EtAcH2OMeOH
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Three solvents miscibility
Hello everyone, first time poster, long time lurker.
I wondered if a weak base dissolved in 90% MeOH and 10% water could be extracted withouth removing the MeOH (as to avoid the distillation setup). As I
didn't know if a solution of EtAc (or any other [almost]nonpolar solvent), MeOH and water were readily soluble I searched for it and ended up trying
to understand some ternary diagrams, but as I wasn't getting anything clear out of them I've come here to ask you:
Are they miscible?
Would increasing the ionic strength of the solution reduce the solubility of the nonpolar solvent?
If there was any solvent inmiscible with methanol (don't know of none) the solution could also be dried, filtrated and extracted.
Any further ideas?
If you require any papers with data about this I may be able to provide them (as long as it is not any copyright infringment).
Thanks for your time and sorry if there are grammar mistakes.
[Edited on 12-1-2013 by EtAcH2OMeOH]
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barley81
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Ethyl acetate is an ester, so it is polar. It's also miscible with methanol, so I would expect it to be highly soluble in 90% methanol/10% water, if
not completely miscible.
Dissolving salt or some ionic substance in your solution would indeed reduce the solubility of a nonpolar substance, such as ligroin or hexane. Hexane
is immiscible with methanol, so you may be able to use for extraction it if your compound is very soluble in it.
It would also be of help if you identified the compound (or kind of compound) you are trying to extract. You said weak base, so is it an amine? You
must check its solubility data to determine whether extraction can work.
Whoops, ethyl acetate should be MEK, and ester should be ketone. It was late at night.
[Edited on 13-1-2013 by barley81]
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Nicodem
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EtAc is a shorthand abbreviation for methyl ehtyl ketone aka MEK. The shorthand for ehtyl acetate is EtOAc.
EtAcH2OMeOH, you do realize that your question is unanswerable due to the lack of the most basic information? Please read the forum guidelines.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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DJF90
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I've heard of someone doing a phase separation/extraction using Methanol. The issue is to load up the aqueous phase with enough inorganic salts.
Similar can be said for THF, though commonly 1-2vol of diethyl ether is added (relative to THF used) to effect the phase separation.
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DieForelle
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While this is up, a somewhat related question.
I know the hygroscopic nature of alcohol means it is used for fuel line water removal; i.e., it makes the water miscible enough with the aliphatic
hydrocarbons that all 3 of them get pulled through the fuel system and engine.
BUT...and this will seem really stupid, probably, but remember I got an A in college level org. chemistry before many of your were born and have
forgotten most of it...does it sort of "work the other way". In other words, let's compare pure EtOH in a loosely sealed container, and a double
volume of a 50/50 mix of EtOH and hexane in an exactly similar container. So in other words you have 2 exactly similar molar qts. of alcohol, one is
just mixed with hexane. If you did a Karl Fischer titration 3 months later (don't these precisely determine amt. of water present? ) would the hexane
mix have absorbed less water from the air, on a per unit alcohol basis of course. In other words does the hexane somehow repel water from the
alcohol?
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