Final answer:
Percent recoveries in experiments are commonly under 100% due to losses such as spills or side reactions; yields over 100% may indicate impurities or errors. Good percent yields range from 80%-90%, reflecting successful laboratory practices or efficient industrial processes. The percent yield quantifies the success of a reaction, comparing actual and theoretical outputs.
Step-by-step explanation:
When discussing percent recoveries in experiments, it is important to recognize that they are typically less than 100% due to various factors, such as mechanical losses, side reactions, and incomplete reactions. A percent yield greater than 100% can suggest impurities or measurement errors, while a yield significantly lower than 100% may indicate procedural issues or that the reaction did not proceed to completion.
In laboratory settings, a perfect recovery with a percent yield of 100% is improbable, much like the example of trying to pour salt into a shaker without spilling. Most times, certain amounts of product get lost in the process. A yield of 0% indicates that no product was obtained, which is a clear sign of an unsuccessful reaction. Yields between 80%-90% are generally regarded as good to excellent, while 50% is fair. In the industrial context, there is a significant push towards high efficiency to reduce waste and costs.
The actual yield is the amount of product actually obtained from a reaction, while the theoretical yield is the maximum amount predicted by stoichiometry. To determine the percent yield, the formula used is actual yield (g) × 100% / theoretical yield (g). This percent yield is a critical measure of the reaction's success.