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Hello there community, I'm still a high school student, but I'm much into math, chemistry and physics, so I was wondering if someone could "illuminate" me in a problem.

I'm needing H2SO4 (sulfuric acid) but it doesnt seems so easy to get, so I got the wonderful idea of producing it.

I know that to make that oxoacid i would need H2O + SO3; my question is, how to make SO3?

I suppose that if I burn sulfur (easy to get at the drugstore) it would end being something like these:

S + O2 ---> SO2

But that still isn't what I need, someone knows if I can use a catalyst to get SO3? and which one?

Any recommendations?


Anyway, thanks for your time :D

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That stuff's nasty, you really don't want to try that. Besides, you'd need to add the SO3 to sulphuric acid (it will explode if you put it in water). Also, to convert SO2 to SO3 you'd need a really hot catalyst (usually V2O5). Your best bet if you really want to synthesize it is to mix SO2 and pretty concentrated H2O2 (hydrogen peroxide)

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If you need dilute sulfuric acid, consider looking for replacement battery electrolyte at car supply places. It's supposedly quite clean.


The drain cleaners, while concentrated often have a plethora of tarry brown material, iron contamination, foaming agents, or buffers added limiting their usefulness.


I take the following excerpt outlining the hazards of the peroxide route from user Formatic on sciencemadness.org. I strongly advise against it on the basis of his experiences.


"A way to H2SO4 is from estimated amounts of H2O2 and SO2. H2O2 will oxidize SO2 even in the cold to form H2SO4. Sources of SO2 is by burning and roasting sulfides (pyrite (FeS2); sphalerite and ZnS; chalcopyrite (CuFeS2), galena (PbS), etc), sulfur, or decomposing sulfites, or thiosulfites with a dilute acid...


I’ve decided to try the above oxidation, but aborted the procedure because the reaction got too violent. I added 110 g of a mixture of sodium hyposulfite and metabisulfite to a 500 mL flask, the flask had a rubber stopper with a 50 mL separatory funnel and also a tube running out of it. The tube lead into 50 mL of 35% H2O2 in a 100 mL graduated cylinder. Then the separatory funnel filled with 16.8% pure HCl. The acid was then let drip in slowly and portionwise with occasional stirring.


At first the bubbling of SO2 proceeded smoothly for several minutes, and the reaction between H2O2 and SO2 is highly exothermic reaching around 105ºC at some points. Though after some volume reduction, at some point the SO2 generator did something unexpected, without any warning whatsoever e.g. effervescence, foaming, etc. as SO2 was bubbling into the H2O2, the stopper blew off violently from the flask and the tubing shot out of the graduated cylinder, the acid/peroxide mixture spattered all over even on my arms and over the gas mask. After washing off, I came back and tried an even slower addition, but even then the exact same thing happened. I thought maybe the acid was too strong and diluted it with around 2 times the volume with water. The same thing happened! So I halted the procedure."

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