The English used in this article or section may not be easy for everybody to understand. (March 2012)
In chemistry, yield (also called chemical yield or reaction yield) is the amount of product resulting from a chemical reaction. The absolute yield gives the weight in grams, and the molar yield gives the number of moles.
The fractional yield, relative yield, or percentage yield shows how completely a synthetic procedure worked. It is calculated by dividing the amount of product by the theoretical yield (the unit of measurement for both must be the same):
To get the percentage yield, one must multiply the fractional yield by 100% (e.g., 0.673 × 100% = 67.3%).
The ideal percentage yield of a chemical reaction is 100%, but it cannot be achieved because measurements are never completely accurate. Yields around 100% are "quantitative", yields above 90% are "excellent", yields above 80% are "very good", yields above 70% are "good", yields above 50% are "fair", and yields below 40% are "poor".
- Vogel, A.I., Tatchell, A.R., Furnis, B.S., Hannaford, A.J. and P.W.G. Smith. Vogel's Textbook of Practical OrganicHall, 19936-3.