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Author: Subject: Impure Acetic acid
chloric1
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[*] posted on 11-1-2004 at 14:59
Impure Acetic acid


I have purchased some Acetic acid about a couple of years ago and I never really tested its strength or purity becuase I was using it to patina copper and to make copper acetate. Well when I had my acetamide synth failure, I put some of the "Glacial" acid into the freezer and to my horror it would nt freeze even though it was cold enough to freeze pure water! I realized I had crap. I have sinced consulted Langes handbook and there was no mention of an azetrope with water so I decided a simple boiling was in order. Today I boiled and measured the temperature to find that when it finally started to boil it was at 128C!! I did this until my original 68 grams of acid became 11 grams and still does not freeze. :mad:
Next I was considering dissolving anhydrous MgSO4 in the stuff and distilling. Any of this sound familiar to anyone? I mean it smells like acetic acid, it makes good copper acetate but its melting and boiling properties dont jive. May just search for a more reputable source of CH3COOH soon. Thanks for any information or experiences.




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ech310n
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[*] posted on 11-1-2004 at 18:29


Taking a look at an old MSDS I have, Glacial Acetic Acid (99% Acetic Acid) has a boiling point of 118*C though the melting point stated is 16*C so I have no idea. I hope this helps anyway.

EDIT: I do not know if you have the equipment to do this but you could try a titration: http://members.tripod.com/~frakir/titrate.htm

[Edited on 12-1-2004 by ech310n]




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chloric1
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[*] posted on 11-1-2004 at 18:58
titration


I have yet to purchase burets but I should get some soon because I need to validate acid and base strenghth before use. I have found on a photography supply company the ability to purchase the acid at $9 per litre. I have delt with them before and I think they would sell me a quality product. I want the Glacial acid because I have discovered that it is a useful solvent in organic synthesis. I could use my more impure product for permanganate oxidations where a water/acetic mixture would be advantageous, otherwise the impure stuff will be used for metallic acetates.



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