Methanoic acid is used in rubber, textile, dyeing, leather, and electroplating industries. Ethanoic acid serves as a solvent and is used in the food industry as vinegar. Hexanedioic acid is crucial in manufacturing nylon-6, 6. Esters of benzoic acid find ...

Aromatic carboxylic acids avoid Friedel-Crafts reactions due to deactivation caused by the carboxyl group. The carboxyl group acts as a deactivating and meta-directing group in electrophilic substitution reactions.

Carboxylic acids with alpha-hydrogens undergo halogenation at the alpha-position using chlorine or bromine in the presence of red phosphorus, a reaction known as Hell-Volhard-Zelinsky reaction.

Sodium borohydride is ineffective in reducing the carboxyl group in carboxylic acids. Diborane is preferred for reduction as it selectively targets the carboxyl group without affecting other functional groups like ester, nitro, or halo groups.

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.

Charge delocalization, illustrated by resonance structures I-V, increases the stability of phenoxide ions. The phenol molecule is less stable due to charge separation in its resonance structures, favoring the ionization of phenol.