Give the structures of the compounds A and B:

How can you obtain from:
(i) Benzene sulphonic acid.
(ii) Aniline.

Explain why phenol has a much lower pKa value than ethanol.

Arrrange the following groups of compounds in order of decreasing acidity:

(ii)    Phenol, o-chlorophenol, m-chlorophenol, p-chlorophenol.
(iii)   o-cresol, m-cresol, p-cresol, phenol.