Chapter 4: Resonance

Ranking Resonance Structures

The following examples have been chosen to help illustrate some common mistakes and how to avoid them.

1.		The mistake is to just look at the location of the +ve charge and the electronegativity of the associated atom (rule 4) and to overlook to octets at C and O (rule 1) and the number of covalent bonds (rule 2) which are more important factors.
2.		The mistake is to focus on the maximised number of covalent bonds (rule 2) and the absence of formal charges (rule 3) but overlook the fact that N can't form 5 bonds since N can not expand its octet and therefore the contributor on the left is not possible.
3.
4.
5.
6.

© Dr. Ian Hunt, Department of Chemistry