Sciencemadness Discussion Board

Benzene Bromination

misdemeanor - 29-3-2006 at 11:16

C6 H6+br mol to mol added small amount fe br3 yielded no bromo benzene also c6 h6 + br mol to mol + small amount of fe with appropriate amount of br for in situ fe br3 yielded no bromo benzene. what have i done wrong

chochu3 - 29-3-2006 at 19:24

is your bromine water free. Maybe if your iron does not have enough surface area.

felonious - 30-3-2006 at 09:35

bromine was drawn from sodium bromide and calcium hypochloride. i used 4 ot steel wool , not much and clean. benzene is lab grade. the steel wool is consummed. no bromo benzene. any thoughts to my errors?what do you mean is my bromine water free? 1/4mol to1/4mol bromine to benzene. the bromine was distilled from the sodium bromide calcium hypochlorite hcl mixture.should this reaction be done in toluene?

[Edited on 30-3-2006 by felonious]

chochu3 - 5-4-2006 at 00:17

I meant if they did not form two layers polar/nonpolar from water solvating the bromine. It sounds as if it did react; is it clear and does it have a funny halogen smell? Try freezing it down to zero degrees celsius to see if its just benzene.

misdemeanor - 5-4-2006 at 11:19

MY BROMINE WORKED WELL ON TOLUENE NOT BENZENE THOUGH I USED CATALYST HEAT ETC... BOOK SAYS IT WORKS. SAW A VIDEO THAT WAS VAGUE YET IT WAS CLEAR THE REACTION WORKED. ANY HELP APPRECIATED.

leu - 5-4-2006 at 18:25

Gatterman states this reaction must be agitated, perhaps that's why it didn't work :P Bromine can be purified by dehydration by shaking with an equal amount of concentrated sulfuric acid, then distilled :cool:

[Edited on 6-4-2006 by leu]

[Edited on 6-4-2006 by leu]

chochu3 - 10-4-2006 at 22:04

toluene forms an azetrope with water, so it could be the problem.