1. The problem statement, all variables and given/known data What would be the mass of oxygen in 2.5 x 102g of CaCO3? Given: mCaCO3=250g M=100.09g/mol n=2.498mol 2. Relevant equations ? 3. The attempt at a solution mass of O=250g/3 atoms of O mass of O=83g Is that correct? Bc if it is can someone please explain why it's correct.