Justin - 7-6-2010 at 07:42
Hi, i was reading in the member publications that sodium persulfate can be used to produced SO3 in order to make oleum, will potassium persulfate work
inplace of its sodium counterpart?? jw because for me K2S2O8 is much more easy for me to aquire than Na2S2O8. Thanks
quicksilver - 7-6-2010 at 16:24
As strange as it seems Oleum can negatively complicate many nitrations. If the purpose is not a mixed acid nitration, it's can be worth the trouble.
Anders Hoveland - 15-6-2010 at 17:45
An excellent way I have found is to start with sodium bisulfate. Heat to make sodium pyrosulfate. Heat boric acid to make boric oxide. Then heat the
B2O3 and Na2S2O7. Sulfur Trioxide can be distilled out at quite a low temperature, only around 250-350degC. It leaves behind a borosulfate mess. And
the solids have to be put in a little stainless steal dish otherwise it will melt into the glass bottom. Interestingly SO3 reacts with NO2F to make
nitronium fluorosulfate, since SO3 is a strong lewis acid.
[Edited on 16-6-2010 by Anders Hoveland]
Formatik - 18-6-2010 at 01:33
It would be easier instead to heat H2SO4 with pyrosulfate (or persulfate) to get sulfur trioxide, since H2SO4 is easier to obtain and make than B2O3.
I would think the hot SO3 also attacks the stainless steel.
Anders Hoveland - 18-6-2010 at 10:08
Possibly Ag2S2O7 and anyhydrous HCl gas could yield chlorosulfuric acid HSO3Cl, which hydrolyzes to H2SO4.
Also calcium perchlorate and HF gas in HClO4 solvent could make more anyhydrous HClO4.
Or Cu(ClO4)2 and H2S, since CuS is insoluble. HClO4 will not oxidize much at room temperature, dilute HClO4 not even reacting with Zn and HCl
together.
CaS2 can be made by boiling S , Ca(OH)2, in water with a little soap, other byproducts are Ca thiosulfate. Upon adding acid, Calcium polysulfide
liberates H2S.
[Edited on 18-6-2010 by Anders Hoveland]