Distinguish chemically between a) phenol and ethanol b) methanal and ethanal. 2

a) Phenol is an unsaturated aromatic alcohol, while ethanol is saturated aliphatic alcohol.

Ethanol reacts with triiodomethane (iodoform test) and forms yellow precipitate, while phenol does not give this test.

Phenol has benzene ring it under goes diazo coupling reaction, while ethanol doest give this test.

Phenol decolourises bromine solution shows it as unsaturated compound while ethanol does not decolorise bromine solution shows it as saturated compound.

With neutral FeCl3 phenol forms violet complex while ethanol does not.

b) Methanal is nothing but formaldehyde, and ethanal is acetaldehyde.

Methanal on oxidation CO2 gas evolution occurs which gives white ppt in lime water, while ethanal on oxidation does not give CO2 but gives acetic acid.