Question

Sulfonation of benzene with excess sulfuric acid provides

• A. benzenesulfonic acid
• B. p-benezenedisulfonic acid
• C. o-benzenedisulfonic acid
• D. m-benzenedisulfonic acid

Answer 1

Answer: (D)

m-benzenedisulfonic acid

Answer 2

Sulfonation of benzene with excess sulfuric acid provides $m$ -benzenedisulfonic acid. Initially, the replacement of a hydrogen atom from benzene ring by a sulphonic acid group occur, that results in the formation of benzenesulphonic acid. As excess of sulphonic acid is present in mixture, the reaction continues and form $m$ -benzene disulfonic acid.