Some commercially important carboxylic acids are ethanoic acid Phenyl methanoic and benzoic acid. Let us study their industrial preparation :md uses.
1. ETHANOIC ACID (ACETIC ACID)
From ethyl alcohol. In the method. ethyl alcohol is first dehydrogenated with hot reduced copper to acetaldehyde obtained as oxidized with air in the presence of manganous acetate as catalyst to acetic acid
It can also is produced from carboxylation of methanol in the pr6cnce of rhodium catalyst
Acetic add is also obtained in dilute form (called vinegar by the fermentation of ethyl alcohol with bacteria. Acetobacter in the presence of air. This a very old method for obtaining vinegar.
Uses of Ethanoic Acid
1. Solvent for many or11anic chemicals especially in the textile. paint and colour making industry.
2. Starting material for the synthesis of many organic compounds. manufacture of rayon fibre.
3. Preservative, flavoring and tenderizer for foods, pick led foods.
4. Used in cooking (vinegar)
Uses of Phenylmethanoic Acid.
2. Preservative for foods. such as canned fruits and m juices; pharmaceuticals and cosmetics.
3. Treatment of ringworm as an ointment (Whitfield) . In all the above ~ the main work the acid does is to prevent and n:duce growth of microbes or germs
4. Primary standard in titrimetry to Standardize alkalis
Distinction between Alcohols and Carboxylic Acid.
DERIVATIVS OF CARBOXYLIC ACID
Functional derivatives of acids refer to series of closely related organic compounds which can be structurally obtained by the replacement of -OH pan of carboxyl group of the acids by – X, -NH2 -OR’ or -OCOR respectively.