When you carry out a chemical reaction in the lab, it’s important to know how much product you’ll get out of it. The amount of product you actually get is called the actual yield, while the theoretical yield is the maximum amount of product you could get if everything goes perfectly. Let’s take a closer look at both of these concepts.
The theoretical yield is the amount of product that would be produced if the reaction proceeded under ideal conditions. In other words, it’s the maximum amount of product that could be produced from a given amount of reactants. However, it’s rare to achieve this yield in practice because there are many factors that can affect the reaction.
Some reasons why the theoretical yield is difficult to obtain include:
The actual yield is the amount of product you actually obtain from the reaction in the lab. The actual yield is always less than or equal to the theoretical yield because it’s rare to achieve ideal conditions in the lab.
However, if everything in the lab goes perfectly (a rare occurrence), the two yields can be the same.
We can calculate the percentage yield using this equation:
The percentage yield is a measure of the efficiency of a chemical reaction. It tells us how much of the expected product we actually obtained. The formula for calculating percentage yield is:
In an experiment, aluminium oxide reacts with sulfuric acid to form aluminium sulfate and water. The balanced equation for the reaction is:
Aluminium oxide + Sulphuric acid → Aluminium sulfate + Water
Al2O3 + 3H2SO4 → Al2(SO4)3 + 3H2O
The reaction formed 2.4 g of dry aluminium sulfate crystals. If the theoretical yield is 3.0 g, calculate the percentage yield of aluminium sulfate.