Question

What is the reactant P and 'Q' that will react with benzene to give phenol?

Options

• P is Oleum and Q is NH₃

• P is Oleum and Q is HBO₂

• P is Oleum and Q is molten sodium hydroxide followed by H⁺

• P is Oleum and Q is HCl

Answer 1

P is Oleum and Q is molten sodium hydroxide followed by H⁺

Explanation:

Benzenesulphonic acid can be obtained from benzene by reacting it with oleum. Benzenesulphonic acid thus formed is treated with molten sodium hydroxide at high temperature which leads to the formation of sodium phenoxide. Finally, sodium phenoxide on acidification gives phenol.