Question

Give the molecular orbital energy diagram of N₂ and O₂. Write the bond order of N₂ and O₂.

Answer 1

Molecular orbital energy level diagram (MOED) of 'N₂' :

Electronic configuration of nitrogen (Z = 7) is 1s² 2s² 2p³. Since nitrogen atom has 7 electrons, the molecular orbitals of nitrogen molecule (N₂) has 14 electrons which are distributed as below :

Molecular orbital energy level diagram of N₂ molecule

• Bond order =  (8 2)/2 = 3 (N ≡ N)

• Absence of unpaired electrons showed that N₂ molecule is diamagnetic.

MOED of 'O₂' :

Electronic configuration of Oxygen (Z = 8) is 1s² 2s² 2p⁴ . Since Oxygen atom has 8 electrons, the molecular orbitals of Oxygen molecule (O₂) has 16 electrons, which are distributed as below :

Molecular orbital energy level diagram of O₂

• Bond order = (10 - 6)/2 = 2(O = O)

• Presence of two unpaired 6 electrons (π^* _2p¹y π*_2p¹z,) showed that O₂ molecule is paramagnetic.