This online Theoretical Yield Calculator finds the predicted amount of product when the limiting reagent in a chemical reaction is fully utilized.
How to Find Theoretical Yield
The theoretical yield is the amount of product obtained from the complete consumption of the limiting reactant in a chemical reaction. This is the amount of product that can theoretically be obtained as a result of an ideal chemical reaction. In practice, it is usually different from the amount that you actually get from the reaction in the laboratory. The theoretical yield is commonly expressed in grams or moles.
In order to calculate the theoretical yield, you must first find the limiting reactant in a balanced chemical equation. This is based on the molar ratio between the reagents. The limiting reactant is the one that is in short supply, so that the reaction cannot proceed when it is used up.
To find the limiting reactant, it is necessary to find out how many moles of the initial reactants are involved in the reaction. Then the values found must be compared with the stoichiometric coefficients of the chemical reaction in question.
By comparing the proportions of these values it is possible to determine which reagents are in excess and which reagent is in deficit. The reagent in short supply will be the limiting reactant. Its amount determines the amount of reaction products, or the theoretical yield.
Example of a Chemical Reaction
Consider reaction of 10.5 g of calcium carbonate with 13.6 g of hydrochloric acid. What is the theoretical yield of calcium chloride resulting from this chemical reaction?
First write the following balanced chemical equation:
Molecular weights of CaCO3 and HCl are 100.0869 g/mol and 36.46094 g/mol respectively. So, as we can see, the reaction involves 10.5 / 100.0869 = 0.104909 mol of calcium carbonate and 13.6 / 36.46094 = 0.373002 mol of hydrochloric acid.
That is, for 1 mole of CaCO3 there are 0.373002 / 0.104909 = 3.56 moles of HCl. On the other hand, from the reaction equation, we see that for 1 molecule of CaCO3 there are 2 molecules of HCl. In other words, we have an excessive number of hydrochloric acid molecules and, accordingly, the limiting reagent will be calcium carbonate.
It is the amount of CaCO3 that determines the amount of reaction products. Since the stoichiometry of the reaction shows that there are 1 molecule of each of the reaction products per 1 molecule of CaCO3, then 0.104909 moles of calcium carbonate give 0.104909 moles of each of the reaction products.
In this case, the theoretical yield of calcium chloride will be 0.104909 mol or 11.64322 g, given that the molecular weight of CaCl2 is 110.984 g/mol.
It is worth noting here that the above problem can be easily solved with our Chemical Reaction Calculator. From balancing the chemical reaction equation to calculating the amount of all the reaction products and determining the limiting reactant and the amount of unreacted reagents, all this can be calculated in a fraction of a second.
However, when the stoichiometric coefficients, the molecular weights of the substances involved in the reaction, and the limiting reagent are known, it is easier to use this Theoretical Yield Calculator.
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