THEORETICAL ACTUAL AND PERCENT YIELD - PUNJAB-CURRICULUM-AND-TEXTBOOK-BOARD-PCTB / 10TH-CLASS / CHEMISTRY / HISTORY-OF-CHEMISTRY-10TH-CLASS-NBF-2024 / STOICHIOMETRY / THEORETICAL-ACTUAL-AND-PERCENT-YIELD

3.4 Theoretical Yield, Actual yield and Percent yield

The amount of product as calculated from a balanced chemical equation is known as the theoretical yield of a chemical equation. The actual yield is the amount of product actually produced in the reaction. The percent yield of a chemical reaction can be calculated as follows:

P e r c e n t a g e Y i e l d = \frac{A c t u a l Y i e l d}{T h e o r e t i c a l Y i e l d} \times 100

For many reactions, the theoretical yield is close to the actual yield. These reactions are quantitative and can be used for chemical analysis. For some reactions, however, the actual yield is below the theoretical yield, and the percent yield is less than $100\%$ . This is because of the following reasons:

Side reactions may result in by- products. Some reactions may be reversible. Mechanical loss can occur as a result of filtration or distillation. Separation by a funnel, washing or crystallization can also cause mechanical loss.

Example 3.5

In an industry copper metal was prepared by the following reaction,

F e_{(s)} + C u S O_{4} (a q) ⟶ F e S O_{4} (a q) + C u_{(s)}