Bromination of Benzene: Synthesis and Purification of Bromobenze

Only available on StudyMode
  • Download(s) : 269
  • Published : February 6, 2002
Open Document
Text Preview
Organic Chemistry I
LAB EXAM: FINAL
BROMINATION OF BENZENE
SYNTHESIS AND PURIFICATION OF BROMOBENZENE: PROCEDURE

DATA TABLE

ChemicalBoiling point CMelting Point CDensity g/mLSolubility Benzene80.15.50.88Slightly in H2O
Toluene110.6-930.87Slightly in H2O
Bromobenzene155-156-30.81.50Insoluble
Dibromobenzene220.4087.310.96Insoluble

MATERIALS:
Graduated cylinder
Weight scale
Buchner funnel
Filter flask
Rubber stopper
Hot plate
Thermometer
Conical funnel
Various size beakers
Fractionating column (for reflux)
Various sized round bottom flasks
Distillation head
Condenser
Vacuum adapter
Clamps and stands
Test tubes

PROCEDURE:

Pre Lab:

The experiment should be carried out AWAY from the sunlight. Before beginning the experiment, we need to make sure that the benzene used in the experiment is free of toluene and water. To do this, we must put anhydrous calcium chloride into a flask of benzene to "dry" it and remove the toluene. This is then decanted into a vacuum filter, which will leave only pure benzene. Synthesis of Bromobenzene:

Set up a reflux and place in a cold-water bath. In addition to setting up the reflux apparatus, set up an inverted funnel gas trap. This will collect the hydrogen bromide gas in the water and not in our lungs when the reflux takes place. Pour 2.3 mL of benzene in the round bottom flask of the reflux apparatus. After this, pour the iron (III) bromide (FeBr3) into the same round bottom flask. If there is a vigorous initial reaction, wait until this has almost stopped and then heat the water bath to a temperature of 25-30O C to initiate the reflux. Reflux at this temperature for an hour. After an hour has passed, raise the temperature of the water to 65-70O C, and allow refluxing for about 45 minutes. At this point, the color of the liquid should be dark. At this point, the reaction between the benzene and the bromide molecules should be complete. Purification of...
tracking img