Notes On Carboxylic Acids: Properties - II - CBSE Class 12 Chemistry

The reaction of Carboxylic acids with weak bases (Sodium carbonate & Sodium bicarbonate) is used to detect the presence of the carboxyl group in an organic compound.

Reaction with alcohols:

Carboxylic acids react with alcohols in the presence of a mineral acid catalyst to form esters. The reaction is reversible and is known as esterification.

The esterification of carboxylic acids with alcohols is a nucleophilic acyl substitution reaction.

Reaction with Phosphorous halides:

When carboxylic acids are treated with phosphorous halides (or) thionyl chloride, the -OH group is replaced by a chlorine atom to form acid chlorides.

Carboxylic acids on reduction with lithium aluminium hydride (or) diborane give primary alcohols.

Reaction with Sodalime:

When soda lime heated with sodium salts of carboxylic acids loses Carbon dioxide to form hydrocarbons.This reaction is known as decarboxylation.

α-halo carboxylic acids formation:

Carboxylic acids with α-hydrogen react with Chlorine (or) Bromine in the presence of a small amount of red phosphorous to give α-halo carboxylic acids. This reaction is known as the Hell-Volhard-Zelinsky reaction.

Carboxylic acids do not undergo the Friedel Crafts reaction because the carboxyl group is deactivating and the catalyst Aluminium chloride which is a Lewis acid will reacts with Carboxyl group.

Uses of Carboxylic acids:

Methanoic acid is used as a coagulating agent for latex in the rubber industry.

It is used for the dehydration of hides in the leather industry.

Ethanoic acid is used as solvent and as vinegar in the food industry.

It is also used in the manufacture of plastics and rayon.

Hexane 1, 6 dioic acid (or) adipic acid is used in the manufacture of nylon-66.

Sodium benzoate is used as a food preservative for fruit jams and juices in the food industry.

Higher fatty acids are used for the manufacture of soaps and detergents.

Summary

The reaction of Carboxylic acids with weak bases (Sodium carbonate & Sodium bicarbonate) is used to detect the presence of the carboxyl group in an organic compound.

Reaction with alcohols:

Carboxylic acids react with alcohols in the presence of a mineral acid catalyst to form esters. The reaction is reversible and is known as esterification.

The esterification of carboxylic acids with alcohols is a nucleophilic acyl substitution reaction.

Reaction with Phosphorous halides:

When carboxylic acids are treated with phosphorous halides (or) thionyl chloride, the -OH group is replaced by a chlorine atom to form acid chlorides.

Carboxylic acids on reduction with lithium aluminium hydride (or) diborane give primary alcohols.

Reaction with Sodalime:

When soda lime heated with sodium salts of carboxylic acids loses Carbon dioxide to form hydrocarbons.This reaction is known as decarboxylation.

α-halo carboxylic acids formation:

Carboxylic acids with α-hydrogen react with Chlorine (or) Bromine in the presence of a small amount of red phosphorous to give α-halo carboxylic acids. This reaction is known as the Hell-Volhard-Zelinsky reaction.

Carboxylic acids do not undergo the Friedel Crafts reaction because the carboxyl group is deactivating and the catalyst Aluminium chloride which is a Lewis acid will reacts with Carboxyl group.

Uses of Carboxylic acids:

Methanoic acid is used as a coagulating agent for latex in the rubber industry.

It is used for the dehydration of hides in the leather industry.

Ethanoic acid is used as solvent and as vinegar in the food industry.

It is also used in the manufacture of plastics and rayon.

Hexane 1, 6 dioic acid (or) adipic acid is used in the manufacture of nylon-66.

Sodium benzoate is used as a food preservative for fruit jams and juices in the food industry.

Higher fatty acids are used for the manufacture of soaps and detergents.

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