18.2.2—Hydrolysis of esters by dil. acid and by dil.
- Syllabus
- 9701–2028–2029
- Objective
- 18.2.2
- Level
- AS
Ester hydrolysis gives different products in acid and alkali
Dilute acid hydrolysis of an ester is reversible and gives a carboxylic acid plus an alcohol. Dilute alkali hydrolysis gives a carboxylate salt plus an alcohol and is effectively driven to completion.
Heat supplies energy and the reagent determines whether the carboxyl group remains protonated. Acidification after alkaline hydrolysis converts the carboxylate into the free acid.
CH₃COOCH₂CH₃ + H₂O ⇌ CH₃COOH + CH₃CH₂OH in acid; with NaOH, products are CH₃COONa + CH₃CH₂OH, followed by acidification if ethanoic acid is required.
Do not write identical products for acid and alkaline hydrolysis, and do not forget reversibility in the acid route.
ConceptA-Level CAIE Chemistry AS