How many resonance structures are required in the electron-dot structure of #CO_3^(2-)#?

1 Answer
Jun 26, 2017

Well, we would usually draw THREE resonance isomers......

Explanation:

And the Lewis structure is #(O=)C(-O^(-))_2#.

Of course, in the actual molecule/ion, ALL of the #C-O# bonds are equivalent. You should look up the #C-O# bond lengths in #CO_2#, #CO_3^(2-)#, #""^(-):C-=O^(+)#, and #R_3C-OH# for reference.