Question

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

Answer 1

Hint: Yield is a measure of the quantity of moles of a product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage. Yield is one of the primary factors that scientists must consider in organic and inorganic chemical synthesis processes.

Complete answer:
Theoretical yield: The theoretical yield is the maximum amount of product that can be formed in a chemical reaction based on the amount of limiting reactant.
Actual yield: An actual yield is the mass of a product actually obtained from the reaction. It is usually less than the theoretical yield.
Percent yield: Percent yield is the percent ratio of actual yield to the theoretical yield. It is calculated to be the experimental yield divided by theoretical yield multiplied by $ 100\% $ .
In symbols:
 $ \Rightarrow Percent\; yield= \dfrac{{actual\;yield}}{{theoretical\;yield}} \times 100 $
Actual yield in a reaction is almost always less than the theoretical yield, primarily because losses of the substance involved may occur anywhere in an experiment. Of course, a true actual yield can never be greater than the true theoretical yield in a reaction, the possible occurrence in your reaction.
Also, experimental error can occur, and if you successfully remove all of them, that’s the you would have your true actual yield. For example you weighed what seemed like a dry filter paper containing your precipitate, but it may actually have some water in it you still haven’t removed that can contribute to more weight of the sample. Error from the apparatuses and instruments you have used but you didn’t notice can also add up, making it possible to get $ 110\% $ actual yield.

Note:
The actual yield is always smaller, often very much so, for several reasons. As a result, many reactions are incomplete and the reactants are not completely converted to products. If a reverse reaction occurs, the final state contains both reactants and products in a state of chemical equilibrium.