jamit
Hazard to Others
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Registered: 18-6-2010
Location: Midwest USA
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bumping and hydrobromic acid
I've been reading the board lately on hydrobromic acid and attempting to distill it but I've ran into some problems with bumping.
After's adding sulfuric acid to sodium bromide in 1:1 molar ratio, and putting that in an ice bath to ppt sodium bisulfate as much as possible... I
setup for simple distillation.
The first to come over is mostly water and that there was no problem... the temperature than shot up to around 122-125C. I changed receiving flask to
collect the hydrobromic acid.
After about 30 minutes, the bumping started... I put in boiling stones before the distillation but that was useless as it just floated and would not
submerged. The bumping become too violent so I shut off the heating mantle and waited for it to cool. Afterward, I put 5 pieces of broken stirring
rod and removed any crystallized sodium bisulfate by decanting the solution into another 500ml rbf. Again I setup for simple distillation.
Again everything was fine but after awhile (about 20mins) the bumping began again. What am I doing wrong? How can I stop the bumping?
Any help would be greatly appreciated. thanks.
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AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
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Registered: 2-3-2011
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One does not distill bromides with sulfuric acid, because the HBr tends to get oxidized by the H2SO4.
It is best to use phosphoric acid instead.
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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jamit
Hazard to Others
Posts: 375
Registered: 18-6-2010
Location: Midwest USA
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can you use 40-50% phosphoric acid to do this or does it have to be 85% phosphoric acid?
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