Carboxylic acids and esters (A-level only) (3.3.9.1) | AQA A-level Chemistry - (7405)

3.3.9.1 Carboxylic acids and esters (A-level only)

Content	Opportunities for skills development
$The structures of: carboxylic acids esters. Carboxylic acids are weak acids but will liberate CO₂ from carbonates. Carboxylic acids and alcohols react, in the presence of an acid catalyst, to give esters. Common uses of esters (eg in solvents, plasticisers, perfumes and food flavourings). Vegetable oils and animal fats are esters of propane-1,2,3-triol (glycerol). Esters can be hydrolysed in acid or alkaline conditions to form alcohols and carboxylic acids or salts of carboxylic acids. Vegetable oils and animal fats can be hydrolysed in alkaline conditions to give soap (salts of long-chain carboxylic acids) and glycerol. Biodiesel is a mixture of methyl esters of long-chain carboxylic acids. Biodiesel is produced by reacting vegetable oils with methanol in the presence of a catalyst.$	$AT b, d, g and k PS 4.1 Students could make esters by reacting alcohols with carboxylic acids, purifying the product using a separating funnel and by distillation. AT b, d, g, h and k Students could identify an ester by measuring its boiling point, followed by hydrolysis to form the carboxylic acid, which is purified by recrystallisation, and determine its melting point.$

Content

Opportunities for skills development

The structures of: carboxylic acids esters. Carboxylic acids are weak acids but will liberate CO₂ from carbonates. Carboxylic acids and alcohols react, in the presence of an acid catalyst, to give esters. Common uses of esters (eg in solvents, plasticisers, perfumes and food flavourings). Vegetable oils and animal fats are esters of propane-1,2,3-triol (glycerol). Esters can be hydrolysed in acid or alkaline conditions to form alcohols and carboxylic acids or salts of carboxylic acids. Vegetable oils and animal fats can be hydrolysed in alkaline conditions to give soap (salts of long-chain carboxylic acids) and glycerol. Biodiesel is a mixture of methyl esters of long-chain carboxylic acids. Biodiesel is produced by reacting vegetable oils with methanol in the presence of a catalyst.

AT b, d, g and k PS 4.1 Students could make esters by reacting alcohols with carboxylic acids, purifying the product using a separating funnel and by distillation. AT b, d, g, h and k Students could identify an ester by measuring its boiling point, followed by hydrolysis to form the carboxylic acid, which is purified by recrystallisation, and determine its melting point.

Carboxylic acids and esters (A-level only)