To Find the Limiting Reagent You Follow a Simple Equation

coefficient of the molar mass x molar mass of reagent 2 
coefficient of the molar mass x molar mass of reagent 1     X    the amount of reagent 1 given   =   the amount of reagent 2 needed

The chemical equation will give you two amounts. If the amount you get as the answer of the equation is more then the amount given, then reagent 2 is the limiting reagent. If it is less than the given amount, then reagent 1 is the limiting reagent.