iron(III) oxide reacts with carbon monoxide gas to form solid iron metal and carbon dioxide gas:

Question

Fe2O3 + 3 CO --> 2 Fe + 3 CO2

If you begin the reaction with 84.34 g of iron(III) oxide and 68.87 g of CO, which reactant will be in excess at the end of the reaction and how many grams will be remaining?

Answer 1

I work limiting reagent problems by solving TWO simple stoichiometry problems. Here is a solved example of a simple stoichiometry problem.
http://www.jiskha.com/science/chemistry/stoichiometry.html
Using the amount of Fe203 in the problem, solve for the amount of Fe that will be formed. Then use the amount of CO in the problem and solve for the amount of Fe. The SMALLER amount of Fe will be the correct amount and the reactant producing that value will be the limiting reagent. After identifying the limiting reagent, use that value to determine the amount of the non-limiting reagent will be used and subtract from the original amount to fine the grams left unreacted.