Final answer:
Real yields or actual yields are the amounts of product actually obtained from a reaction, while theoretical yields are the amounts expected based on calculations. Percent yield, calculated by dividing the actual yield by the theoretical yield and multiplying by 100, measures the efficiency of the reaction.
Step-by-step explanation:
Real yields, also known as actual yields, refer to the amount of product that is actually obtained from a chemical reaction, as opposed to the theoretical yield, which is the calculated amount of product expected based on the balanced chemical equation. The percent yield is a measure of the efficiency of a reaction, expressed as a percentage, and is calculated by taking the actual yield, dividing it by the theoretical yield, and multiplying by 100%. Percent yields are important because they help chemists understand how well a chemical reaction has proceeded and identify areas where improvements can be made.
For example, if a reaction theoretically produces 50 grams of product but in reality only 40 grams are obtained, the actual yield would be 40 grams, and the theoretical yield would be 50 grams. The percent yield would then be calculated as (40 grams / 50 grams) × 100%, which equals 80%. This tells you that the reaction was 80% efficient.
Percent yields matter because they allow for the comparison of experimental results to the expected outcomes, aid in the optimization of reaction conditions, and ensure resources are used efficiently in industrial processes.