Which of the following statements is correct?

Options

A. Sulphonation of phenol at low temperature is rate-controlled to give o-`HOC_(6)H_(4)SO_(3)H`
B. Sulphonation of phenol at higher temperatures is thermodynamically'controlled to give o-`HOC_(6)H_(4)SO_(3)H`
C. The-OH group is more activating than phenoxide ion towards aromatic electrophilic substitution reactions
D. Brominatiori of phenol in aqueous mediumgives monobrominated phenol while in non aqueous medium, tribrorninated phenol is formed.

Answer

A

Explanation

The reaction is reversible and thus at higher temperatures, mennodynamic.ally controlledpara isomer is formed `PhO^(-)` reacts faster than PhOH with an electrophile because the intermediate formed with `PhO^(-)` is a fairly stable uncharged species while in PhOH, a less stable positively - charged intermediate is formed.

In aqueous solution, some phenol is ionised to give more reactive `PhO^(-)` species, which, in turn, forms a tribrominated phenol. Innon aqeuous medium, the ionisation is not possible and memonobromination of lessreactive.PhOH occurs.