KevinHeard - 7-7-2007 at 11:08
I need help to make CaSO3, without using SO2 gas.
I have tried desolving Ca(OH)2 in a soultion of NaHSO3. Don't seem to have sucess though.
Any help will greatly be appreciated.
CaSO3 madness
KevinHeard - 7-7-2007 at 12:26
Have found a possible solution.
I am lead to believe that reacting sulphurous acid (H2SO3) with calcium carbonate (CaCO3) will do the trick.
H2SO3 + CaCO3 = CaSO3 + H2O + CO2
CaSO3 madness
KevinHeard - 7-7-2007 at 12:31
This poses a new problem - how to make H2SO3 without bubbbling gases and stuff.
Have found a web site:
www.mspong.org/cyclopedia/chemical.html
They claim that under a gentle heat H2SO4 + S = H2SO3
This does not make sense!!!
garage chemist - 7-7-2007 at 12:40
That last equation does not work as described, dont try it.
H2SO4 + S would make H2SO3, but only as SO2 gas that escapes. Also, a lot of heat would be needed.
There is no good way to make CaSO3 without "bubbling gases".
React your NaHSO3 with acid and bubble the SO2 into Ca(OH)2 suspension, that will work. Or heat H2SO4 with S to make the SO2 gas.
not_important - 7-7-2007 at 15:58
You possibly might be able to make CaSO3 by reaction CaCl2 and NaHSO3 in concentrated solution, as CaSO3 has a low solubility and might precipitate
out. As that reaction will release SO2, a suspension of almost an equal molar amount of Ca(OH)2 in the CaCl2 could be used, but you do want just a
little excess SO2. Too much excess SO2 will result in the CaSO3 dissolving as the bisulfite, but a trace helps.
2 NaHSO3 + CaCl2 => CaSO3 + 2 NaCl + "H2SO3'"
"H2SO3" + Ca(OH)2 => CaSO3 + 2 H2O
Reacting in a closed container, but one that will pressure release and/or be safe if it cuts loose, could be useful. A soft drink bottle that you
"burp" as an example.
Cool, filter quickly, wash with a little ice water, then alcohol to remove water. Protect from air, as that oxidises it to the sulfate.
CaSO3 madness
KevinHeard - 8-7-2007 at 12:52
Thanks for the help. Will put it to the test and let you know.
Thanks again.