How many moles of CaCO3 are present in 30.6g of it ?

2 answers

mols = grams/molar mass.
You have to determine the molar mass of CaCO3, by getting the molar mass of Ca and the molar mass of C, and the molar mass of O multiplied by 3 (since there are 3 oxygen atoms).

You would get 100.087 g/mol.

You would then do the mass/molar mass.

30.6/100.87 = your answer