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. | |
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© Dr. Ian Hunt, Department of Chemistry |