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From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: net.med
Subject: Re: Re: prevention of hangovers
Message-ID: <743@kitty.UUCP>
Date: Thu, 23-Jan-86 09:49:57 EST
Article-I.D.: kitty.743
Posted: Thu Jan 23 09:49:57 1986
Date-Received: Sun, 26-Jan-86 04:15:24 EST
References: <3122@sdcc3.UUCP> <587@scc.UUCP> <457@mhuxl.UUCP> <1198@princeton.UUCP> <683@ttrdc.UUCP>
Organization: Recognition Research Corp., Clarence, NY
Lines: 30

> C'mon, is it REALLY impossible to get chemically pure ethanol?  I have heard
> that it can't be had from distillation of a mix of it and water, at least not
> in "ordinary" equipment, but couldn't it be chemically synthesized "dry"
> (chemists?).

	It's not impossible to get 100% (200 proof) ethanol which is reasonably
pure - it's just difficult.  Pure 100% ethanol is VERY hygroscopic, and will
absorb water wapor from the atmosphere.  If you leave it thus exposed to the
air, you will eventually have 95% ethanol.
	Further complications result from the fact that when ethanol is mixed
with water and boiled (as in distillation), an azeotropic mixture is formed
at a concentration of 95% ethanol.  This means that continued distillation
will NOT result in ethanol concentrations greater than 95%.
	In order to remove the water, something must be mixed with the ethanol
which will displace the water.  The problem then becomes one of separating this
new substance from the ethanol.  This new substance may then leave impurities
in the ethanol.  Then you have to remove these new impurities.  And then if
you are bound and determined to have 100% ethanol, these procedures have to
be conducted in an atmosphere inert of water wapor.  Ain't easy.
	Actually, there are very few laboratory procedures and syntheses where
95% alcohol and 5% some_other_alcohol_which_displaces_water is unsatisfactory,
so there is no big demand for 100% pure ethanol - except for people bent upon
drinking it :-).

==>  Larry Lippman @ Recognition Research Corp., Clarence, New York        <==
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