Calculating Yields

Theoretical Yield

Definition

The maximum amount of a product formed (assuming the limiting reagent has reacted). Obtained through Stoichiometry.

Actual Yield

Definition

The amount of a product actually obtained from a chemical reaction. Obtained either through experiment, or given in the question.

Formula

Example

7.00g of are added to a solution with the excess dissolved . 7.32g of are obtained. Calculate the % yield of the .

solution
Create a formula with double displacement reaction

Calculate the theoretical yield:

Calculate the percentage yield:

Example

Consider the following unbalanced chemical reaction:

When an quantity of is reacted with of , a quantity of is formed. What is the percentage yield?

solution
Balanced equation:

Since , is the limiting reagent.

Atom Economy

Formula

Calculated assuming a yield of 100%

Example

The conversion of biomass into biofuels is an important process for sustainable energy production. Consider the following reaction mechanism for the conversion of cellulose (polymer of ) into ethanol (), a biofuel:

Step 1: Hydrolysis of cellulose to glucose:

Step 2: Fermentation of glucose to ethanol

Calculate the atom economy for this reaction mechanism.

solution