To prepare a pure sample of 2,4,6-Tribromophenol through bromination.

 To prepare a pure sample of 2,4,6-Tribromophenol through bromination.

Theory:

 2,4,6-Tribromo phenol can be prepared by the action of bromine on phenol.

C6H5-OH + 3Br2 ⇾ Br3C6H2 -OH (Tribromophenol) +  3HBr

The presence of the hydroxyl group in the benzene ring activates the benzene nucleus for electrophilic substitution. The white ppt. of tribromo phenol is separated by filtration through a Buchner funnel, washed with water, and crystallized from water-alcohol mixture.

Requirements: 

 250 ml round-bottomed flask, air condenser, Buchner funnel, filtration flask, suction pump, 

Chemicals required:

Phenol= 50 g, Bromine=8.0 ml.

Chemical Equations:

Procedure:

1. Dissolve 5.0 g of phenol in water in a round-bottomed flask fitted with an air condenser.

2 Cool the solution in ice-cold water and add 8.0 ml. of bromine to phenol solution dropwise with the help of a separating funnel or burette with continuous stirring.

4. Allow the reaction mixture to stand for half an hour. 

5 Separates the white ppt. formed by filtration through a Buchner funnel using a suction pump and wash with water.

6. Crystallise the products from water-alcohol mixture. 

7. Note the color, weight, and melting point of the product formed.

Result: 

Colour = Colourless needles

Yield =12.0g.

Melting ponit = 93° C