How many grams of SO3 are produced when 20 g FeS2 reacts with 16g O2 according to the balanced equation?

Question

4FeS2(s)+15 O2(g)>>>2Fe2O3+8SO3(g)

Answer 1

Here is a worked example of a stoichiometry problem. Just follow the steps.
http://www.jiskha.com/science/chemistry/stoichiometry.html