Question

Give simple chemical tests to distinguish between the following pairs of compounds:  Benzoic acid and Phenol

Answer 1

(ii) Distinguish test between Benzoic acid and Phenol:

NaHCO₃ Test: When Benzoic acid reacts with NaHCO₃, brisk effervescence of CO₂ gas evolved.

Phenol does not give this test.

C₆H₅OH + NaHCO₃ → No Reaction.

Answer 2

Benzoic acid and Phenol : Benzoic acid and phenol can be distinguish by FeCl₃ tests. Both reacts with FeCl₃ to give different colours. Phenol reacts with FeCl₃ to give violet coloured precipitate while benzoic acid give buff coloured precipitate.

Answer 3

When treated with sodium bicarbonate, benzoic acid gives brisk effervescence due to evolution of carbon dioxide gas. No reaction takes place when phenol is treated with NaHCO₃.

C₆H₅COOH + NaHCO₃ → C₆H₅COONa + H₂O + CO₂