond order of carbon monoxide?

Answer 1

Probably 3.

Explanation:

Most Lewis descriptions of carbon monoxide feature a triple bond with formal charge separation of the carbon and oxygen nuclei. There are `6+4=10` valence electrons, and these give a `""^(+):O-=C:^(-)` Lewis structure. Such a representation rationalizes the coordination of carbon (and not oxygen) to a metal centre.

Around oxygen, there are 7 electrons and hence a positive charge; around carbon there are 7 electrons, and hence the formal negative charge. A Lewis structure of `\mathbf( :stackrel(..)"O"=C:` can also be advanced as a representation of electronic structure.