regioselective13
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A.N. or Urea?
Hey everyone, I have a question and I'd appreciate your input. I want to perform a synthesis of hydrazine sulfate, as is written up in the
prepublication forum. I'm almost ready to do the synthesis, but I still need to get some urea. So, i went down to Walgreens and bought this instant
cold pack
http://www.walgreens.com/store/c/walgreens-instant-cold-pack...
as I had heard that most cold packs found in stores now a days contain urea and not ammonium nitrate. When I got home I decide to check its MSDS just
to be sure, but I could not find it. I stumbled across a SM thread that mentioned that the cold packs found in Walgreens usually work well for
nitrations, meaning they must be ammonium nitrate. So, the question is: how do I figure out what I have? After opening the instant cold pack and
examining the contents, it was found that the solid component consisted of white pellets. I heated a portion of these pellets and observed that they
soon melted and started fuming, and the color of the liquid mass was slightly yellow, possibly due to impurities. The idea then came to me to add
nitric acid to a small amount of the substance, as I had read that the formation of urea nitrate is quite exothermic. The addition was indeed
exothermic, but when I added the same amount of nitric acid to an equal portion of ammonium nitrate the release of heat was comparable, meaning this
test doesn't really get me anywhere. I would appreciate any suggestions you guys have for me.
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Sulaiman
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I guess one easy test would be melting point,
Urea 133 to 135 C and ammonium nitrate 169.6 C
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bismuthate
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I would try adding AgNO3 to a solution of the cold pack powder. If it precipitates AgCl then it's probably NH4Cl.
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Bot0nist
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Sorry of this is obvious, but check the packaging really well. All of the cold packs I have encountered have been labeled. Either ammonium nitrate,
urea, or calcium ammonium nitrate.
The NH4NO3 variety I've seen is usually pure white prills. The others look much more dirty and yellowish or very "off" white.
Bismuthate, you mean ammonium nitrate as opposed to ammonium chloride, right? Or am I confused again.
[Edited on 5-6-2015 by Bot0nist]
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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bismuthate
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Oh sorry. I though most cold packs had ammonium chloride in them nowadays due to explosive worries.
I wasn't thinking.
.
[Edited on 5-6-2015 by bismuthate]
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UC235
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Mix a bit of the unknown as a solution with cold NaOH solution. Ammonium nitrate should have an immediate and strong smell of ammonia, while urea
shouldn't
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bismuthate
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http://www.sciencemadness.org/talk/viewthread.php?tid=17529
I believe that urea and NaOH makes NH3 too.
http://www.scienceforums.net/topic/38367-what-happens-when-y...
I'm not sure though.
[Edited on 5-6-2015 by bismuthate]
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Oscilllator
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Urea does hydrolyse to ammonia under basic conditions (I have done this) but it is quite slow at lower temperatures and so if you use cold water like
UC235 suggested, you should be fine.
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regioselective13
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All right, I'm pretty sure what I have is A.N.
Sulaiman, I don't have a Mel-Temp so I wasn't able to get an accurate melting point reading, but at around 160 degrees only a portion of the mass had
begun to melt, and the rest was intact; this seems like it would disqualify urea as being the mystery substance.
bismuthate, I don't have any silver or silver compounds available so I couldn't perform this test.
Bot0nist, I double-checked the package and I couldn't find any information as to its ingredients.
UC235/Oscillator, I added a cold solution of NaOH to a small portion of both ammonium nitrate and the unknown compound, the release of ammonia was
practically identical.
I do have one more question, and that is why, after heating the substance and letting it cool, it took on a darker color as if it was charred? Is this
due to additives of some kind, or is it because I might have calcium ammonium nitrate rather than straight A.N.?
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blogfast25
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Funny that: the OP didn't not express even the slightest concern about NH4Cl! You sure you're replying to the right thread? 
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CuReUS
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that's definitely AN. that's exactly how it was described in a Shake-n-bake meth cook book.The author of the book instructed to look for "white
pellets" in the instant cold packs.
but this is a silver lining to the whole thing.Instead of using urea,make NH3 using the pellets,and then do Nurd rage's
hypochlorite-ketazine process.Its much better and elegant than hoffman on urea
https://www.youtube.com/watch?v=UB7vwIFCnR0
https://www.youtube.com/watch?v=FDG3ne_VaXU
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Texium
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Ha, I really hope your joking about the fact that it's white
pellets being proof that it's ammonium nitrate since a urea one would contain identical looking white pellets.
The quick formation of ammonia that the OP describes is sure proof though. Urea doesn't react with NaOH fast enough at cool temperatures to produce a
smellable amount of ammonia in a short time, although the reaction speeds up a lot at higher temperatures. I use urea for making my ammonia because I
can't find any clean stuff OTC. I'm thinking I'll try out my new gas dispersion tube tomorrow. Should improve the yield and concentration of the
ammonia solution.
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binbin
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I have opened cold packs of Urea and they were white pellets too. Heh, how can you possibly state that white pellets mean they are Ammonium Nitrate?
Here in Canada I searched up and down for months for cold packs containing Ammonium Nitrate, and came up short every time. In the end, I opt'd for
using Potassium Nitrate as a substitution for my experiments.
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kecskesajt
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Add conc HCl to it and then add copper pieces to it.If it produces nitrogen oxides, it is a nitrate salt.
DO IT OUTSIDE!!!
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