Sciencemadness Discussion Board

Reversing sulfate salts reaction

helzblack - 30-8-2024 at 18:55

I have seen how it is possible to turn salt and boric acid back into HCL with enough heat(reversing the reaction). It does make me wonder, why is this not done for sulfate salts(no cheating with bisulfates or pyrosulfate) to make sulfuric acid?

In other words are there sulfate salts that can be turned back into sulfuric acid with enough heat?

clearly_not_atara - 30-8-2024 at 19:39

Sulfuric acid decomposes before it boils at atmospheric pressure. So this route is not possible.

helzblack - 30-8-2024 at 23:49

wait so you need to compress(or lower pressure) it? would you need a teflon lined container?

helzblack - 30-8-2024 at 23:50

are there catalysts that help?

RU_KLO - 31-8-2024 at 03:09

If You want to transform a sulfate salt into sulfuric acid heat it till decompostion and libérate SO3. Bubble SO3 into water. This was the method used back in time for producing H2SO4 with iron sulfate.

https://www.mcgill.ca/oss/article/quirky-science-science-sci...

Or use oxalic acid to iron sulfate to make iron oxalate + sulfuric acid. Check post from keras or nurd rage video. Use the search engine

[Edited on 31-8-2024 by RU_KLO]

bnull - 31-8-2024 at 08:57

Quote: Originally posted by RU_KLO  
Bubble SO3 into water.

Better not. The mist, remember. The best way is to bubble it into concentrated sulfuric acid but, alas, sulfuric acid is exactly what we want and do not have.

There is a lot of usable information in this thread: Small scale production of H2SO4 in the amateur lab.