To calculate the molar mass of Calcium Carbonate CaCO , we need to find the molar mass of each element present in the compound and then add them together.Calcium Ca : 1 atom 40.08 g/mol molar mass of Ca = 40.08 g/molCarbon C : 1 atom 12.01 g/mol molar mass of C = 12.01 g/molOxygen O : 3 atoms 16.00 g/mol molar mass of O = 48.00 g/molNow, add the molar masses of each element together:Molar mass of CaCO = 40.08 g/mol Ca + 12.01 g/mol C + 48.00 g/mol O = 100.09 g/molSo, the molar mass of Calcium Carbonate CaCO is 100.09 g/mol.