(A Level) Carboxylic acids and acyl chlorides

Learning objectives

Describe the preparation of benzoic acid by oxidising an alkylbenzene with hot alkaline KMnO₄ followed by acid, and the conversion of carboxylic acids into acyl chlorides with PCl₃ and heat, PCl₅ or SOCl₂

Describe the oxidation of methanoic acid (by Tollens', Fehling's, acidified KMnO₄ or K₂Cr₂O₇) and of ethanedioic acid (by warm acidified KMnO₄) to carbon dioxide

Explain the relative acidities of carboxylic acids, phenols and alcohols, and of chlorine-substituted ethanoic acids, from anion stability and the inductive effect

Describe the reactions of acyl chlorides with water, alcohols, phenols, ammonia and amines at room temperature, including the preparation of ethyl ethanoate and phenyl benzoate, and draw the addition–elimination mechanism

Explain why acyl chlorides hydrolyse far more readily than alkyl chlorides, and alkyl chlorides more readily than aryl chlorides