With mineral acids: exothermic reaction generating combined salts and CO2 gas.
With organic acids: same kind of reactions, easily forming a superficial coating if the acid is used in a small quantity.
Solubility in water
Solubility in water containing no carbon dioxide is very small and increases with temperature.
On the contrary, in water containing CO2 (e.g. once in contact with the air), solubility is noticeably increased and in this instance, decreases with temperature.
In an atmosphere of CO2, solubility increases one hundred-fold and soluble bicarbonate [Ca(HCO3)2] is formed.
In all situations, aragonite is about 10% more soluble than calcite.
