NEET-XI-Chemistry
04: Chemical Bonding and Molecular Structure
- #36Compare the relative stability of the following species and indicate their magnetic properties;
O2,
,
(superoxide), 
(peroxide)
Ans : There are 16 electrons in a molecule of dioxygen, 8 from each oxygen atom. The electronic configuration of oxygen molecule can be written as:
Since the 1s orbital of each oxygen atom is not involved in boding, the number of bonding electrons = 8 = Nb and the number of anti-bonding orbitals = 4 = Na.
Bond order
= 2
Similarly, the electronic configuration of can be written as:
Nb = 8
Na = 3
Bond order of
= 2.5
Electronic configuration of ion will be:
Nb = 8
Na = 5
Bond order of = 
= 1.5
Electronic configuration ofion will be:
Nb = 8
Na = 6
Bond order of= 
= 1
Bond dissociation energy is directly proportional to bond order. Thus, the higher the bond order, the greater will be the stability. On this basis, the order of stability is
.