The Percentage Yield

Understanding Percentage Yield

Percentage yield is a concept in chemistry that quantifies the efficiency of a chemical reaction.
It compares the actual yield of an experiment or process with the maximum possible yield, assuming the reaction goes to completion.

Importance of Percentage Yield in Industry

In industrial processes and research, achieving a high percentage yield is desirable as it indicates efficient use of resources.
A lower percentage yield signifies side reactions, waste products, or that the reaction didn’t go to completion.

Calculating Percentage Yield

The formula for calculating percentage yield is: (actual yield / theoretical yield) x 100%.
Note that both actual yield and theoretical yield must be in the same units. Usually, these values are given in grams (g).

Factors Affecting Percentage Yield

The efficiency of reactant conversion can affect the percentage yield. Not all reactants are converted into products due to side reactions or unreacted reactants.
Recrystallization or purification of the product can also decrease the final yield.
Practical issues such as transfer of materials, filtration, or evaporation can lead to losses and lower the yield.

Example of Calculating Percentage Yield

If the theoretical yield of a reaction is 10.0g but the actual yield obtained in the experiment is 8.5g, the percentage yield is: (8.5 / 10.0) x 100% = 85%.

Remember, percentage yield is a measure of the efficiency of a chemical process, with 100% yield showing the maximum efficiency. However, achieving 100% yield is nearly impossible due to losses and side reactions. In exams, questions on percentage yield may involve calculations using the formula: (actual yield / theoretical yield) x 100% or understanding factors impacting the efficiency of chemical reactions.