How is phenol prepared form
(i) chloro benzene , (ii) isopropyl benzene

Explanation

(i) chloro benzene:
When Chlorobenzene is hydrolysed with 6-8% NaOHa 300 bar and 633 K in a closed vessel, sodium phenoxide is formed which on treatment with dilute HCl gives phenol.

(ii) Isopropyl benzene:
A mixture of benzene and propene is heated at 523 K in a closed vessel in presence of `H_(3)PO_(3)` catalyst gives cumene (isopropylbenzene). On, passing air to a mixture of cumene and 5% aqueour sodium carbonate solution, cumene hydro peroxide is formed by oxidation. It is treated with dilute acid to get phenol and acetone. Acetone is also an important by product in this reaction.