Sciencemadness Discussion Board

Bromine

kemikallyimbalanced - 11-6-2007 at 16:41

Is bromine really that hard to work with? Will a ton of fumes come shooting out right after I open the container? Should I put it in the freezer? Any tips on handling bromine properly will be nice. Thanks.

evil_lurker - 11-6-2007 at 19:29

You know what, I have found that bromine is pretty easy to work with.

Long as its at room temp or below, when you go to open the bottle it will hiss a little bit (like an unshook soda) and will fume off just a little bit, and moreso when pouring.

Teflon lined caps are great and will hold your bromine for a long time... freezing isn't necessary but it doesn't hurt either.

Just do not get it on your skin, and have plenty of ventilation when your working with it and you should be OK.

Waffles - 11-6-2007 at 20:38

the main obstacle and difficulty with working with bromine is having a sound method of storage. if you wear gloves, are educated about its reactivity, and work with ventilation, bromine isn't anything to get worked up about.

The_Davster - 11-6-2007 at 21:10

Yup, thats about it, work with it cool, and you should have no issues, especially in small ammounts, with good ventilation.

I keep 5mL or so of it in a glass stoppered flask outside. Enough leaks at -20 to stink up the freezer.

[Edited on 11-6-2007 by The_Davster]

Nerro - 11-6-2007 at 23:44

It doensn't take much Br2 to stink up a freezer though.

The most redeeming feature of Br2 is that it will evaporate quickly and completely when you're working with it. So you won't generally have to worry about little droplets of it staying behind and getting on your skin later. That being said, do worry about getting it on your skin! Few things suck more than a chemical burn caused by exposure to liquid bromine. I've heard the wounds can take weeks or even months to heal...

PainKilla - 12-6-2007 at 08:48

I've had bromine sitting away in a freezer for a 6 months or so, under an equivalent amount of concentrated sulfuric. Works rather well for prolonged storage, and the sulfuric also keeps it dry.

woelen - 12-6-2007 at 10:49

Isn't this very irritating, if you want to take out some of the bromine? You first need to let is warm up, so that it melts, en then taking out the Br2, with H2SO4 sticking to it, isn't that a real pain?

PainKilla - 12-6-2007 at 11:29

Once the bromine melts, there is still no vapor coming out of the container as it's still under the sulfuric, and thus it's quite easy to pipette out... it's high density also ensures you don't add H2SO4 to whatever destination you are adding it to.

Anyway, I'd rather have that small wait than deal with the fumes, which otherwise smell less than appealing.

Edit - From Vogel (3 ed. : 189):

"Bromine. The commercial product may be dried (and partially purified) by shaking with an equal volume of concentrated sulphuric acid, and then separating the acid. Chlorine, if present, may be removed by fractionation in an all-glass apparatus from pure potassium bromide : the b.p. is 59°/760 mm. The analytical reagent grade is satisfactory for most purposes where pure bromine is required."

[Edited on 12-6-2007 by PainKilla]

Jdurg - 12-6-2007 at 17:15

The biggest problem with with bromine is indeed the storage. It WILL eventually find a way to leak out of virtually all containers. I had it in an amber glass bottle with a pure Teflon cap and it still leaked out. I had it in a sealed glass ampoule and although it took about 1 year, it started to leach out of the thin glass and eat away at the glass. Finally, I sealed it in a glass ampoule with some thicker glass, then sealed it in an acrylic cast resin block and it has not leaked out at all.

When you store bromine, it is a good idea to put in an amber glass vial with a teflon lid. Then wrap the outside of the bottle where the lid meets the vial with teflon tape. Take the wrapped vial and put it in a large steel can with vermiculite. Press the top of the lid of the can down tight. The Br2 will still leach out and etch away at the can and stink up the local area, but that's the best way to keep it long term in a way you can still use it.

kemikallyimbalanced - 12-6-2007 at 22:39

Wow, thanks for all the info. I really appreciate that :D I will definitely just order enough for my reaction as storing it around here could cause problems.

woelen - 14-6-2007 at 09:25

You simply can order bromine? As a private person?

Fleaker - 19-6-2007 at 11:59

Or store it with sodium thiosulfate. Whenever bromine arrives, it's usually accompanied with thiosulfate to make it safer to ship.

