The total number of electrons in CO is 14. Molecular orbital electronic configuration of CO molecule =σ1s2σ*1s2,σ2s2,σ*2s2,π2px2=π2py2,σ2pz2 Bond order (BO)=
1
2
[ Number of electrons in bonding molecular orbital - Number of electrons in anti-bonding molecular orbital] Bond order of CO=
1
2
[10−4]=
6
2
=3 Thus,x=3 ........(i) Similarly, for O22− ion the total number of electrons is 18 . Molecular orbital electronic configuration of O22− ion =σ1s2,σ*1s2,σ2s2,σ*2s2,σ2pz2,π2px2≃π2py2,π*2px2≃πy* Bond order of O22−=
1
2
[
10−8
2
]=1.0 ....(ii) Thus, from (i) and (ii), we can conclude that the bond order of O22− in term of x is