Question

What is a discriminating test for the presence of a carboxylic acid?

Answer 1

The classic test is the evolution of gas from when sodium bicarbonate is added.

Explanation:

Take an aqueous solution of the acid, treat this `NaHCO_3`, and the solution will effervesce.

`HCO_3^(-) + HO(O=)CR rarr CO_2(g)uarr + H_2O + ""^(-)O(O=)CR`

As with all chemical tests, you should do it first on an authentic carboxylic acid so that you know what constitutes a positive.