Question

Compare the relative stability of the following species and indicate their magnetic properties;

O₂,, (superoxide), (peroxide)

Answer 1

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 = N_b and the number of antibonding orbitals = 4 = N_a.

Bond order

= 2

Similarly, the electronic configuration of can be written as:

N_b = 8

N_a = 3

Bond order of

= 2.5

Electronic configuration of ion will be:

N_b = 8

N_a = 5

Bond order of =

= 1.5

Electronic configuration of ion will be:

N_b = 8

N_a = 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 .