[kevinkevin]

I am a bit confused about the reaction that will occur between carbonic acid and calcium carbonate.  When I try to relate the reaction to an apparently similar acid base reaction I get a result that makes it appear as if no reaction would occur.

  CaCO3 + H2SO4--> CaSO4 + CO2 + H2O

     Now for the reaction I am interested in,
   
   CaCO3 + H2CO3 ---> CaCO3 + H2O + CO2 

  The problem I am having is that it appears as though calcium carbonate would just appear again on the product side.  The reason I thought of this equation in the first place is because I was thinking about ocean acidifiction and the tole it is taking on corals ( primarily sps corals) which are made up primarily of calcium carbonate.  I assume that carbon dioxide is the main cause of ocean acidification and that a reaction involving carbonic acid is responsible for damaging the calcium carbonate skeletons of corals.  Any quick insight on this reaction would be great.  Thanks.     
 

   

[Hunter2]

No: What happens in in flowstone caves in the mountains. Think also about acidic salts.

[Sophia7X]

CaCO3 + H2O + CO2    Ca(HCO3)2

Since H2O + CO2   H2CO3, that means CaCO3 + H2CO3   Ca(HCO3)2

Ca(HCO3)2 is soluble so basically carbonic acid would be eating away the calcium carbonate skeletons.

[kevinkevin]

  Thank-you. That is exactly what I was looking for.