Cave Formation Equilibria

Caves form when carbon dioxide dissolves in water to produce carbonic acid, which reacts with solid calcium carbonate to produce soluble calcium and hydrogen carbonate ions. This process is actually an equilibrium. When the water containing these dissolved species reaches the open space of the cave, carbon dioxide moves from the solution into the air of the cave. By LeChatelier’s Principle, the equilibrium shifts to replace the lost carbon dioxide, and solid calcium carbonate precipitates to slowly produce amazing features. Special thanks to the folks at Bridal Cave at Lake of the Ozarks, MO, for letting me shoot this video.

The Bradley University Chemistry Club Demo Crew is grateful for support from the Illinois Heartland Section of the American Chemical Society and the Illinois Space Grant Consortium.