Interaction of calcium carbonate with hydrochloric acid.

The reaction of calcium carbonate with hydrochloric acid will look like this:

CaCO3 + 2HCl —-> CaCl2 + CO2 + H2O.

Here CaCO3 is solid and HCl is aqueous. Among the products, CaCl2 is solid, CO2 is gas and H2O is liquid. 1 mole of CaCO3 will react with 2 moles of HCl. If the reaction is closed, there will be CO2 in the system, then a reversible reaction is likely to occur. On the other hand, if the reaction is carried out in an open system, CO2 will be outside the system. As a result, there will be no reversible reaction.