tritium
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sodium borohydride analysis of activity
ladies and gentlemen,
I was wondering whether you are aware of an analytical technique that allows me to test a sample of sodium borohydride, NaBH4 for its activity
(quality).
Though being manufactured and sealed in 2004, its lumps and should be a powder IIRC. A fellow chemist claimed it might have decomposed to NaBO2 and I
would like to know before i buy.
Theres instrumental analytical equipment available to me but i cannot think of or find a method.
thanks in advance!
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Lambda-Eyde
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Decomposing it in aqueous solution and volumetrically measuring the hydrogen evolved is the standard method, IIRC.
Edit: I don't have any sources, but I have a strong recollection of reading that somewhere.
Can someone verify it by providing sources, or is someone perhaps disagreeing with me?
[Edited on 23-3-2010 by Lambda-Eyde]
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arsen
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You are right, volumetry is a typical procedure for alkali metal hydride, due to its simplicity and reasonable accuracy. That's usually how they assay
hydrides.
Quote: Originally posted by Lambda-Eyde  | Decomposing it in aqueous solution and volumetrically measuring the hydrogen evolved is the standard method, IIRC.
Edit: I don't have any sources, but I have a strong recollection of reading that somewhere.
Can someone verify it by providing sources, or is someone perhaps disagreeing with me?
[Edited on 23-3-2010 by Lambda-Eyde] |
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mr.crow
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Time to bring up an old-ish thread.
How about adding the NaBH4 to a stoichiometric amount of dilute HCl and using an analytical scale to measure the before and after. That way you know
how much hydrogen escaped.
Would that work?
Double, double toil and trouble; Fire burn, and caldron bubble
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Magpie
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Perhaps a redox titration as I show in my recent post on assaying sodium dithionite might work:
http://www.sciencemadness.org/talk/viewthread.php?tid=11785&...
The single most important condition for a successful synthesis is good mixing - Nicodem
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mr.crow
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I'm not sure how titration would work. The problem is it decomposes by itself in water and might reduce the indicator!
Measuring hydrogen volume sounds good. I'm not sure how I would assemble the apparatus so all the gas gets measured and not stuck in the tubes.
I would have to measure the mass accurately at the University anyways, so my method sounds like the easiest.
Double, double toil and trouble; Fire burn, and caldron bubble
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