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Resonance

Quick Reference
Also Known AsResonance hybrid, mesomerism, delocalisation, resonance structures

What is Resonance?

The description of a molecule by two or more Lewis structures (resonance structures) where electrons are delocalized over the molecule. The actual structure is a hybrid (average) of all resonance structures. Examples include benzene, carbonate ion, and ozone. Resonance stabilizes molecules.

Properties & Characteristics

Resonance is the representation of a molecule's actual electronic structure as a hybrid of two or more Lewis structures (resonance structures) that differ only in the distribution of electrons. The actual molecule is a resonance hybrid with a structure intermediate between the contributing forms. Resonance structures lower the overall energy (resonance stabilisation) through delocalisation of electrons. Benzene is the classic example with delocalised π electrons.

Uses & Applications

Understanding resonance explains the stability of aromatic compounds, carboxylate ions, and conjugated systems. It is essential for predicting reaction sites in organic chemistry. Resonance stabilisation is exploited in the design of stable dyes and pharmaceuticals.

Safety Information

Resonance-stabilised compounds like benzene are less reactive than expected but some are carcinogenic. Awareness of resonance helps predict the reactivity and toxicity of aromatic compounds.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Resonance
Synonyms Resonance hybrid, mesomerism, delocalisation, resonance structures

Frequently Asked Questions

The description of a molecule by two or more Lewis structures (resonance structures) where electrons are delocalized over the molecule. The actual structure is a hybrid (average) of all resonance structures. Examples include benzene, carbonate ion, and ozone. Resonance stabilizes molecules.

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