.4941g of an iron-containing compound yielded .1116g of Fe2O3 upon oxidation. What is the mass percent of iron in the compound?
%Fe = (g Fe in sample/mass sample)*100.
You know mass sample. Calculate g Fe.
0.1116 g Fe2O3 x (2 moles Fe/1 mole Fe2O3) = 0.1116 x (2*55.85/molar mass Fe2O3) = xx g Fe.
Substitute into the first equation and obtain %Fe.
