Resonance structure and average bond order SO4 2- CH3COO- HCO3- and NO3-
[attachment id=0 msg=2615]
In sulphate ion there are total six bonds around the sulphur atom with four oxygen atoms in every structure so the average bond order is 6 / 4 that is 1.5
[attachment id=0 msg=2618]
In acetate ion, carbon central atom has three bonds with two oxygen atoms in every resonating structure.
So the average bond order is 300/2 batteries 1.5
[attachment id=0 msg=2619]
[attachment id=0 msg=2620]
In hydrogen carbonate ion carbon is a central atom and it has 4 bonds with three oxygen atoms in every resonating structure so the bond order is 4 /3 = 1.3333
[attachment id=0 msg=2621]
In nitrate ion ,central element is nitrogen and is bonded to three oxygens using four bonds in every resonating structure.
So the bond order is 4 /3=1.3333