[flick-a-bic]

Hey I need to swap anions on my hydroxyl ammonium from chlorine to bromine.

I figure just doing this with a 1:1 stoicheometric amounts of HBr added to the hydroxyl ammonium chloride (dissolved in a little water) will work just fine. Then boil off the water and HCl gas formed.

Is there anything wrong with this procedure? Maybe a better way or should I add excess HBr? How about purifying steps after.

[Dan]

What's the boiling point of HBr?

I would use a large excess.

[flick-a-bic]

I thought about adding excess. Turns out not to matter. I found hydroxyl amine and can just add HBr to that instead for a pure product instead of the shady ion displacement.

Thanks

[Babcock_Hall]

If I were starting with the chloride salt, I would use an ion-exchange resin in the bromide form.  The relative selectivities of various anions is known for many resins, and I would choose how much of an excess to use based upon that.