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Specialty Chemistry Forums => Citizen Chemist => Topic started by: damib on March 20, 2017, 11:11:23 AM

Title: freezing of alcohol+water and fractional freezing
Post by: damib on March 20, 2017, 11:11:23 AM
Hello,
today i had an argument with my friends as we spoke about making of eisbock beer. To put it easily. I say that it is possible for the water to freeze quickly in homogenous solution of alcohol+water than the alcohol. My friends say that it is impossible and homogenous solution has exact temperature for melting so no compound cant freeze quickly in homogenous solution of alcohol and water. Considering to my experience i think that if you put alcoholic drink in freezer, you can see small crystals od ice in it, but i am not absolutely sure. I am also interested in how such solution freezes. I imagine that that water is first to freeze and then the alcohol is freezing until both compounds reach some point of equilibrium of solidness so then then the solution seems solid.
Thank you all for your opinion on this interesting topic
Title: Re: freezing of alcohol+water and fractional freezing
Post by: Arkcon on March 20, 2017, 12:18:39 PM
Fractional freezing is a process that exists.  Its used to purify things, from eisbock, to schnapps, to silicon for solar cells.  https://en.wikipedia.org/wiki/Fractional_freezing  It can be used to separate things with different freezing points, and it can fail, freezing everything together if done wrong.  You've put enough ifs, buts and other qualifiers in your missive, that we can't really answer better than that.  Try splitting up your question into shorter ones, read Wikipedia, and compare what your read to what you see and know.
Title: Re: freezing of alcohol+water and fractional freezing
Post by: Enthalpy on March 26, 2017, 01:35:35 PM
The answer to the complete question happens to be there
https://en.wikipedia.org/wiki/Fractional_freezing#Concentration_of_liquids

The limit to the separation of water from ethanol by freezing is the eutectic, but at 94% ethanol already
https://commons.wikimedia.org/wiki/File:Phase_diagram_ethanol_water_s_l_en.svg