What is the empirical formula of an unknown compound that contains 60.3% of magnesium and 39.7% of oxygen?

1 Answer
Apr 26, 2016

MgO, magnesium oxide.

Explanation:

For empirical formula problems we assume 100 g of compound, and then divide thru by the ATOMIC weights of each constituent.

There are thus 60.3g24.305gmol1 = 2.48molMg, and

39.7g15.999gmol1 = 2.48molO.

There is clearly a 1:1 molar equivalence, and the empirical formula is MgO, as we would anticipate.