ammonium fluoride NH3F

[chilled_fluorine]

I was thinking about ammonium fluoride recently, it's similarities to water. Anybody want to post some rumblings about it? What temperature does it decompose at, if it does? Could it exist as a liquid at atmospheric pressure? Would it make a good solvent for anything? How could I make it? Could I make it from ammonium chloride and something with fluorine? Any info appreciated, thanks!

[Moontanman]

I was thinking about ammonium fluoride recently, it's similarities to water. Anybody want to post some rumblings about it? What temperature does it decompose at, if it does? Could it exist as a liquid at atmospheric pressure? Would it make a good solvent for anything? How could I make it? Could I make it from ammonium chloride and something with fluorine? Any info appreciated, thanks!

 

 

Ammonium fluoride is similar to water?

 

http://en.wikipedia.org/wiki/Ammonium_fluoride

 

It sublimes when heated—a property common among ammonium salts. In the sublimation, the salt decomposes to ammonia and hydrogen fluoride, and the two gases recombine to give ammonium fluoride, i.e. the reaction is reversible:

[NH4]F ↔ NH3 + HF

 

It sublimes at 100c exactly how is it similar to water?

[chilled_fluorine]

Ammonium fluoride is similar to water?

 

http://en.wikipedia....monium_fluoride

 

 

 

It sublimes at 100c exactly how is it similar to water?

 

Well, I heard it is the only substance that can form a crystal structure with water, and that it has exceptional solvent properties in its liquid state. And it can become a gas at 100c, like water. Sounds similar enough to me.

[hypervalent_iodine]

You of course know the difference between sublimation and vaporization?

 

Additionally, ammonium fluoride is not NH₃F. The ammonium ion is NH₄⁺ (ammonia is NH₃), making the neutral salt of ammonium fluoride NH₄F.

 

I'm really not seeing many similarities with water.

• It's a salt, water isn't.
• Melting point of ammonium fluoride is reported to be anything from 100^oC to 160^oC, though it tends to decompose before it melts (water is stable into the thousands of ^oC).
• Not very soluble in alcohols and not soluble at all in ammonia; water is.
• When it sublimes, it exists as HF and NH₃, where as water just remains as water.

etc.

 

I did notice that they had similar crystal structures and that their bond distances were similar; outside of that, the chemical and physical properties are quite different. As a solvent it would not be useful, especially since it decomposes around or before its melting temperature. From what I've read, it's used for oil well acidification or turned into a more acidic relative (ammonium bifluoride) for glass etching.

[chilled_fluorine]

You of course know the difference between sublimation and vaporization?

 

Additionally, ammonium fluoride is not NH₃F. The ammonium ion is NH₄⁺ (ammonia is NH₃), making the neutral salt of ammonium fluoride NH₄F.

 

I'm really not seeing many similarities with water.

• It's a salt, water isn't.
• Melting point of ammonium fluoride is reported to be anything from 100^oC to 160^oC, though it tends to decompose before it melts (water is stable into the thousands of ^oC).
• Not very soluble in alcohols and not soluble at all in ammonia; water is.
• When it sublimes, it exists as HF and NH₃, where as water just remains as water.

etc.

 

I did notice that they had similar crystal structures and that their bond distances were similar; outside of that, the chemical and physical properties are quite different. As a solvent it would not be useful, especially since it decomposes around or before its melting temperature. From what I've read, it's used for oil well acidification or turned into a more acidic relative (ammonium bifluoride) for glass etching.

 

I heard that in its molten state, it makes a good solvent for halogens and other elements. Is that not true? The similarity i was thinking of was its solvent properties. I did notice the bond distance as well. Wow, the classic undergrad's mistake of forgetting the extra H in the cation. :facepalms:You of course know the difference between sublimation and decomposition?

[John Cuthber]

"I heard that in its molten state, it makes a good solvent for halogens "

I don't know whom you heard that from, but I think you should stop listening to them

http://en.wikipedia.org/wiki/Nitrogen_trichloride

http://en.wikipedia.org/wiki/Nitrogen_triiodide

\Are quite likely products from the reaction.

[chilled_fluorine]

"I heard that in its molten state, it makes a good solvent for halogens "

I don't know whom you heard that from, but I think you should stop listening to them

http://en.wikipedia....gen_trichloride

http://en.wikipedia....rogen_triiodide

\Are quite likely products from the reaction.

 

Wow, I really need to get a new source! And they say they are reliable...Hypervalent iodine, after someone says how to make this stuff, could you please delete this post? Don't want anyone getting hurt, and I don't know how.

