The actual yield of product is the quantity of product that is generated in the chemical reaction as all the quantity of the compounds reacting are not consumed completely.
And the theoretical yield of product is the quantity of product that will be produced suposing that the compounds reacting were consummed completely.
The percentage of yield in a chemical reaction can be measured by the relationship between the actual yield of product and the theoretical yield of product in the following way:
%yield =
Replacing the quantities the problem gives you, we have:
The machine whose efficiency is 100% is known as perfect machine .This machine is not possible in real life because every machine is affected by the overcoming friction due to which is efficiency become less than hundred percent .