Bromine water

[Lis]

I have been asked in the past to make Bromine water by distilling potassium bromide, manganese dioxide and conc sulphuric acid into a drescher flask with distilled water, I was wondering if anyone makes it this way anymore, as it is quite dangerous.

[Mother]

Hi Lis
Yes, you are correct.To make Bromine Water is dangerous.I buy mine already made from one of the chemical catalogue books I have.500mls.will last a long time as not much is needed for a prac.Costs about $21.00
Hope this helps you
Mother

[juliem]

Hi Lis
I do the same as Mother - can purchase from QStores or Serrata, then it keeps well stored in the fridge
Julie

[Lis]

Thanks Mother and Julie, I will do that next time, Lisa

[Sheryl]

There is an easier way to make Bromine Water:

In a beaker, in the fume cupboard, mix the following ingredients:
4.4g NaBr
21 ml 2 M HCl
30ml 4% Sodium Hypochlorite
28 ml distilled water

Keep is tightly closed bottle & store in the fridge. This is safer than transporting it ready made.

[Robb]

The above methods are great. When it comes to making up Br Water I usually use the small Br Ampoules. This contains a small volume of Elemental Br and allows to make enough solution for use without waste.

This way I seem to make it on a use as needed basis, without the need to worry about the solution going "Stale".

I have Risk Assessments in place for the use of Br Ampoules which greatly reduces uncertainty of handling, storage and use if other people make the solution up.

[Wombat]

Another method for Br water - 0.1M Bromine solution may be made as follows: Weigh 1.67g of potassium bromate and 6.19g potassium bromide. Add 10ml water followed by 15ml 2M H2SO4. Stir. Make up to 100ml with H2O, warm to 60degrees for a few mins in a fumehood. Seal in glass bottle. Store in refrigerator.
Wombat

[Robb]

The only problem with this method though is that the solution is acidic. When used in the Addition reactions of Alkenes the solution may starve the alkene of braches as protons are donated to the double bond therefore re-hydrogenating the process.

The process still works but not as efficient as one would predict.

[Rita]

Hi All
I need Bromine Water for period 2 today. I have 1ml ampoules but don't know what volume they make up to.
Appreciate any help.
Thanks in advance
Rita

[Labbie]

You should not be using the ampoules any more, they were banned years ago.

[Jody1]

I've discovered we have Bromine water already made up in the Chemstore in bottles that look older than I do. One of the chemistry teachers kindly showed me where to find it and also told me that if anyone asks for it to be made up, it should only be done by a Chemistry teacher or qualified chemist.

[AnnNos]

I still use the ampoules. There were 6 here when I started here and I'm using them until they're gone. CSIS has the pure bromine as teacher use only.
I prepare the bromine by using the instructions in CSIS volume 2 appendix B by opening the bromine ampoule (1 ml) under water (200 ml) in a fume cupboard. I used double gloves and break the ampoule with strong scissors or crucible tongs. Store in dark glass bottle away from light.

[rae]

1ml to 200ml water. Make sure you do it in a fume cupboard and wear all your ppe.

[Lyn]

I still have a number of 1ml ampoules in storage but will not make up the solution myself. If a chemistry teacher wishes to make up their own solution then that is fine by me. I have watched an experienced chemistry teacher have a mishap while making up a solution from an ampoule and he received burns on his hand and arm. Information from the scienceassist chemical list says Bromine is fatal if inhaled and causes severe skin burns and eye damage. I would be interested to know if Rita went ahead and made up the solution or passed it onto the chemistry teacher.

[rae]

I have Bromine in a bottle not ampoules. I think it is easier to manage. Never liked ampoules.

[AnnNos]

I thought we used ampoules because we can't keep any more than 10 ml of Bromine on site?

[Labbie]

Then why do they sell in 1L bottles or 500ml bottles?

[rae]

I think I bought 100ml a couple of years ago.

[AnnNos]

Is it bromine or bromine water? Pure bromine is restricted to 10 ml.

[Labbie]

Sorry my mistakeI meant Bromine water.