Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!maverick.ksu.ksu.edu!kuhub.cc.ukans.edu!mcginnis From: mcginnis@kuhub.cc.ukans.edu Newsgroups: sci.electronics Subject: Message-ID: <27626.2779de9d@kuhub.cc.ukans.edu> Date: 27 Dec 90 17:44:29 GMT References: <14169@mcdphx.phx.mcd.mot.com> Organization: University of Kansas Academic Computing Services Lines: 26 > > In article <1990Nov28.203618.7294@arcturus.uucp> graham@arcturus.uucp (Thomas D. Graham) writes: >> >> I have some methanol, but I suspect that it is >> contaminated with water. Could I simply take a small sample, say 2 oz, >> burn it and the remaining liquid is water?? Any ideas??? Thanks. > > If you put it in the freezer, wouldn't the water percipitate out as ice? Alcohol and water mix to form a solution with a lower freezing point than either substance by itself. I believe that the ratio that has the lowest freezing point is known as the "eutectic". If you have a non-eutictic mixture and cool it, you will see crystals precipitate out. If you have too much water these will be mostly-water ice crystals, if you have too much alcohol these will be mostly-alcohol ice crystals. Just before the last of the mixture freezes the remaining liquid will be a eutectic mixture of alcohol and water. You could do a rough purification to separate the water and alcohol by cooling the alcohol-water mixture and lifting out the frozed alcohol so long as you didn't let the temperature get too close to the eutectic temperature (and you were sure you only had a little water in the mixture). This would not be an efficient way to separate the two and probably would be less efficient than distillation... just buy some new alcohol.