Michael and Doreen are correct, calcium carbonate is considered insoluble in water, which is another way of saying that very, very little amounts will actually dissolve.
You can use calcium carbonate's solubility product constant, #k_(sp)#, which is listed as being equal to #2.8 * 10^(-9)#, to determine how much calcium carbonate would dissolve in a liter of water.
The very small amount of calcium carbonate that does dissolve will dissociate into #Ca^(2+)# and #CO_3^(2-)# ions
The #1:1#mole ratio between the ions will ensure that the two concentrations are equal, which implies
#K_(sp) = 2.8 * 10^(-9) = x * x = x^2 => x = 5.3 * 10^(-5)#
This is calcium carbonate's molar solubility in water at a temperature of #25^@"C"#. To determine the mass that contains this many moles, use the compound's molar mass