[hypervalent_iodine]

We don't generally delete posts in threads unless they are obscene, irrelevant or spammy. I do have to question why you would want it?

 

Also,

 

You of course know the difference between sublimation and decomposition?

 

Yes, but I'm wondering if you do based on this:

 

Well, I heard it is the only substance that can form a crystal structure with water, and that it has exceptional solvent properties in its liquid state. And it can become a gas at 100c, like water. Sounds similar enough to me.

 

John beat me to the solvation issue. Asides from the intrinsic reactive properties of the compound, I would think that you also wouldn't have hydrogen bonding, which is where water gets a bulk of its solvation properties from. This would depend on whether it exists as NH_4⁺/ F^- or NH₃ / HF in its molten state (I actually don't know which is the case; perhaps John might). Regardless, a mixture of ammonia and HF would of course be nothing like water as a solvent either.

[chilled_fluorine]

We don't generally delete posts in threads unless they are obscene, irrelevant or spammy. I do have to question why you would want it?

 

Also,

 

 

 

Yes, but I'm wondering if you do based on this:

 

 

 

John beat me to the solvation issue. Asides from the intrinsic reactive properties of the compound, I would think that you also wouldn't have hydrogen bonding, which is where water gets a bulk of its solvation properties from. This would depend on whether it exists as NH_4⁺/ F^- or NH₃ / HF in its molten state (I actually don't know which is the case; perhaps John might). Regardless, a mixture of ammonia and HF would of course be nothing like water as a solvent either.

 

When I said "becomes a gas" I meant that the matter itself becomes a gas, not the NH4F in a gaseous state, that just sounds silly. Is it even possible for it to exist as a gas? I wouldn't think so, although i would love to be told otherwise. Sort of akin to candle wax becoming a gas when you burn it in air. Admittedly, that was a very ambiguous thing to say.

I would like it if you would remove this post (this is an edit, I think I meant this whole thread, we haven't said anything of real use, no offense, just provided potentially dangerous information) so none of those anarchy cookbook fools googles triiodide, comes here, blows themselves up trying what John implied was possible, and completely ruins my reputation, as well as damage that of this site. As far as the anarchist fools go, thats just another one of natural selection's plots to better our gene pool. Triiodide is one of those trigger words that seems to attract every idiot in the country.

Edited August 26, 2012 by chilled_fluorine

[hypervalent_iodine]

I don't think it's an issue, but since I'm involved in this thread, I'll defer to other mods.

[John Cuthber]

Anyone who wants to can Google nitrogen triiodide and find out how to make it. They are not very likely to come across this page.

However it's possible that someone will be interested in ammonium fluoride melts and find this page. If it tells then to be careful about adding halogens to the mix then it's beneficial.

[Phi for All]

!

Moderator Note

Upon staff review, no hazmat rules were breached. No deletion is necessary.

[chilled_fluorine]

Did I ever tell you guys about the guy from science madness who was melting HMTD in a glass test tube over a blowtorch with no safety equipment? Did I show you the pictures, and tell you WHERE he found out you could melt HMTD? Fine, don't delete it.

[hypervalent_iodine]

chilled_fluorine,

 

Firstly, if you want to debate mod note, do so via the report feature or PM.

 

Secondly, you've had two experienced chemists tell you that this thread presents no obvious danger to a passer by. We are mindful of people's safety here and you can rest assured that if anything in this thread did present a serious risk to inexperienced readers, we'd deal with it.

[mississippichem]

chilled_fluorine,

 

Firstly, if you want to debate mod note, do so via the report feature or PM.

 

Secondly, you've had two experienced chemists tell you that this thread presents no obvious danger to a passer by. We are mindful of people's safety here and you can rest assured that if anything in this thread did present a serious risk to inexperienced readers, we'd deal with it.

 

I think it is noteworthy that discussing, in theory, what might result from a dangerous procedure is very different from advocating that someone conduct said procedure. Also it's very different than giving explicit technical/logistical details on how to carry out that dangerous procedure.

[chilled_fluorine]

chilled_fluorine,

 

Firstly, if you want to debate mod note, do so via the report feature or PM.

 

Secondly, you've had two experienced chemists tell you that this thread presents no obvious danger to a passer by. We are mindful of people's safety here and you can rest assured that if anything in this thread did present a serious risk to inexperienced readers, we'd deal with it.

 

I already said I agree with you, I just prefer not having to see another Jack. If you think this is safe, fine, but there are people out there who will go out of their way to do dangerous things. The road to a dangerous place is occasionally more dangerous than the place itself.

