What are the experiments we can do for testing Carboxylic Acids ?

A carboxylic acid can be identified by the following tests:

1. Litmus Test:

Carboxylic acids turn blue litmus red.

2. Sodium Bicarbonate Test:

To a small portion of the organic compound taken in a test tube, a pinch of solid sodium bicarbonate is added. Evolution of carbon dioxide with brisk effervescence shows the presence of carboxylic acid. Alcohols do not give this test.

3. Ester Test:

In this test, the compound to be tested is warmed with small quantity of ethyl alcohol and 2-3 drops of concentrated sulphuric acid. The formation of sweet smelling vapours indicates the presences of some carboxylic acid. The sweet smelling vapours are due to the formation of some ester by reaction between the acid and ethyl alcohol.