Carboxylic acids undergo decarboxylation, losing carbon dioxide, when heated with sodalime (NaOH and CaO). Kolbe electrolysis involves the decarboxylation of alkali metal salts of carboxylic acids during electrolysis, resulting in hydrocarbons with twice the carbon atoms in the alkyl group.

Carboxylic acids can be reduced to primary alcohols using lithium aluminium hydride or diborane. Diborane is preferable as it avoids reduction of other functional groups.

Direct attachment of groups like phenyl or vinyl increases the acidity of carboxylic acids, contrary to the expected decrease due to resonance effects. This is attributed to the greater electronegativity of the sp² hybridized carbon to which the carboxyl carbon ...

Reactions with carboxylic acids and acid anhydrides require concentrated sulfuric acid, while reactions with acid chlorides use a base like pyridine. Acetylation, as seen in the production of aspirin from salicylic acid, involves introducing an acetyl group (CH₃CO) into alcohols ...

Electron-withdrawing groups enhance the acidic strength of phenol, with a more pronounced effect at ortho and para positions. Effective delocalization of negative charge in the phenoxide ion occurs when the substituent is at these positions.