Why yield is not 100

Chemists need a measurement that indicates how successful a reaction has been. This measurement is called the percent yield. To compute the percent yield, it is first necessary to determine how much of the product should be formed based on stoichiometry.

This is called the theoretical yield , the maximum amount of product that could be formed from the given amounts of reactants. The actual yield is the amount of product that is actually formed when the reaction is carried out in the laboratory. The percent yield is the ratio of the actual yield to the theoretical yield, expressed as a percentage:. Percent yield is very important in the manufacture of products. Much time and money is spent improving the percent yield for chemical production.

When complex chemicals are synthesized by many different reactions, one step with a low percent yield can quickly cause a large waste of reactants and unnecessary expense. When a chemist synthesizes a desired chemical, he or she is always careful to purify the products of the reaction. Potassium chlorate decomposes upon slight heating in the presence of a catalyst, according to the reaction below. What is the theoretical yield of oxygen gas? What is the percent yield for the reaction?

First, we will calculate the theoretical yield based on the stoichiometry. Step 1: List the known quantities and plan the problem. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance.

Develop and improve products. List of Partners vendors. Share Flipboard Email. Anne Marie Helmenstine, Ph. Chemistry Expert. Helmenstine holds a Ph. She has taught science courses at the high school, college, and graduate levels. Facebook Facebook Twitter Twitter. Featured Video. Cite this Article Format. Helmenstine, Anne Marie, Ph. Percent Yield Definition and Formula. Theoretical Yield Definition in Chemistry.

Avogadro's Number Example Chemistry Problem. Calculating the Concentration of a Chemical Solution. Topics Typically Covered in Grade 11 Chemistry. Calculating Concentrations with Units and Dilutions.

How to Calculate Theoretical Yield of a Reaction. Your Privacy Rights.