The bond order of CO molecule on the basis of molecular orbital theory is: (1) Zero (2) 2 (3) 3 (4) 1

The bond order shows the number of chemical bonds present between a pair of atoms. The Bond Order Formula can be defined as half of the difference between the number of electrons in bonding orbitals and antibonding orbitals.

Bond order formula is given as below

$$\begin{array}{l}Bond order = \frac{1}{2}\left [ a – b \right ]\end{array}$$

where

a = Number of electrons in bonding molecular orbitals.

b = Number of electrons in antibonding molecular orbitals.

(i) CO molecule

Electronic configuration of CO (14 electrons) = (σ1s)2(σ*1s)2(σ2s)2(σ*2s)2(π)4(2pz)2

a = 10

b = 4

Bond order = 1/2 (10 – 4)

Bond order = 3