I'm interested in making CaBr2 using NaBr. This is the current idea I've come up with:

 

2 NaBr(aq) + H2SO4(aq) ---> 2 HBr(aq) + Na2SO4(aq)

 

From here, I would cool the solution in an ice bath to precipitate the Na2SO4 (wikipedia says 4.76g of Na2SO4 dissolves in 100ml), and remove the precipitate. So that would mean in a 1L solution, 47.6g would be dissolved, which is 0.3351 moles of Na2SO4 dissolved. From here, mainly HBr would remain in the solution.

 

Next, I'd add Ca(OH)2:

 

2 HBr(aq) + Ca(OH)2 ---> CaBr2(aq).

 

Does this method seem sound? Also, any other suggestions would be greatly appreciated.

Well, seems okay to me as long as you're sure the first equation works, but who knows, I've said some pretty stupid things lately, so don't quote me on it....

 

Just a question, what did you want it for, fire retardant?

I got the reaction from http://www.chemthes.com/rxn.php?entity=14&page=4&type=&side=RHS . Upon further reading of the reaction (click "Reaction Data Page"), it says that this is carried out by conc. H2SO4, but then it also says that the H2SO4 oxidises the Br- to Br2. So, I assume if I use dilute H2SO4 and specific stoichiometric quantities according to the equation, it should work out. If not, I assume using NaHSO4 to produce HBr will work just as well as when it is carried out to procude HCl (by using NaCl, instead of NaBr).

 

I would likw to produce CaBr2, becausw it can be dissolved in acetone, and thus hopefully electrolyzed to give Ca(s).

Edited August 18, 200817 yr by battousai
Forgot to answer why.