Resonance capabilities carboxylic acids

Scheme 2.8 Resonance capabilities of carboxylic acids compared to alcohols.

The ionization of a carboxylic acid gives a carboxylate anion R-COO", and this structure is capable of resonance delocalization of charge. That is, there exists contributing resonance structures for the carboxylate anion the anion is a resonance hybrid of two structures (below), which, being of equal stability, contribute equally. 

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