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Author: Subject: Sulphur Trioxide and Oleum Using a Box Oven - Illustarted Practical Guide
PHILOU Zrealone
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[*] posted on 7-8-2015 at 01:57

NH4 persulfate may burn or explode because of the peroxydic link (molecule contains oxydiser and reducer).

Also to take into account:
NH3 + SO3 --> NH2-SO3H
and maybe
2 NH3 + SO3 --> NH2-SO2-NH2 + H2O (sulfamide)
and related polymers (imidodisulfamide, trisulfimide... and from memory a hexamethylene tetramine related compound with strong curarisant (curare like) effect).

[Edited on 7-8-2015 by PHILOU Zrealone]

PH Z (PHILOU Zrealone)

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[*] posted on 8-8-2015 at 21:42

Thanks for the article,
I wanted to try this one, haven't got around to it, don't like the exposure, and I only wanted it to remove the 2% of water in my concentrated h2so4 to increase yields in one of my experiments.

In the "The SO3 / H2O system" part of the article it states:

"If one tries distilling sulphuric acid with b >> a, initially a dilute acid distils, with the fraction of the SO3 progressively increasing until the maximum boiling point at 337C of the liquid/vapour azeotrope of 98%/2% H2SO4/H2O is reached. After this no further concentration in the SO3 component can be obtained. Hence distilation can not be used to prepare oleum/SO3."

Then in the "The SO3 / H2O / Na2SO4 system" part of the article, it states:

"We can say that the addition of Na2SO4 to H2SO4 breaks the azeotrope."

1) So if I wanted just 100% h2so4, I could slowly heat up sodium bisulfate up to 780 degrees without a cut, while condensing and collecting the runoff.


2) could I take a liter of h2so4, add x amount of sodium bisulfate, heat until approx. 20ml of h20 comes over, then triturate, and use, or continue heating to remove more water?

I'm not sure how the formula would go, and I'm not sure if this isn't all gibberish, I'm tired, and feel lame, but I still want to get to 100% acid.


[Edited on 9-8-2015 by shadow]
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