Question

Convert the following:

Phenol into o-phenol sulfonic acid.

Answer 1

Phenol, on treatment with cold concentrated sulphuric acid (H₂SO₄) at 20-25°C, undergoes sulphonation to give o-phenol sulphonic acid as the major product.

\[\ce{Phenol ->[conc. H2SO4][20-25^\circ C] o-phenol sulphonic acid}\]