How do we determine our limiting reactant?
Flexi Says: In the real world, amounts of reactants and products are typically measured by mass or by volume. It is first necessary to convert the given quantities of each reactant to moles in order to identify the limiting reactant. Use the atomic masses of the elements in the reaction to determine the number of moles of each present. Then, use the balanced equation to calculate the number of moles of each element that would be needed for the reaction. Compare this result to the actual number of moles present in the given mass or volume of reactants.
The Determining the Limiting Reactant lesson contains more information and sample problems.