symboom
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SO2 Oxidation with Persulfate to Sulfuric Acid
does anyone know if a solution of sodium persulfate will oxidize sulfur dioxide gas? if it is lead into the solution to sulfuric acid.
Na2S2O8 +2H2O + SO2 --> Na2SO4 + H2O2 + SO2 --> 2H2SO4
[Edited on 24-9-2011 by symboom]
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Picric-A
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IF this reaction does work (and thats a big IF), then all you will be left with is a solution of sodium busulphate, which is a readily available and
cheap chemical, often sold as 'dry acid' from pool stores.
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symboom
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it is a powerful oxidizer used to be used to produce hydrogen peroxide and sodium bisulfite when heated decomposes to sulfur dioxide (which could be
refluxed to react with the hydrogen peroxide) and sodium sulfate
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AndersHoveland
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Persulfate is a very powerful oxidizer, especially when heated. There is no doubt that it should be powerful enough to oxidize SO2.
Theoretically, the equation would be:
K2S2O8 + SO2 --> K2S2O7 + SO3
but in practice, such a reacion is not likely to work. Potassium persulfate easily decomposes below its melting point, so it would be difficult to
react solid persulfate with gaseous sulfur dioxide. Not to say that it would be absolutely impossible, however. There may likely be some clever way to
do it, but it would probably not be a practical route.
K2S2O8 could be dissolved in concentrated sulfuric acid, and sulfur dioxide could be bubbled in. At normal temperatures and pressures, in an 80% (by
mole ratio*) concentration of H2SO4, 0.05 moles of SO2 can dissolve per mole of H2SO4.
* which means a solution containing 4 molecules H2SO4 for every 1 molecule of H2O.
The persulfate method could potentially be used to bring concentrated sulfuric acid solutions to higher concentrations.
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symboom
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quote: Potassium persulfate easily decomposes below its melting point, so it would be difficult to react solid persulfate with gaseous sulfur dioxide
i was thinking of the persulfate salt as it forms hydrogen peroxide and is cheaper than 30% hydrogen peroxide
no not molten persulfate i mean aqueous
persulfate in solution and reacting so2 with that solution
[Edited on 25-9-2011 by symboom]
found a form of some one making sulfur trioxide
but im thinking of a different way i have sulfur left over and
some sodium persulfate and i want to turn it all to sulfuric acid
hmm maybe add sulfur to the mix it persulfate generates oxygen
but i need the sulfur i add to turn into sulfur trioxide too and lead it all into water
-------------------------
as he states
When sodium persulfate is heated, it loses oxygen to form sodium pyrosulfate:
2Na2S2O8 --> 2Na2S2O7 + O2
The evolved oxygen contains a small amount of ozone, which is identifiable by its smell.
Sodium pyrosulfate further decomposes into sodium sulfate and sulfur trioxide, but
the reaction only takes place when sulfuric acid is present:
Na2S2O7 + H2SO4 --> Na2SO4 + SO3
The sulfuric acid plays the role of a catalyst, it does not take part in the overall
reaction, but without its presence, no SO3 is formed.
excerpt from
http://www.sciencemadness.org/member_publications/SO3_and_ol...
[Edited on 25-9-2011 by symboom]
[Edited on 25-9-2011 by symboom]
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AndersHoveland
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Trying to decompose pyrosulfate into sulfur trioxide requires strong heat. A typical electric stove top is not quite hot enough.
If you want to react aqueous potassium persulfate with sulfur dioxide, then yes you will get dilute sulfuric acid. The reaction would be:
K2S2O8 + SO2 + (2)H2O --> (2)KSO4H + H2SO4
You will not be able to use persulfate dissolved in water to make sulfur trioxide, because sulfur trioxide violently reacts with water.
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