EmmisonJ
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how quickly does glacial acetic acid breakdown if kept in original container...
if GAA has been used before but was recapped immediately and stored in its original container at room temperature, does it have a short storage life?
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DJF90
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I dont see how GAA would break down. It might absorb atmospheric water but so long as you keep it tightly capped then this shouldnt be a problem.
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Sauron
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I concurr. GAA is as oxidized as it can get, so how is it supposed to "break down"? whatever that means anyway.
Sitting in its original container it isn't going to turn into ketene.
It isn't going to spontaneously reduce to acetaldehyde or ethanol.
If it takes on some water from the air, shame on the bottler, but just dry it and redistill per the standard procedures in the usual texts
(Purification of Laboratory Chemicals) and the GAA is as good as new. Not one molecule of acetic acid will have "broken down" - it isn't a Yugo.
Sic gorgeamus a los subjectatus nunc.
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vulture
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| Quote: |
GAA is as oxidized as it can get |
Not entirely correct, but for all practical purposes, GAA does not show any air induced oxidation. Just pointing this out to prevent some loon from
mixing GAA with chromic acid or, heaven forbid, Mn2O7, just to prove you wrong.
[Edited on 24-2-2009 by vulture]
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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EmmisonJ
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thanks guys, i know i can always count on this board on clearing things up 
it's something someone told me (misinformed me apparently) via word of mouth and i wanted to see what the pro's had to say about it
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chemrox
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Well .. not quite. I have no idea how long because it depends on humidity of where it's kept and how long the cap is off at a time and how many times
the cap comes off in a year but GAA stops being GAA and becomes AA eventually. It does not 'break down' as has been mentioned; at least not in
practical terms. @Vulture: what happens when you put CrVI in it? I just about ran down the hill to see for myself.
"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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Sauron
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The thread poster is talking about the stuff auto-oxidizing or otherwise undergoing chemical change. He is not talking about taking on water. GAA and
95% acetic acid are chemically same. One is just anhydrous. Dry the wet Aa and it is GAA again.
Nor is he talking about throwing in Cr(VI). Of course yoiu can chew it down to C and CO and CO2, where do you reckon the carbon on filament of a
ketene lamp comes from if you are burning GAA in it?
So no, my remark was not "wrong" by the conditions stated. You can't impose a massive shift in the premise like that.
CH3COOH left alone in glass is going to remain CH3COOH.
Elves are not going to add chromic acid in the wee hours of the morning.
[Edited on 24-2-2009 by Sauron]
Sic gorgeamus a los subjectatus nunc.
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Sedit
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Put it this way EmmisonJ the one thing that annoys me about carboxylic acids is there stability, If they would just decompose on the fly I would be a
happy man.
Do a search and see if you can find a way to chemicaly reduce them down to an alkyl chain and report back... that will pretty much answer your
decomposition question.
~Sedit
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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PHILOU Zrealone
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| Quote: | Originally posted by Sauron
It is not even flammable. That ought to tell you something.
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-With a flashpoint at 40°C, I doubt it to be "not even flammable". After all it is roughly equivalent to an equimolar mix of CH4 and CO2... so
flamable but tempered by the CO2 moiety... (CH3-CO2-H vs CH4 + CO2)
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Sauron
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Ah, you are right. I wonder what I was thinking of.
Sic gorgeamus a los subjectatus nunc.
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