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Author: Subject: Seperating a Mixture of KOH and K2CO3
cpman
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[*] posted on 10-12-2013 at 19:09
Seperating a Mixture of KOH and K2CO3


Hello everyone!
Recently, I realized that I have a mix of solid KOH and solid K2CO3. I used it for an aeroponic plant propagation chamber to adjust the PH.
I know that both of these are really useful reagents, and I'd like to know a way to seperate them, as I have no bases aside from CaCO3 and NaHCO3. Neither of my current bases are very strong, and neither can compare to KOH.
Do any of you have an idea of how I can seperate these two salts?
The mixture contains nothing but KOH and K2CO3.
Thanks!
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bismuthate
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[*] posted on 10-12-2013 at 19:38


KOH is soluble in ethanol K2CO3 is not.



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Metacelsus
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[*] posted on 10-12-2013 at 19:48


Fractional crystallization, maybe? This would be hard, because their solubilities are pretty similar, according to Wikipedia.

If you want relatively pure KOH, you could heat calcium carbonate to decompose it to CaO, then dissolve it in water (it's soluble, but not very) and mix it with your potassium hydroxide/carbonate solution. This will precipitate calcium carbonate and leave you with KOH in solution.

Bismuthate's ethanol idea is also a good one.

[Edited on 11-12-2013 by Cheddite Cheese]




As below, so above.
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cpman
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[*] posted on 10-12-2013 at 20:06


Thanks so much!
I think I'll try the ethanol solution.
Thanks again!

Well, now I know what to do this weekend...
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Panache
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[*] posted on 18-12-2013 at 02:26


I have a paper! I is available with just a single click.

Attachment: Carbonate removal from concentrated hydroxide solutions.pdf (199kB)
This file has been downloaded 362 times




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[*] posted on 18-12-2013 at 23:09


Thanks for that PDF. I'll might make some CaO for this.
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