What percent of calcium carbonate is oxygen?
Oxygen makes up
To calculate percent composition by mass, you start by considering one mole of the given compound. The mass of one mole of calcium carbonate is 100.1 g
Of that mass,
40.1 g is due to the one mole of calcium atoms it contains.
12.0 g is due to the one mole of carbon in it, and
48.0 g is due to the three moles of oxygen atoms in one mole of
Now. to find percent composition, you take each element separately, and do this calculation:
So, for oxygen, this would be