What is the mass in grams of aluminum metal (26.98 g/mol) that reacts to form 2.80 g of iron (55.85 g/mol)?
3 FeO (l) + 2 Al (l) → 3 Fe (l) + 1 Al2O3

Starting with 0.450 g of potassium chlorate (molar mass 122.55 g/mol), a student determined that the reaction released 0.156 g of oxygen gas. Calculate the percent yield for O2.
2 KCIO3 (s) → 2KCl (s) + 3 O2