alking
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Are there any practical methods to break an ethanol:heptane azeotrope in the home lab?
The title pretty much explains it all. I've got a solution of heptane and ethanol which I assume is 51% heptane:49% ethanol going by this azeotrope table on wikipedia. I am assuming it is not practical and will cost more than simply purchasing more solvent, but as I do not
currently have a use for such a solvent blend I thought it worth looking into, plus it may provide a good learning opportunity.
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ScienceHideout
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Couldn't you add water and do a simple extraction? Hexane is VERY nonpolar, and water is VERY polar. If you add water, the Ethanol will dissolve in
it, and the hexane should form a separate layer.
hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!
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alking
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That's a great idea, and much easier than distilling, thanks!
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Tsjerk
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If you don't get a strong separation or an emulsion, you could consider using brine instead of plain water. Although this will probably push some of
the ethanol into the heptane layer.
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alking
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Ok, now I have a follow up question; what if I want to recover both, is there a way that would not require boiling such a large amount of solvent? Is
there something I could add to the mix to help break the azeotrope during distillation I'm wondering? Doing a decent wash would be a lot of water I'd
then have to distill from and would take me quite a bit of time my largest boiling flask being 1L.
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