When a 13.60-g sample of a compound containing only magnesium and oxygen is decomposed, 5.40 g of oxygen is obtained. What is the percent composition of this compound?
All we have done is to divide the elemental mass by the compound mass, and made it into a percentage.
We could also use these percentages to give an empirical formula. We assume that there are
And thus there are
We divide thru by the lowest molar quantity to give an empirical formula of