BTW, Acros has a good deal on bromine, 1L (3.1kg) for ~$88

evil_lurker - 19-6-2007 at 12:07

Quote:
Originally posted by Jdurg
The biggest problem with with bromine is indeed the storage. It WILL eventually find a way to leak out of virtually all containers. I had it in an amber glass bottle with a pure Teflon cap and it still leaked out. I had it in a sealed glass ampoule and although it took about 1 year, it started to leach out of the thin glass and eat away at the glass. Finally, I sealed it in a glass ampoule with some thicker glass, then sealed it in an acrylic cast resin block and it has not leaked out at all.

When you store bromine, it is a good idea to put in an amber glass vial with a teflon lid. Then wrap the outside of the bottle where the lid meets the vial with teflon tape. Take the wrapped vial and put it in a large steel can with vermiculite. Press the top of the lid of the can down tight. The Br2 will still leach out and etch away at the can and stink up the local area, but that's the best way to keep it long term in a way you can still use it.


Bah... thats way overkill.

Get a freaking Qorpak PVC coated amber glass bottle with foam backed PTFE liners and phenolithic caps.

Cynmar sells them... 1L's are around $7 each.

It won't go anywhere, or at least not very much of it at a time (not enough to matter IMO).

YT2095 - 20-6-2007 at 04:43

I keep my long term Br2 in sealed glass ampuoles, and my ready to use in a glass vial with a PTFE cap that came from an IVF clinic, and that`s then sunk in a jar of water in the fridge.

I keep a mixture of KBr and KBrO3 in a jar for a "Just add water" Instant-Bromine generator too, except you add an acid instead of water, it`s a nice way to keep it and lasts forever :)

woelen - 20-6-2007 at 13:29

I don't store bromine (except some in sealed ampoules as collection item). If I want some experiments with bromine, I make some (I now have plenty of KBrO3 and KBr) and pipette it from the liquid and if needed, I dry it with some H2SO4.

Nick F - 10-9-2007 at 10:27

If you're making your own bromine, rather than buying it, then I would suggest that its ease of manufacture makes the problem of storing bromine irrelevant - just make it as needed. That being said, I have stored bromine, and a flask with a ground glass stopper (with a little grease) in the freezer seems in my experience to be fine, certainly up to a few years.

But my main reason for replying to this thread is to ask a question - does anyone have a good source for K/NaBrO3? I've heard that it is possible to buy it cheaply as a flour bleach, or something similar, but I haven't been able to. I got some off ebay, but it would be nice to have a more reliable source, without paying chem supplier prices. Perhaps someone could PM me if they have a cheap source or a large excess that they don't need..?

Phosphor-ing - 10-9-2007 at 11:42

I know you can get KBr/NaBr at pool/spa suppliers. But as for the Bromate I'm not sure.:(

woelen - 10-9-2007 at 13:31

I make my own bromate. That works very well and is in fact much easier than making chlorate, because bromate does not bubble out of solution in an electrolysis cell:

http://woelen.scheikunde.net/science/chem/exps/KBrO3_synth/i...

Try to find a platinum anode for best results. The eBay seller uGems sells platinum wire at good prices (appr. $5 per inch of 0.3 mm wire). With such wire, a decent power supply and a week of patience you can make yourself a lot of potassium bromate. I made a few tens of grams in one evening. It really is easy. Use KBr as your starting chemical. KBr is easy to find and with KBr, the crystals of KBrO3 simply settle at the bottom.

Unfortunately, for home chemists, there is no reliable source of bromates. Sources come and sources go.

One source for NaBrO3 is the following: http://www.crystalgrowing.com/index_d.htm
At the left click on 'chemikalien'. I'm not sure how long this source will last. It is changing frequently and chems come and go all the time. A few months ago thay also had K2Cr2O7 and now that has gone, but in exchange, the NaBrO3 appeared on their site. So grab it while you can ;).

Sauron - 10-9-2007 at 20:15

If you just cool the bottle down in an ice bath prior to opening it, the red vapor over the liquid Br2 will disappear (condense) and you can handle the transfer quite easily. I'd still use a hood, and wear gloves and goggles. A large syringe (I have as 100 ml Hamilton for this purpose) is a very convenient way to transger up to 300 g Br2 at a time.