Theoretical Yield Calculator

The theoretical yield calculator for chemical reactions that calculate theoretical yield of a chemical reactions.

What is Theoretical Yield?

In chemistry, theoretical yield is said to be the quantity of product, which obtained from the complete conversion of the limiting reactant in a chemical reaction. It is said to be the amount of product resulting from a perfect (theoretical) chemical reaction, and that’s why not as same as you will actually get from a reaction in the lab.

However, theoretical yield can obtained under the perfect conditions, these conditions indicates where no product is lost in the process, means:

• no impurities mixed in the reactants
• no production of unexpected byproducts that can reduce the yield
• no loss of product because of any measurement, processing, and handling of reactants or products

What is Theoretical Yield Formula?

The theoretical yield equation used in finding theoretical yield from the mole of the limiting reagent, assuming 100 percent efficiency. So, no need to worry more about how to find theoretical yield, the given theoretical yield formula does work best for you!

Where;

• moles of limiting reagent in reaction = mass of limiting reagent/ (molecular weight of limiting reagent * stoichiometry of limiting reagent)
• Stoichiometry is said to be as the number before the chemical formula in a balanced reaction. If no number is found, then the stoichiometry is said to be 1. Keep in mind, the stoichiometry is the thing that needed to reflect the ratios of molecules that comes together to form a product. However, the above yield calculator can be used any way you like, it not only helps to perform theoretical yield calculation but also calculate limiting reagent (moles), and stoichiometry of product.

How This Calculator Works:

You just have to stick to the following steps to calculate theoretical yield, read on!

Inputs:

About Limiting reagent:

• At first, you have to enter the mass of limiting reagent into the designated field of the above calculator, it can either be in µg, mg, g, kg, lbs.
• Very next, you have to enter the molecular weight of limiting reagent into the designated field
• Now, you have to enter the stoichiometry of limiting reagent into the designated box

About Desired Product:

• Here, you have to enter the number of moles that you found from the balanced equation into the designated field
• Very next, you have to enter the molecular weight of the desired product into the designated

Result:

Once you added all the above values, simply hit the calculate button, this smart calculator for theoretical yield shows:

• Theoretical Yield
• Limiting Reagents (moles)
• Stoichiometry of Product

How to Calculate Theoretical Yield?

Finding theoretical yield becomes easy by identifying the limiting reactant of a balanced chemical reaction. In order to calculate it, the first step is to balance the equation, if it’s unbalanced.

In very next step, you have to identify the limiting reactant (this all based on the mole ratio between the reactants. Remember that the limiting reactant is not found in excess, so the reaction cannot proceed, if once it is used up!

So, to find the limiting reactant, you need to:

• If the quantity of reactants is given in moles, then you have to convert the values into grams
• Very next, you have to divide the mass of the reactant in grams by its molecular weight in grams per mole
• Alternatively, for a liquid solution, you ought to multiply the amount of reactant solution in milliliters by its density in grams per milliliter. Then, you have to divide the resulting value by the reactant’s molar mass
• Now, you ought to multiply the mass obtained using either method by the number of moles of reactant in the balanced equation
• Now you come to know the moles of each reactant. You ought to compare this to the molar ratio of the reactants to decide which is available in excess and will here used up first (the limiting reagent)
• Once you determined the limiting reactant, you ought to multiply the moles of limiting reaction times the ratio between moles of limiting reactant & product from the balanced equation. By this, you will get the number of moles of each product.

To get the grams of product, you have to multiply the moles of each product by its molecular weight.

Theoretical Yield Example:

How to calculate theoretical yield of aspirin, an experiment in which you prepare acetylsalicylic acid (aspirin) from salicylic acid, and you know from the balanced equation for aspirin synthesis in which the mole ratio between the limiting reactant (salicylic acid) and the product (acetylsalicylic acid) is 1:1.

If you have 0.00153 moles of salicylic acid, then the theoretical yield is:

Theoretical yield = 0.00153 mol salicylic acid * (1 mol acetylsalicylic acid / 1 mol salicylic acid) * (180.2 g acetylsalicylic acid / 1 mole acetylsalicylic acid)

Theoretical Yield = 0.276 grams acetylsalicylic acid (aspirin)

References:

From a chem.libretexts – All about chemistry – Excess reagent, limiting reagent – Theoretical Yield – calculate theoretical yield

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