What test/s could be used to differentiate carboxylic acid from phenol?

Question

explain how the test/s could differentiate them.

Answer 1

a) add sodium carbonate solution. Phenol dissolves without fizzing, but the acid fizzes.

b) add bromine water. Phenol will give a white precipitate, the acid won't.

c) add neutral FeCl3. Phenol gives a purple colour. The acid may or may not react, but it won't be purple.

Answer 2

nitration;

reagent: use nitric acid

phenol reacts with nitric acid to form a yellow solid of 2,4-dinitrophenol.

carboxylic acid does not undergo this reaction.

Yellow crystalline solid formed indicates presence of phenol...