Re: pH required to decompose calcite?

Repeating Rifle wrote:
>
> Although I know more chemistry than the typical bloke on the street or
> college graduate, I am not a professional chemist.
>
> How would I go about calculating the pH at which calcium carbonate
> (limestone, calcite, marble) decomposes to give carbon dioxide? Getting a
> source of such information is good enough.
>
> What chemical equations do I have to consider?
> What equilibrium constants do I need to know?
> Is there anything else?

pKa for HCO3(-) being protonated and the kinetics of dehydration
thereafter. The latter reaction is notoriously sluggish (seltzer)
(hence carbonic anhydrase in biological systems) and requires buble
nucleation for facile gas evolution even at supersaturation.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
.