Question

How will you distinguish between the following pair of compounds? 

Chlorobenzene and benzyl chloride

How will you distinguish between benzyl chloride and chlorobenzene?

Answer 1

Property	Chlorobenzene	Benzyl chloride
Structure	Chlorine atom attached directly to the benzene ring.	Chlorine atom attached to the benzyl (CH2) group.
Type of compound	Aromatic halide	Benzylic halide
Reactivity	Less reactive towards nucleophilic substitution due to resonance stabilization of the C-Cl bond.	More reactive towards nucleophilic substitution as the C-Cl bond is on a benzylic carbon.
Reaction with NaOH	Does not undergo nucleophilic substitution with aqueous NaOH on heating.	Undergoes nucleophilic substitution with aqueous NaOH on heating to give benzyl alcohol.
Reaction with AgNO3	No precipitate formed with AgNO3 solution.	White precipitate of AgCl formed with AgNO3 solution.
Combustion behavior	Burns with a smoky flame due to aromatic ring.	Burns with a clear flame.
Use in Tests	Differentiated from benzyl chloride by slower or no reaction with AgNO3 and NaOH.	Differentiated by quick reaction with AgNO3 to form AgCl and with NaOH to give benzyl alcohol.