Calculate the empirical formula of tricalcium aluminate?

Question

Tricalcium aluminate, an important component of Portland cement, is 44.4% calcium and 20.0% aluminum by mass. The remainder is oxygen.

Answer 1

Divide each component% by its molecular mass.

Ca = 40
Al = 27
O = 16

That will give you the ratio of the empirical formula. Since you need whole numbers, divide each ration by the smallest one until you get whole numbers. Then you are done