Percent yield is calculated using the formula: $\text{Percent Yield} = \left( \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \right) \times 100$.
Actual yield is the amount of product actually obtained from a reaction.
Theoretical yield is the maximum amount of product that could be formed from given reactants, based on stoichiometric calculations.
Percent yield can never exceed 100% because it would indicate more product was obtained than theoretically possible, suggesting an error or contamination.
A low percent yield may indicate incomplete reactions, side reactions, or loss of product during recovery.
Review Questions
What is the formula for calculating percent yield?
Why can percent yield never exceed 100%?
What might a low percent yield suggest about a chemical reaction?
Related terms
Actual Yield: The quantity of product that is actually produced in a chemical reaction.
Theoretical Yield: The maximum amount of product that could be formed from given reactants based on stoichiometric calculations.
Stoichiometry: The part of chemistry that deals with the relative quantities of reactants and products in chemical reactions.