JJay
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What is in Walgreen's Instant Cold Packs?
I recently obtained some instant cold packs from Walgreen's. The contents were not listed on the package, but I had read some online sources on other
forums stating that they were ammonium nitrate and an unusually pure source of it.
I removed the prills from the pack and found them to be a dirty white color, smelling of ammonia. That's pretty consistent with what many people have
reported that ammonium nitrate looks like, but I've also found several reports stating that Walgreen's instant cold packs do not contain ammonium
nitrate or that they contain it mixed with other substances.
Several brands that are available locally state that they contain ammonium nitrate on the package (and of course I could just buy it). But does anyone
know offhand what is in Walgreen's cold packs?
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Amos
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It's ammonium nitrate. I use them to prepare concentrated ammonia by reacting them with sodium hydroxide. I generally use excess sodium hydroxide in
the process, and then treat the finished reaction mixture with dilute nitric acid to make sodium nitrate as a byproduct.
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JJay
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I thought so... I think I'm going to use them to make nitric acid and save my potassium nitrate since it is harder to find.
Now if I can just find some relatively pure urea... I found it locally as an ice melt, but according to the label it is contaminated with propene (??)
and a blue copper cyanate pigment that I suspect will be hard to completely remove by recrystalization.
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macckone
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Cold packs are almost universally either ammonium nitrate or urea. Urea can also be found as a component in fertilizer. Ammonium nitrate can as well
but it is always contaminated a wide range of 'crud'.
The urea ice melt has a coating on it that is the propene crud. And the blue copper cyanate is dispersed through out. Yes the blue stuff is next to
impossible to remove. A good way to remove it MIGHT be to add sodium bicarbonate but that might just be another way to add more unwanted ions to the
mixture.
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UC235
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I have never managed to get rid of the blue dye. It even seems to co-crystallize out from boiling denatured alcohol. Or enough makes it into the
crystals to stain them, at least. I bought 5lbs of clean urea from ebay and used the blue stuff as fertilizer.
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unfrozen
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Look for "diesel exhaust fluid" at your auto or hardware store. I looked at the MSDS for the fluid at Menards and it says urea and water.
http://www.menards.com/main/tools-hardware/automotive-marine...
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cyanureeves
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http://www.fertilome.com/product.aspx?pid=4417c335-6984-49ad... it is a little bit off white color but when it is recrystallized it makes
beautiful shards.
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MrHomeScientist
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I can also confirm Walgreens instant cold packs are ammonium nitrate. I've made both concentrated ammonia and nitric acid from this material, after
dissolving in water and filtering off some insoluble impurities (floating crud, probably anti-caking agents). If you check the label these things
always (in my experience) say "Contains: ammonium nitrate" or "Contains: Urea". I believe WalMart is in the urea camp, now.
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JJay
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According to Walmart.com, the red Equate brand instant cold packs contain calcium ammonium nitrate. Locally, only the blue Equate brand packs were
available a few days ago, and they state that they contain ammonium nitrate. Certain other cold packs on Walmart.com do contain urea but I didn't see
any of them on the shelves here (probably sold out), and I don't see the blue packs on Walmart.com. So I think the ingredients in Walmart brand cold
packs vary.
Walgreen's is the only brand of cold packs I have found that does not list the contents on the package.
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Magpie
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This may not be practical for some but I bought a 50 lb bag of urea at a weed & feed store for $10 some years ago. I use it mostly as a de-icer
on my sidewalks. But when I have needed some for my chemistry it has worked very well. It is mostly pure but I recrystalize it using denatured
alcohol before use using the procedure in Prepublication.
The single most important condition for a successful synthesis is good mixing - Nicodem
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(UH) Stacked
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Crappy Nitrate IMO
size1 The cold packs from whal-Greens suck in my opinion
If you want better nitrate i would suggest going to a Rightous-Aide for *8 packs of instant cold packs. The prills are decent in size and are pure
white, ( im guessing its cleaner than that brown moist wal-greens and wally worlds calcium AN crystals.
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JJay
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I ended up getting some urea from eBay. Walgreens has 8 packs of cold packs too. The ammonium nitrate from them looked like it might have some dirt in
it, but I am not very concerned about it since I plan to use them simply for making nitric acid.
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(UH) Stacked
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Quality Check
So is the AN better when the prills are actually snow white? or is it "purer" when its that dirty heroin HCl color?
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JJay
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I don't know.... Pure ammonium nitrate should be snow white. But not everything that is snow white is pure ammonium nitrate.
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