Theoretical yield formula

The quantity of a product obtained from a reaction is expressed in terms of the yield of the reaction. The amount of product predicted by stoichiometry is called the theoretical yield, whereas the amount obtained actually is called the actual yield. A reaction yield is reported as the percentage of the theoretical amount.

The formula for percentage yield is given by

Percentage yield= (Actual yield/theoretical yield )x100

Rearrange the above formula to obtain theoretical yield formula

Example 1

Determine the theoretical yield of the formation of geranyl formate from 375 g of geraniol. A chemist making geranyl formate uses 375 g of starting material and collects 417g of purified product. Percentage yield is given as 94.1%

Solution

The actual yield is 417 g which is the quantity of the desired product.

Percentage yield is 94.1%

Therefore,

Theoretical yield=(Actual yield/percentage yield) x 100

= (417 / 94.1)100

= 443g