Aldehydes, Ketones and Carboxylic Acids

Aldehydes (R-CHO), ketones (R-CO-R') and carboxylic acids (R-COOH) are the carbonyl compounds at the heart of organic chemistry - from formaldehyde and acetone in industry to acetic acid in vinegar and the fatty acids in our food. This chapter, worth a reliable 8-12 Board marks and 4-6 JEE/NEET questions a year, builds the chemistry of the carbon-oxygen double bond. We study the structure of the carbonyl group and the nomenclature of aldehydes, ketones and acids; how aldehydes and ketones are prepared (from alcohols, alkenes, alkynes, acyl chlorides by Rosenmund reduction, nitriles by Stephen reaction, and arenes by Etard and Gattermann-Koch reactions); their physical properties; and their reactions - nucleophilic addition (with HCN, NaHSO3, alcohols, ammonia derivatives), the reactions of the alpha-hydrogen (aldol and cross-aldol condensation), the Cannizzaro reaction, oxidation and reduction (Clemmensen and Wolff-Kishner), and the tests that distinguish them (Tollens, Fehling, iodoform, 2,4-DNP). We then cover carboxylic acids - their preparation, the hydrogen-bonded dimer and high boiling points, their acidity and the effect of substituents, and their reactions (salt formation, esterification, anhydride and acid-chloride and amide formation, reduction, decarboxylation, the Hell-Volhard-Zelinsky reaction and ring substitution). Every named reaction, mechanism and exam-favourite distinction is covered.