480 g of FeS2 is combined with 12.000mol of molecular oxygen. balanced chemical reaction is

4FeS2 + 11O2 ---> 2Fe2O3 + 8SO2
a. Which cheical will run out first?
b. What mass of Fe2O3is produced?

480g FeS2 = 4 moles

Since 4 moles of FeS2 react with 11 moles of O2, there will be 1 mole of O2 left over.

2 moles of Fe2O3 will result, or 320g