Question

How to calculate bond order of superoxide?

Answer 1

Bond order = (no. of bonding electrons - no. of antibonding electrons)/2

Oxygen molecule O2
Molecular electronic configuration: (σ1s)2(σ1s*)2(σ2s)2(σ2s*)2(σ2p)2(π2p)4(π2p*)2
Bond Order = ½ (10 – 6) = 2

Superoxide ion O2-
Molecular electronic configuration:
​ (σ1s)2(σ1s*)2(σ2s)2(σ2s*)2(σ2p)2(π2p)4(π2p*)3
Bond Order = ½ (10 – 7) =​ 1.5

The bond order decreases from 2 (O2) to 1.5 in superoxide ion.