Smoke which can be poured

[woelen]

This is a cool experiment I did with ammonia and bromine vapor. The reagents for this experiment are very easy to obtain or to make:

 

http://woelen.scheikunde.net/science/chem/exps/NH3+Br2/index.html

 

Bromine vapor can easily be made if you have a bromide (which can be purchased without problem). If you repeat this experiment, be careful with the bromine vapor, that vapor is very toxic. Follow the safety warnings on the webpage.

[jdurg]

Hey Woelen. I think that in this reaction you may also wind up with some NBr3 if your reaction conditions are just right. I'm pretty sure that you wind up with a mixed reaction of NH3 + 3Br2 => NBr3 + 3HBr. The HBr is then immediately neutralized by the NH3 to give you your NH4Br white smoke. Nitrogen tribromide is so unbelievable unstable that the low amounts you are using are probably resulting in it decomposing immediately without any ill effects. Still, I'd be very careful when doing this experiment.

[Gilded]

I wonder if it's safe to taste ammonium bromide? It seems to be listed as more dangerous than ammonium chloride. Not that its taste probably differs much from NH4Cl.

[alan2here]

Not something I often think when seeing a new chamical

"I wonder how that tastes"

 

How liquidy can you get it while it is still smoke like?

Sorry for the lack of proper scientic words in that last sentance.

[Gilded]

Just that ammonium chloride is widely used in confectionery in Finland and Scandinavia in general... I don't usually go around tasting possibly harmful chemicals though.

[woelen]

No NBr3 is formed in this experiment. NBr3 is not known at room temperature. I have read that it only can exist at ultralow temperatures and even then it only has fleeting existence. This experiment is perfectly safe to perform (as far as explosion risk is concerned), the main risk is the bromine vapor, but even that is not a real issue, if done in a well-ventilated room (only 100 mg or so is used).

 

Ammonium bromide is non-toxic, practically speaking, but of course you should not eat it. Iron nails also are non-toxic but when you eat them, then you'll have a bad feeling afterwards, it is the same with most non-toxic chemicals.

 

Over here in NL, ammonium chloride also is used a lot in sweets. It is sold in the pure state as a white crystalline solid under the name 'salmiak'.

[Gilded]

Yeah, it's called "salmiakki" here. I had always wondered what crystalline ammonium chloride tastes like and a couple of weeks ago I had a few tiny crystals and I must say it's pretty strong stuff and it's understandable that it's often diluted to great degree.

[John Cuthber]

Since all bromides are toxic I really wouldn't recommend tasting them or inhaling the smoke.

[woelen]

I would call inorganic ionic bromides only marginally toxic (provided the cation is not toxic), but of course you should not eat them and also the smoke should not be inhaled. As I wrote before, even chemicals, which are not listed as very toxic, must be treated carefully, but I see this in the same line as other household items, which should not be inhaled, nor eaten.

Bromides like NH4Br, KBr and NaBr are not more dangerous/toxic than e.g. KNO3 fertilizer, soaps, common household solvents and so on.

[John Cuthber]

In terms of the LD50 and such the bromides are roughly as toxic as the chlorides but, since bromides are used as drugs acting on the central nervous system, I would sugest steering clear of them.

[Bluenoise]

I wonder if it's safe to taste ammonium bromide? It seems to be listed as more dangerous than ammonium chloride. Not that its taste probably differs much from NH4Cl.

 

I've never understood the obsession some pure chemists have with tasting chemicals.

Personally I chring even at the thought of tasting the tap water from my lab, eventhough it's obviously fine.

[woelen]

In terms of the LD50 and such the bromides are roughly as toxic as the chlorides but, since bromides are used as drugs acting on the central nervous system, I would sugest steering clear of them.

Of course, if you mean eating or inhaling them, then YES! But if you mean experimenting with them, then I say NO!

Bromides are quite safe for experimenting. Bromine is another matter.

[John Cuthber]

Quite a lot of chemicals are worth taking the trouble not to get on the skin too.

Of course, provided that you don't come into contact with the Br2 it's also safe for experimenting. All chemicals are safe as long as they aren't anywhere near you. (Explosive and radioactive ones can get you at a distance.)

Fundamentally, (and this is an important point) there are no dangerous chemicals. There are lots of dangerous things to do with chemicals and for some chemicals there's a bigger choice of dangerous things to do than others, but the danger is a matter of what you chose to do with them- not a property of the chemical itself.

A beaker of NH4Br isn't a bigger problem than a beaker of NH4Cl.

On the other hand, if I wanted to make some smoke I'd use the chloride unless I had a really good reason to risk the neurotxicity of the bromide (and possibly the carcinogenic bromate too)