A limiting reactant is a reactant that limits how much product will be produced. It will run out first and stop the reaction from going any further.
In order to do limiting reactant calculations, we MUST first have a BALANCED equation. Please make sure the equation is balanced before going further when you do a problem.
1. How To Find Liming Reactant When Moles Are Given:
Calculate moles of product from each reactant using the coefficients in the balanced equation. The reactant that gives the LEAST moles of product is limiting. If there are two products, choose either one but make sure to use the same product for both reactants.
Reactant A is limiting because it produced the least moles of product C.
2. How To Find Liming Reactant When Grams Are Given
When grams of each reactant are given, first convert them to moles by using molar mass. Then, convert moles of each reactant to moles of the product by using coefficients in the equation. The reactant that produces the least product is the limiting reactant.
Zinc is limiting because it produced the least moles of product.
3. How To Find Theoretical Yield
Theoretical yield is the maximum amount of product that can be obtained in the reaction. To find theoretical yield, we simply need to convert moles of the product that the limiting reactant produces to grams using molar mass of the product.
4. How To Find Percent Yield
% yield tells us what is the % of the product that was obtained in the lab out of the maximum amount that could be produced.