Question

Give chemical tests to distinguish between the following pairs of compound .
(a) Phenol and benzoic acid
(b) Propanol and propanone
(c) Benzoic acid and ethyl benzoate

Answer 1

(a)

Reagent	Phenol	Benzoic acid
Neutral FeCl3	Dark-green, grey violet complex	No colour change
NaHCO3 (sol.)	No gas evolves	CO2 evolves

(b)

Reagent	Propanol	Propanone
NaOH + I2 heat	No reaction	Yellow ppt of CHI3 forms

(c)

Reagent	Benzoic acid	Ethyl benzoate
NaHCO3 (aq)	CO2 gas evolves (Effervesence of CO2)	No gas evolves