Question

Distinguish between chlorocyclohexane and chlorobenzene using lucas test

Answer 1

Chloro Cyclohexane and chlorobenzene gives different products with silver nitrate(AgNO3 )  as;

Chlorobenzene do not reacts with 2%Ethanolic silver nitrate solution but chloro cyclohexane reacts with 2%  Ethanolic silver nitrate solution to give a white precipitate.

It is because in chlorocyclohexane , the C-Cl bond is of sp3 hybridization, which follows nucleophilic reaction, but in chlorobenzene , the C-Cl bond is related with an sp2hybridized carbon atom and the C-Cl bond has a partial double bond character due to resonance, so it does not undergo nucleophilic reaction.

Answer 2

Hey dear,

● Chlorocyclohexane vs Chlorobenzene -
When chlorocyclohexane is treated with aq. KOH, cyclohexanol & KCl is formed. This KCl on further treatment with acidified AgNO3 gives white ppt of AgCl.
C6H11-Cl + KOH ---> C6H11-OH + KCl
KCl + AgNO3 ---> AgCl + KNO3

Chlorobenzene does not gives this test.
C6H5-Cl + KOH + AgNO3 ---> NO REACTION

Hope this helps you...