Calculating Percent Yield and Recovery Correctly

Percent yield and percent recovery are related but distinct calculations, and mixing up the theoretical basis for each is a common source of confusion, especially between synthetic chemistry and purification/extraction contexts.

Percent yield (synthesis)

Theoretical yield is the maximum possible product calculated from stoichiometry, assuming the limiting reagent reacts completely with no losses. Actual yield is what you actually isolated and weighed. The ratio tells you how efficiently the reaction — and your purification — actually performed.

Finding the limiting reagent first

Before calculating theoretical yield, you need to identify which reactant limits the reaction — the one that runs out first based on the stoichiometric ratio in the balanced equation, not necessarily the one with the smallest mass or volume.

Percent recovery (purification/extraction)

This is different from synthesis yield — recovery compares what you get back after a purification step (recrystallization, extraction, column chromatography) to what you started with, not to a stoichiometric theoretical maximum. There's no chemical reaction changing the amount of your target compound; the question is purely how much you lost to the process itself.