Vexing
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cold compresses
I recently heard that both Ammonium Nitrate and Urea are used in instant cold packs. Does anyone know of an easy test to differentiate between them?
\"For every action there is an equal and opposite government program.\"
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Oxydro
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Usually the safety label on the cold pack. Barring that, heat it - Urea will be melting (or maybe decomposing!) about 35 C colder than AN melts.
"Our interest's on the dangerous side of things" -- Browning
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Vexing
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Edit: I found an easy test, melting and see if it produces Nitrous oxide.
[Edited on 27-5-2007 by Vexing]
\"For every action there is an equal and opposite government program.\"
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olmpiad
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I suppose you could crystallize the compound and compare the structure of the two possibilities to the structure that you got.
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Eclectic
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Is it an either/or thing or maybe BOTH urea and ammonium nitrate?
I've made a liquid garden fertilizer from a 50/50 mix, and it dissolved faster and got colder than either one alone and only needed about 15% water to
dissolve it all.
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Swany
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Check the pH of a solution containing them; urea is basic and ammonium nitrate is acidic.
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olmpiad
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| Quote: | Originally posted by Eclectic
Is it an either/or thing or maybe BOTH urea and ammonium nitrate?
I've made a liquid garden fertilizer from a 50/50 mix, and it dissolved faster and got colder than either one alone and only needed about 15% water to
dissolve it all. |
When it's something being applied to one's skin, extreme cold is not always the best.
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Vexing
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It is Ammonium Nitrate. I tested a solution with Phenolphthalein. Just out of curiosity, how common is Urea in cold compresses?
\"For every action there is an equal and opposite government program.\"
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olmpiad
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Ive never found it
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