Edited August 26, 2012 by chilled_fluorine

[John Cuthber]

Perhaps it's just me but I think that a fairly obscure material, like ammonium fluoride, molten and under pressure in the presence of one of the halogens is quite hazardous, but pretty unlikely to be the cause of injury to anyone who happens across this page on the web because most people won't have the materials to try it..

On the other hand, the aluminothermic reaction of something rather hygroscopic- say calcium sulphate- to produce a few products two of which are rather hazardous is a bigger problem.

 

If we were in the business of closing threads because they mentioned something that could be dangerous I think we would close this one

http://www.scienceforums.net/topic/68449-make-calcium-metal/page__pid__699182#entry699182

before bothering with one about NH4F.

[chilled_fluorine]

 

Perhaps it's just me but I think that a fairly obscure material, like ammonium fluoride, molten and under pressure in the presence of one of the halogens is quite hazardous, but pretty unlikely to be the cause of injury to anyone who happens across this page on the web because most people won't have the materials to try it..

On the other hand, the aluminothermic reaction of something rather hygroscopic- say calcium sulphate- to produce a few products two of which are rather hazardous is a bigger problem.

 

If we were in the business of closing threads because they mentioned something that could be dangerous I think we would close this one

http://www.sciencefo...182#entry699182

before bothering with one about NH4F.

 

John, you just can't let that go, can you? I try to enter each and every post without prejudice, a style I would reccomend to you. Why do you have to make it so hard? I was using SIX grams, ignited from many meters away. My crude tests confirmed a near anhydrous material. Does anyone here find that so terribly dangerous?John, I really want to be on good terms with you, could you please try?My main concern is not people successfully synthesizing a triiodide, the odds of that are quite low, it is them inhaling hot, gaseous HF.

[hypervalent_iodine]

The odds of which are also quite low.

[chilled_fluorine]

The odds of which are also quite low.

 

Agreed, but still existent.

[elementcollector1]

The odds of just about everything possible are existent. The probability, however, is as hypervalent said: Probably quite low. I do agree, however, that full safety protection should be used just in case; I've heard stories about HF. And they gave me nightmares.

[chilled_fluorine]

The odds of just about everything possible are existent. The probability, however, is as hypervalent said: Probably quite low. I do agree, however, that full safety protection should be used just in case; I've heard stories about HF. And they gave me nightmares.

 

There were some idiots on an anarchy forum who clearly had access to hydrofluoric, as well as ammonium chloride. Just saying...

[hypervalent_iodine]

I'm unofficially asking this to get back on topic.

[CaptainPanic]

Yes, let's get back on topic:

I was thinking about ammonium fluoride recently, it's similarities to water. Anybody want to post some rumblings about it? What temperature does it decompose at, if it does? Could it exist as a liquid at atmospheric pressure? Would it make a good solvent for anything? How could I make it? Could I make it from ammonium chloride and something with fluorine? Any info appreciated, thanks!

And since the MSDS (Material Safety Data Sheet) says about ammonium fluoride that:

 

The substance decomposes on heating producing toxic and corrosive fumes including hydrogen fluoride and ammonia.

 

According to another source, HF might even form when you expose the ammonium fluoride to water.

The same source says that the decomposition already occurs at >100C (which is, imho, a pretty low temperature).

 

 

As for safety of putting this kind of info on our forum - I just plucked that off the internet. It took me about 10 seconds to find it. The second source is from the manufacturer themselves. I'm sure that if you make millions of pounds per year, you do give it a little thought. Btw, they do not sell it directly to customers, only to industry.

[chilled_fluorine]

Yes, let's get back on topic:

 

And since the MSDS (Material Safety Data Sheet) says about ammonium fluoride that:

 

 

 

According to another source, HF might even form when you expose the ammonium fluoride to water.

The same source says that the decomposition already occurs at >100C (which is, imho, a pretty low temperature).

 

 

As for safety of putting this kind of info on our forum - I just plucked that off the internet. It took me about 10 seconds to find it. The second source is from the manufacturer themselves. I'm sure that if you make millions of pounds per year, you do give it a little thought. Btw, they do not sell it directly to customers, only to industry.

Would HF and ammonium chloride work? It would probably make some nasty fumes, but it seems like it should work. I still cringe every time I open that bottle.I was just about to point out what a runaway forum this has become, should we move it to the lounge?

What company was it? I know someone who owns some sort of PCB etching place, I could probably get it through her. Why she chose this profession? No idea, but it is a convenietnt source for corrosive things, except sulphuric, she doesn't use that.