nlegaux
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Separating B2O3, NaBO2, and Na2B4O7
I believe I made some B2O3/NaBO2 by decomposing Na2B4O7 with heat (I assume there is probably still unreacted Na2B4O7). Does anyone have any ideas on
how to separate them? I have looked into separating them based on solubility and reactivity, but haven't been able to find anything. I may be able to
recrystallize the mix to separate one of the compounds, but I am interested in a better way of separating them.
Thank you,
nlegaux
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DraconicAcid
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Your proposed reaction seems counter-intuitive to me. Do you have a cite for it?
If you were decomposing regular borax, you probably only drove off water of hydration.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Metacelsus
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1: Divide the mixture into two parts.
2: Heat one of the parts with sodium carbonate or hydroxide. This will give you sodium metaborate.
3: React the other part with acid. This will give you boric acid, which can be thermally dehydrated to boric oxide.
Also, this method would work starting directly from the tetraborate.
Trying to actually separate the mixture would be much harder.
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Texium
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If you're going for B<sub>2</sub>O<sub>3</sub>, get a disposable ceramic container and heat boric acid in it until it is no
longer bubbling and appears to be a thick, clear syrup. This hardens into a glass like mass of B<sub>2</sub>O<sub>3</sub> upon
cooling.
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mayko
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I have had good results with an aluminum soda can, at least of small amounts - it seems to stand up to the heat and it is easy to cut off afterwards,
leaving a glassy block of boron oxide without the ceramic residue that can get scraped up along with the product
al-khemie is not a terrorist organization
"Chemicals, chemicals... I need chemicals!" - George Hayduke
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nlegaux
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Separating B2O3, NaBO2, and Na2B4O7
I believe I made some B2O3/NaBO2 by decomposing Na2B4O7 with heat (I assume there is probably still unreacted Na2B4O7). Does anyone have any ideas on
how to separate them? I have looked into separating them based on solubility and reactivity, but haven't been able to find anything. I may be able to
recrystallize the mix to separate one of the compounds, but I am interested in a better way of separating them.
Thank you,
nlegaux
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gdflp
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You already posted the question here http://www.sciencemadness.org/talk/viewthread.php?tid=53356 Please don't double post.
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blogfast25
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What makes you believe that? Did you start from commercial borax - Na2B4O7 decahydrate?
If it's B2O3 you want, react a borax solution with HCl solution to get H3BO3 separating out (the Na stays in solution as NaCl). Dehydrate the H3BO3
with heat to get glassy B2O3.
[Edited on 8-12-2014 by blogfast25]
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nlegaux
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Sorry about the double post... I'm not sure how that happened (I didn't write the post more than once...).
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gdflp
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Sometimes that happens, it might be a glitch in the forum software.
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Bert
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Threads Merged
8-12-2014 at 16:33 |
nlegaux
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I started with OTC Borax, put it in a crucible, and put the crucible in a fire for several hours. I thought it would be a good way to make B2O3 (I
didn't want to use my HCl). I read that the Na2B4O7 would decompose into the B2O3/NaBO2 here ---> http://chemistry.stackexchange.com/questions/569/when-we-hea... I decided that even if it was incorrect, I might as well find out by trying it
(Borax is cheap).
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