anticoplanar
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HOWTO: Make Sterno/Jellied Alcohol
Today I made jellied alcohol and it was a real treat. I was hoping someone might be able to tell me the mechanism?
I added 10ml of a saturated solution of CaOAc to 30ml of Ethanol, it immediately solidified into an alcohol jelly.
I can't wait to fill up cans with it for camping 
Edit: Any ideas on a procedure for making the acetate from Calcium Carbonate - chalk/egg shells/marble and vinegar? It should be pretty
straightforward. I stupidly tried marble and acetic anhydride.... and I'll tell you.. it didn't dissolve at all, and the stuff is nasty.
[Edited on 29-3-2007 by anticoplanar]
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Magpie
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Calcium acetate is easily made from vinegar and slaked lime [Ca(OH)2]. I have purchased lime by the pound dirt cheap at a weed & seed place.
Just react, evaporate, and dry. I'm not sure if you end up with a hydrate or not and how hot you might have to go to get anhydrous Ca(OAc)2.
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It should be pretty straightforward. I stupidly tried marble and acetic anhydride....
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Cringe...wince....
[Edited on by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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UnintentionalChaos
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There are plenty of people here who would start hitting you over the head with the nearest blunt object for wasting Ac2O. If you added some water, it
would start reacting as acetic acid formed, but that seems a terrible waste of acetic anhydride. Since acetic acid is so weak, it stands almost no
chance against solid chunks of anything. I used distilled vinegar and freshly precipitated CaCO3 to make some once. CaCl2 + Na2CO3 -> CaCO3 +
2NaCl. The carbonate settles and the liquid is decanted. The solid is washed several times and added to vinegar, which fizzes for a LONG time
(intermittent shaking helps). When dehydrating the stuff, it will creep up the sides of the container and refuses to follow logic and ppt any crystals
in the solution. It is also very prone to decomposition and you need to dehydrate in an over well below its decomp temperature (160C) otherwise lots
of it turns to CaO (which becomes apparent when you try to dissolve it, the Ca(OH)2 forms and refuses to dissolve appreciably). Generally, calcium
acetate is the monohydrate, and given that you crystallized it from water, it will probably be the monohydrate (you can always leave it out for a
while just to make sure, though if all you want is a saturated solution, just keep adding it regardless of hydration level.)
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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anticoplanar
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I know it is a mortal, mortal, evil sin. At the very least it was a good introduction to the substance... which seems to have some very strange (to
me) and interesting properties. Comments?
Thanks.
Anti
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Glaudge
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total necro-post, but i have plenty of Ca acetate that i made by pulverized limestone-vinegar and re
crystallized a time or two, it has set in front of our heating stove for a while, its got white chunks that are as hard as a rock, with no noticable
crystaline structure.
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chemrox
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I didn't see CaO and acetic acid mentioned. Could one get a less hydrated form using these? [BTW- using marble and Ac2O to make your own Sterno is a
little like distilling $50 Tequila to get lab ethanol isn't it? Come to think of it, what did you use for the alcohol?]
Now to the real followup questions: does the CaOAc approach work with higher alcohols like IPA? And he asked what the mechanism was? Does anyone
know? What is Sterno? why is it a gel? Does CaOAc gel gasoline as well?
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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