Question

Which among the following is not the method of preparation of phenol?

Options

• \[\ce{Benzene + conc. H2SO4 ->[\Delta] Phenol}\]

• \[\ce{Cumene ->[(i) O2/CO-naphthenate][(ii) dil HCl, \Delta \text{423 K}] Phenol}\]

• \[\ce{Chlorobenzene ->[(i) NaOH, 623 K 150 atm][(ii) H3O+] Phenol}\]

• \[\ce{Aniline ->[(i) NaNO2 + HCl 273 K][(ii) H2O, \Delta] Phenol}\]

Answer 1

\[\ce{Benzene + conc. H2SO4 ->[\Delta] Phenol}\]

Explanation:

Reaction of benzene with conc. H₂SO₄ will not give phenol. Instead it undergoes·sulphonation to give benzene sulphonic acid.