Answer :
The yield of a reaction is the final product. It is necessary to find the percent yield of a reaction since the efficiency of the reaction can be determined.
Explanation:
Percent yield is defined as the percent ratio of experimental yield by the theoretical yield. The equation used to calculate this quantity is given by:
[tex]\text{Percent yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100[/tex]
This is necessary because during a reaction, many by-products are formed along with the required product. So, to judge the product we require this. This is very important in the synthesis of the product. This is also used to detect if there is any impurity in the product or not.
Like, if the percent yield is more than 100%, it means that the product carry some impurity in it and it has to be removed. This is also used to know that if all the reactants have reacted together or not.
Hence, knowing percent yield helps in many ways.