Sciencemadness Discussion Board

Is my NaBH4 legit?

SHADYCHASE54 - 4-2-2011 at 18:12

Let me first say I am sorry for starting a new topic on what is probably an inane question. I recently bought an item from a supplier that I have come to trust, but I am a little worried that the NaBH is crap. I sprinkled apout 0.25g in H20 and initially nothing however, after about ten seconds I noticed effervesence. Is this typical? Also would anyone be willing to offer a couple suggestions on how I might go about testing it? I do have a melting poit apperatus however my batteries are burnt out in my temp. probe and I don't have the cash right now to replace them, so thats out.

Lastly and completely unrelated to this post, could someone point me in the direction of the quick questions thread, I looked but didn't find; even just the catagory that it's in would be great.

thanks in advance for any aid offered.

madscientist - 4-2-2011 at 18:14

NaBH<sub>4</sub> doesn't decompose too quickly in neutral aqueous solution. It does in dilute acid. Try dropping it in some 1M HCl.

Here's your thread: https://www.sciencemadness.org/whisper/viewthread.php?tid=14...

[Edited on 5-2-2011 by madscientist]

garage chemist - 5-2-2011 at 02:32

This behavior is typical of NaBH4, it dissolves in water but the hydrogen release in neutral or alkaline solution is extremely slow.
Add the NaBH4 to an aqueous acid to see its true power.

How has the NaBH4 been stored? It is quite hygroscopic and, despite the slow reaction with water, will over time completely hydrolyze to borate with atmospheric moisture if the container is not airtight.

Satan - 5-2-2011 at 09:21

NaBH<sub>4</sub> is flammable, put some on metal and use cigarette lighter. If bigger amount is set on fire, it will melt and make pop sound.

vulture - 5-2-2011 at 09:54

NaBH4 is quite a tame beast compared to LiAlH4, it can be used in ethanolic solution for example.

SHADYCHASE54 - 5-2-2011 at 10:44

Hello all,
thank you for the tips particularily madscientist, garage chemist and satan, I did end up adding it to an acidic medium and wow! it was a cool vigorous reaction. Regarding storage I had the NaBH sent over sea it was taken out of its container and immediately vacuum sealed in hdpe plastic thrice fold. When I got it I immediately poured it into an oven dryed glass container teflon tape on the threading and taped around the lid. I must feel I am feeling much more confidient that the borohydride is legit. Thanks again.

SHADYCHASE54 - 5-2-2011 at 10:46

Oh yha thanks to madscientist for the link to the short questions thread I am adding it to favorites.

mr.crow - 5-2-2011 at 12:48

Is there a method for titrating NaBH4 to determine its purity?

madscientist - 5-2-2011 at 13:05

Perhaps by addition of KMnO<sub>4</sub> to a cold, strongly alkaline solution of NaBH<sub>4</sub>? I don't know whether NaBH<sub>4</sub> reduces precipitated MnO<sub>2</sub>. If it does, it could get messy.

mr.crow - 5-2-2011 at 13:42

I just remembered I already asked that question a long time ago, whoops

What is the proper storage of NaBH4? I have seen it many times in glass bottles, yet one of the MSDS sheets says to not use glass. Presumably hydrogen builds up inside.