1. The problem statement, all variables and given/known data 0.3106 g of an iron-containing compound yield 0.07017 g Fe2O3 upon oxidation. What is the mass percent of the iron in the compound?? 2. Relevant equations stoichiometry? 3. The attempt at a solution (0.07017 g Fe203)(1 mole Fe2O3/ 159.7 g Fe2O3)(2 moles Fe/1 mole Fe2O3)(0.3106g Fe)(1 mole Fe) = 2.729468003x10^-4 grams Then I took 2.72x10^-4 grams / 0.07017 compound grams of Fe2O3 = .00388979 x 100 = .3889 percent . What did I do wrong?? Was I off on sig figs?