Question

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

Answer 1

Molecular orbitals of O₂

1. Electronic configuration of O atom is 1s² 2s² 2p⁴ 

2. Electronic configuration of O, molecule is

σ1s² σ*1s² σ2s² σ*2s² σ2p_x² π2p_y² π2p_z² π*2p_y¹ π*2p_z¹

3. Bond order = \(\frac{N_b-N_a}{2}\) ⁼ \(\frac{10-6}{2}\) = 2

4. Molecule has two unpaired electrons, hence it is paramagnetic.