Define the terms theoretical yield, actual yield, and percent yield. Why is the actual yield in a reaction almost always less than the theoretical yield? Can a reaction ever have 110% actual yield?

Question

Define the terms theoretical yield, actual yield, and percent yield.  Why is the actual yield in a reaction almost always less than the theoretical yield? Can a reaction ever have 110% actual yield?

Mateo Aguilar · Accepted Answer

Theoretical yield - amount that can be produced as found from correct computations
Actual yield - actual amount produced in the experiment
Percent yield - quotient of the absolute value of the difference of actual and theoretical yield and the theoretical yield multiplied by 100%. In symbols, # ext{Percent yield} = \frac{\abs{ ext{theoretical}- ext{actual}}}{ ext{theoretical}} imes100\%#
(Other answers are in explanation)

Actual yield in a reaction is almost always less than theoretical yield, mainly because losses of the substances involved can happen anywhere in an experiment. If not, there are a plethora of reasons that can be given depending on the reaction, such as the possibility of the reactants' exposure to one another decreasing as the amount of products increases, though this may not hold true for all reactions. Other factors that may contribute to this phenomenon include temperature, water content, and the reactants' nature. Naturally, a "true" theoretical yield in a reaction can never be higher than a "true" actual yield (this is the response to your previous question). What I mean by a "true" theoretical yield is the theoretical yield in which you have taken into account EVERY possible scenario in your reaction. For instance, if you were unaware that contaminants in your reaction container could react with your desired product to produce the same reactant again, then it's possible that the theoretical yield you calculated will differ from the "true" theoretical yield that should be taken into account. It is impossible to have a higher theoretical yield than actual yield if your calculations were accurate because that would be against the Law of Conservation of Mass, which states that "the total mass of the reactants must be equal to the total mass of the products." ===== OTHER INFORMATION==== Additionally, experimental errors can happen; if you are able to eliminate them all, that is when you will have your "true" actual yield. For instance, you may have weighed what appeared to be a dry filter paper containing your precipitate, but in reality, it may contain some additional water that you haven't yet removed, which could add to the sample's weight. Additionally, errors from the apparatuses and instruments you have used that you were unaware of could accumulate and result in an actual yield of 110%.

Jeremiah Adams · Answer

undefined Theoretical yield: The maximum amount of product that could be obtained in a reaction based on stoichiometry.

Actual yield: The amount of product obtained from a reaction in a practical experiment.

Percent yield: The ratio of actual yield to theoretical yield, expressed as a percentage.

The actual yield is often less than the theoretical yield due to factors like incomplete reactions, side reactions, or loss during the experiment. A reaction cannot have a 110% actual yield; it exceeds the theoretical maximum, indicating experimental errors or inaccuracies.