Sciencemadness Discussion Board

SO2 From CuSO4?

K12Chemistry - 18-4-2013 at 09:48

Does anyone know how i can extract sulfur dioxide from copper sulfate? I am trying to make sulfuric acid without using the electrochemical process. Just so you know the electrochemical process works fine and I can make acid from it it's just I want to try a different method.

Fantasma4500 - 18-4-2013 at 11:10

i believe that CuSO4*5H2O just past 100*C goes into CuSO4 (anhydrous)
after this IIRC theres about 8-900*C to the decomposition of CuSO4
and i believe you get SO3 and CuO at this point..

CuSO4 > CuO + SO3

i think your best bet is using MnO2 and NaHSO4 (im quite sure this will react)
if not then NaHSO3 (you need SO2 to make this tho) + MnO2

if NaHSO4 does work then mix 1:1 molar ratio NaOH H2SO4 (:

i mixed up +40g NaHSO3 and NaHSO4 to mix with MnO2 to make MnSO4 and then later MnCO3
before i knew it i had an very aggresive amount of SO2..
this is where i state that ammonia is fantastic

if just NaHSO4 works it will be somewhat easy to generate pretty pure SO2

edit: forgot to read the use for this
seems it wont be a good way to use NaHSO4 after all

[Edited on 18-4-2013 by Antiswat]

Eddygp - 28-4-2013 at 11:03

I'm not sure... instead of getting CuO and SO3 you might get the next reaction. SO3 isn't as stable as SO2, although I reckon that your reaction might be possible. Just thinking aloud:
2CuSO4 = 2CuO +2SO2 +O2

elementcollector1 - 28-4-2013 at 13:00

Apparently, hot concentrated H2SO4 and Cu (sort of related) can release SO2.

[Edited on 28-4-2013 by elementcollector1]

Fantasma4500 - 28-4-2013 at 13:11

Quote: Originally posted by elementcollector1  
Apparently, hot concentrated H2SO4 and Cu (sort of related) can release SO2.

[Edited on 28-4-2013 by elementcollector1]


i guess you found out this by yourself? (:

conc. H2SO4 produces SO3 when its around 300*C so you should definately be able to tell difference on if the reaction produces SO2 or if the H2SO4 was decomposing..
i guess you know the difference, very interesting..

elementcollector1 - 28-4-2013 at 19:42

Actually, no, from Wiki if I recall.

K12Chemistry - 6-5-2013 at 05:37

Actually I'm trying to make sulfuric acid. So I can't use sulfuric acid to make sulfuric acid :D.

KonkreteRocketry - 6-5-2013 at 07:34

Has any one tried handling liquid SO3 ?

weiming1998 - 6-5-2013 at 08:13

Quote: Originally posted by KonkreteRocketry  
Has any one tried handling liquid SO3 ?


Pure liquid SO3 is not exactly the most desired form of SO3 if you want to store it, due to its reactivity and its ability to polymerize to a solid form. Thus, it is usually handled as a solution of it in concentrated H2SO4, which is much more common and can even be bought commercially.

Making sulfuric acid out of SO3 is certainly a no-go if you don't have any sulfuric acid to start with. Directly adding pure SO3 to water will result in a very violent reaction that produces corrosive, difficult to condense fumes of sulfuric acid.

[Edited on 6-5-2013 by weiming1998]

Eddygp - 6-5-2013 at 13:07

Making sulfuric acid with SO3 might be very difficult in a home lab. I think you'd be better off buying it, despite being complicated sometimes too.

blogfast25 - 6-5-2013 at 13:31

Any starting point should use the sticky thread as a point of reference.