Percent Yield, Theoretical Yield, and Actual Yield

The formula above represents the percent yield, which is the ratio of the actual yield to the theoretical yield expressed as a percent

• The theoretical yield represents the maximum amount of product that can be formed from given amounts of reactants

• The actual yield is the amount of product that actually forms when the reaction is carried out (in the laboratory). It is considered as an experimental value.

The actual yield is generally less than the theoretical yield. Therefore, the % yield is less than 100%

Some reasons to why the % yield is less than 100%

• Reactions do not always go to completion
• Impure reactants and competing side reactions can produce unwanted products to form
• Products can be lost during processes such as during filtration or transferring
• Miscalculations in measurement

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