Bromination of Phenol

The product of the reaction of phenol with bromine water is :

The product of the reaction of phenol with bromine water is :

The product of the reaction of phenol with bromine water is :

The reaction of phenol with excess of bromine water gives

With bromine water phenol gives

Assertion : In bromine/water, phenol gives 2, 4, 6-tribromophenol while in bromine //CS_(2) , a mixture of 2 and 4 bromophenol is formed. Reason : In aqueous medium, ionisation of phenol is more than in CS_(2) solvent.

How much bromine is needed to produce tribromophenol from one mole of phenol?