Question

What percent of calcium carbonate is oxygen?

Answer 1

Oxygen makes up `48%` of the mass of `CaCO_3`

Explanation:

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 `CaCO_3`

Now. to find percent composition, you take each element separately, and do this calculation:

`("mass of element" )/("molar mass of compound") xx 100`

So, for oxygen, this would be

`(48.0)/(100.1) xx100=48.0%`