The Vespiary
The Hive => Chemicals & Equipment => Topic started by: ADDkid on December 16, 2003, 01:46:00 AM
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I am trying to make glacial acid from sodium acetate, but have a problem. When I added the sodium acetate to sulfuric acid, and distill, I get a fix boiling point of 105c I was wondering if perxoxyacetic acid was form, since that is the boinling point of that chemical.
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Concentrated Acetic Acid is called Glacial because of the wonderful cristalls which forms at 16°C (when waterfree).
Destillation is a possible way to purify Acetic Acid. It will come over at 117-118°C at Po.
To get the free Acid from a salt like sodiumacetate u need a stronger acid wich will form a sodiumsalt and the acetic acid.
A good sodiumsalt is sodiumchlorid and therefor HCl is a good choice. Now we need the right amounts of the educts. A satturated sodiumacetate solution is acidified to pH 3,5 and destilled. Use a good vigreux (40-60cm at 500ml flask) to distill fractionated. Azeotropic mixtures with water will boil lower. Another way to purify acetic acid is to crystallize it from the solution at 1°C. The crystallized Acid will be very pure but not easy to handle (except in canada).
Another workable method is the oxidation of Acetaldehyd at the air to Acetic acid. This method is used industrial and is also usable in labs.
But the best and easiest way to get pure acetic acid is to go to moms old fashioned super market around the next corner and buy some 50% acetic acid and purify it with crystallisation.
Peroxo group can be formed in oleum (conc sulfuric acid) but will never be formed in this reaction. it ll be a n azeotropic mixture thats boiling at 105°C.
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Thanks for the help, but all that you have mention swig knows, I finally after many sulfuric acid distills got it at about 110C, I would like to know the purity of that, I have good lab eq, but the bitch keeps coming over at 110c, I said fuck it and used that purity to make acetamide from urea. So far so good I think, the room smells like cat piss. ::)
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corner, carries only 8% max. vinegar and the photoshop citric acid instead of acetic acid as stopbath.
Here where I am.
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i dont know why peroxy would form in H2S04/Na0Ac, as peroxyacetic is a strong oxidizer and sulphuric acid is a weak ozidizer, especially if it was not exposed to atmospheric 02 for a long time.
if there is some residual water in the acetic distllied from h2SO4/Na0Ac perhaps using a dessicant (like anyhd MgS04)would remove it.
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I believe your problem is from residual water in your H2SO4. You need to use at least 96% H2SO4.
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Is it better to just buy it, or is the risk not worthwhile. Also, swig is having problems finding a drying tube, how could swig get one, I need to get absolute alcohol. and since swig is on the subject was is the precent content of absolute alcohol, it can't be 100%
ADDkid
P.S. I got it with a real fucking slow fract. distillation. Also that 105c temp, I reported was when I extracted with toluene. Also some more good information is that a pure compound can be received when a third compound is added. For example, methanol is added to give a better yield on ethanol. The azeotrope comes out first followed by the pure compound.
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Acetic acid/Toluene 100.6deg 28.1% 71.9% is the azeotrope.
Just buy the stuff. It's cheap and easily available and not suspicious at all. I picked up a 22 liter jug of the CP grade 99.92% glacial for $96. I spent more money on electricity trying to distill the shit than it costs.
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Absolute ethanol is available, it is not denatured, and it is dehyrdrated, it is marketed in the USA, as 200 proof ethyl alcohol. Which corresponds to 100% ethyl alcohol. There is no other alcohols present in the product, i.e. denaturing agents such as methanol, or IPA.
Good luck my, attention defficient friend.
methyl_ethyl