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Author: Subject: What happens when you mix hexane, water and chloroform?
alchemizt
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[*] posted on 16-3-2022 at 19:34
What happens when you mix hexane, water and chloroform?


I want to try this but haven't got around to it yet. I suspect adding chloroform first, pouring water on top, then hexane on top of the water will form 3 layers. What happens if you then shake the vessel?

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DraconicAcid
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[*] posted on 16-3-2022 at 21:05


Before you shake it, you'll have three layers. After you shake it, you'll have two layers- which one is on top will depend on the ratio of hexane to chloroform you use.



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[*] posted on 17-3-2022 at 10:08


Unless your hexanes/chloroform layer has a density almost identical to your water layer, in which case you'll end up with a cloudy emulsion that doesn't want to separate on an agreeable timescale.



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alchemizt
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[*] posted on 23-3-2022 at 22:16


Quote: Originally posted by DraconicAcid  
Before you shake it, you'll have three layers. After you shake it, you'll have two layers- which one is on top will depend on the ratio of hexane to chloroform you use.


In acid base extractions, I have seen many times that 3 layers form and no matter how much I shake it and mix it, the 3 layers just reform themselves. I've never tried this with pure water, does it work differently? If the two organic layers mix into one, can you separate them again by adding salt?

[Edited on 24-3-2022 by alchemizt]
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[*] posted on 24-3-2022 at 00:48


What you are seeing is a base that is not that soluble in the apolar solvent. When this happens you will see three layers, usually a bottom water layer, a middle base layer and a top apolar layer. Although I have also seen it when using DCM, where the lower layer was the apolar one.

You can prevent this by using a more or less polar solvent, to better match the base to be extracted, or just more solvent.


[Edited on 24-3-2022 by Tsjerk]
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