guy - 14-5-2006 at 09:13
How come it is not possible for carbon sulfate to exist. Could it theoretically exist right? by reacting carbon dioxide with concentrated carbon
dioxde. It is similar to reacting ethene with sulfuric acid to form ethyl hydrogen sulfate. The H+ attacks the double bonds. I'm just curious why
it doesn't exist.
12AX7 - 14-5-2006 at 19:23
Not a strong enough acid, AFAIK... carbon doesn't much ionize except when binding energy says so (e.g., carbides, many of which have insane melting
points). Carbon prefers hydrogen, so carbides hydrolyse easily (-C2- is a weak acid and hydrolyzed by H2O, producing C2H2 (acetylene) gas).
I seem to remember something about a CH5+ ion, to do with superacids (fluorosulfonic acid, et al).
Tim
guy - 14-5-2006 at 19:48
Hmm...
Is it possible to form a sulfuric acid analogy of carbonic acid and carbamic acid? And if so what would it be called?
12AX7 - 14-5-2006 at 21:11
Er, sulfamic acid? You can buy that in stores IIRC.
A quick check shows carbamic acid doesn't exist (though the group it represents, amine plus ester, does).
Tim
guy - 14-5-2006 at 21:34
No not sulfamic acid. I mean like H2O + CO2 --> H2CO3, so could there be H2SO4 + CO2 ----> HCO3SO3H
12AX7 - 14-5-2006 at 23:09
Er, carbosulfonic acid then? That's not analogous to slapping an amine on it.
What you describe is the hydration, CO2 is the acid anhydride of carbonic acid.
As for carbosulfonic, I would suppose if it can form (probably not), it would form like an organic carbonate link, i.e., from phosgene, or in a
similar process. That would be HO-CO-O-SO2-OH, where "HO-CO-O" is the HCO3- molecule (bicarbonate), and "O-SO2-OH" is the HSO4- (bisulfate) molecule.
The groups share a common oxygen atom as this is an acid anhydride, analogous to H2S2O7, oleum, which is the half anhydride between two sulfate
molecules. Adding an H2O to that oxygen cleaves the thing yielding H2CO3 + H2SO4. Of course the sulfuric acid would dehydrate the H2CO3 to H2O in
solution, while the CO2 part wouldn't much like to stick around at atmospheric pressure anyway. Good reason to figure this thing will never exist.
Tim