Carboxylic acids are more acidic than alcohols because
Correct answer: B. the carboxylate ion formed is stabilised by delocalisation of the negative charge over two oxygen atoms
- A. they contain more hydrogen atoms
- B. the carboxylate ion formed is stabilised by delocalisation of the negative charge over two oxygen atoms
- C. they are liquids at room temperature
- D. their molecules are larger
Explanation
Losing the acidic hydrogen gives an ion whose charge is shared equally between the two oxygens, so the two carbon to oxygen bonds become identical in length and the ion is far more stable than an alkoxide. That stability makes the loss of the proton much more favourable. This is why an acid liberates carbon dioxide from a carbonate while an alcohol does not.
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About Reactivity of Carboxylic Acids
Carboxylic acids show acidic behaviour because their carboxylate ions are resonance-stabilised, and electron-withdrawing groups can change their strength. Reactions include neutralisation, esterification, formation of acid chlorides and amides, reduction, decarboxylation and substitution at the acyl carbon, which differs from the reactions of phenols.
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