Skill 8.7 Solving problems involving limiting reagents and percent yield

Skill 8.7 Solving problems involving limiting reagents and percent yield 

The limiting reagent of a reaction is the reactant that runs out first. This reactant determines the amount of product formed, and any other reactants remain unconverted to product and are called excess reagents. 

The limiting reagent may be determined by dividing the number of moles of each reactant by its stoichiometric coefficient. This determines the moles of reaction if each reactant were limiting. The lowest result will indicate the actual limiting reagent. Remember to use moles and not grams for these calculations. 

Example Consider the reaction BH + N 2NH3 and suppose that 3 mol H2 

Solution The equation tells us that 3 mol H2 will react with one mol N2 to 

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