To calculate the molar mass of calcium carbonate CaCO3 , we need to add the molar masses of each element present in the compound.Calcium Ca : 1 atom 40.08 g/mol = 40.08 g/molCarbon C : 1 atom 12.01 g/mol = 12.01 g/molOxygen O : 3 atoms 16.00 g/mol = 48.00 g/molNow, add the molar masses of each element:40.08 g/mol Ca + 12.01 g/mol C + 48.00 g/mol O = 100.09 g/molThe molar mass of calcium carbonate CaCO3 is approximately 100.09 g/mol.