Question

Draw the M.O diagram for oxygen molecule calculate its bond order and show that O₂ is paramagnetic.

Answer 1

MO Diagram for O₂ molecule

Electronic configuration of O atom:
1s² 2s² 2p⁴

Electronic configuration of O₂ molecule:
σ_1s², σ_1s^*2, σ_2s², σ_2s^*2, σ_2px², π_2py² π_2pz² π_2py^*1 π_2pz^*1 

Bond order = `("N"_"b" - "N"_"a")/2`

`= (10 - 6)/2`

= 2 

The molecule has two unpaired electrons hence it is paramagnetic.