Final answer:
Percent yield is the ratio of the actual yield of a product from a chemical reaction to its theoretical yield, expressed as a percentage. It often falls below 100% due to factors like inefficient reactions, side reactions, and product loss; though it can exceed 100% if impurities are present.
Step-by-step explanation:
Understanding Percent Yield
When discussing percent yield, it's important to differentiate between the theoretical yield and the actual yield. The theoretical yield is the maximum amount of product that can be produced from a chemical reaction, based on stoichiometric calculations using the balanced chemical equation. However, the actual yield is the amount actually obtained from the reaction. It is typically less than the theoretical yield due to a variety of factors such as inefficient reactions, side reactions, incomplete reactions, and losses during product recovery. The percent yield is the ratio of the actual yield to the theoretical yield, multiplied by 100, and provides insight into the efficiency of a reaction.
Chemists aim to optimize the percent yield to get as close to the theoretical yield as possible. However, due to experimental challenges
such as mechanical losses, competing reactions, and reactions not going to completion, achieving the theoretical yield is not always possible. In practice, any percent yield lower than 100% is expected, although yields greater than 100% can occur if the product contains impurities.
The formula to calculate the percent yield is:
percent yield = (actual yield / theoretical yield) × 100%