What does a percent recovery greater than 100% most likely indicate in an experiment?

• A. The product was lost during the procedure.
• B. The experiment was performed with perfect accuracy.
• C. The theoretical yield was underestimated.
• D. The sample was contaminated with impurities.

Answer: (D)

Verified step by step guidance

1. Understand that percent recovery is calculated by comparing the mass of the recovered product to the initial mass of the sample, using the formula: \(\text{Percent Recovery} = \left( \frac{\text{Mass of Recovered Product}}{\text{Initial Mass of Sample}} \right) \times 100\%\).
2. Recognize that a percent recovery greater than 100% means the recovered mass is larger than the initial mass, which is physically unexpected if the sample is pure and no additional material is added.
3. Consider possible reasons for this anomaly, such as contamination of the sample with impurities that add extra mass, leading to an artificially high recovery percentage.
4. Rule out other options: loss of product would cause less than 100% recovery, perfect accuracy would yield around 100%, and underestimating theoretical yield relates to percent yield, not percent recovery.
5. Conclude that a percent recovery greater than 100% most likely indicates the sample was contaminated with impurities, increasing the measured mass beyond the original amount.