# percent yield

(noun)

## Definition of percent yield

referring to the efficiency of a chemical reaction; defined as the actual yield/theoretical yield * 100

Source: Wikipedia - CC BY-SA 3.0

## Examples of percent yield in the following topics:

• ### Calculating Theoretical and Percent Yield

• To evaluate the efficiency of the reaction, chemists compare the theoretical and actual yields:percent yield = actual yield/theoretical yield * 100$% yield = (actual yield/theoretical yield) * 100$To calculate yield using this equation, it is not necessary to use a particular unit of measurement (moles, mL, g etc.), but it is important that the two values you are comparing are consistent in units.
• The theoretical yield of a reaction is 100 percent, but this value becomes nearly impossible to achieve due to limitations in measurement accuracy.To accurately calculate the yield, you must first balance the chemical equation.
• Then the theoretical yield of the product can be determined and, finally, compared to the actual yield.
• *\frac{123.1 g C_6H_5NO_2}{1mol C_6H_5NO_2}=24.6 g C_6H_5NO_2\$Therefore, if all C6H6 were converted to product and isolated, we in theory should obtain 24.6 grams of product (100 percent yield).
• If 18.0 grams were isolated, we could calculate the percent yield:percent yield=18.0g/24.6g *100percent yield=73.2%
• The percent yield of a reaction measures the efficiency of a reaction.
• ### Amount of Reactants and Products

• In addition, stoichiometry can be used to find quantities such as the amount of products that can be produced with a given amount of reactants and percent yield.
• ### Reaction Stoichiometry

• For example, in a reaction that forms ammonia (NH3), exactly one molecule of nitrogen (N2) reacts with three molecules of hydrogen (H2) to produce two molecules of NH3:N2 + 3H2 → 2NH3Stoichiometry can be used to find quantities such as the amount of products (in mass, moles, volume, etc.) that can be produced with given reactants and percent yield (the percentage of the given reactant that is made into the product).