Question

Out of peroxide ion and superoxide ion which has larger bond length and why?

Answer 1

The peroxide ion is O2(2-)(two oxygen atoms with -2 charge).
Bond order of peroxide ion is (Nb-Na)/2=6-4/2=1.[Here Nb and Na denotes no.of e in bonding and antibonding molecular orbitals]
But a superoxide ion is O2(-1).
Again the bond order of this is given by=6-3/2=1.5.
Since bond order varies inversely with bond length,we conclude peroxide ion has larger bond length.