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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: kovsky on February 02, 2010, 04:45:24 PM

Title: Boron tribromide (BBr3) concentration
Post by: kovsky on February 02, 2010, 04:45:24 PM
Hi all,

We have a bottle of old BBr3 solution (1M in hexanes) in our lab and I am constantly using it. Hovewer, I have some doubts that the real concentration is not 1M anymore.

Anyone knows how I could determine the concentration?

Notes:
- 11B NMR of it has only one peak, so, no other boron species in there;
- the color of the solution is dark grey.
- I thought about hydrolyzing it to B(OH)3, but then how to separate boric acid from other possible solids?
Title: Re: Boron tribromide (BBr3) concentration
Post by: gfunk on February 03, 2010, 08:04:52 PM
Precipitate Br with AgNO3 and do a gravimetric analysis?
Title: Re: Boron tribromide (BBr3) concentration
Post by: russellm72 on February 10, 2010, 07:35:08 AM
Sorry that sounds like a mare!

I remember my bottle of BBr3 being orange. Is it not working? Why not just add more if it isnt...

Or just buy a new bottle its not expensive...

R