Which measurements are required to calculate the percent yield for a reaction?

To calculate the percent yield of a reaction, it is essential to compare the actual amount of product obtained from the reaction with the theoretical amount of product expected based on the starting material used in the reaction. In this case, the mass of the recrystallized product represents the actual yield, whereas the mass of 4-aminophenol serves as the starting material from which the theoretical yield is calculated.

Percent yield is determined using the formula:

[ \text{Percent Yield} = \left( \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \right) \times 100 ]

Here, the actual yield is the mass of recrystallized product, while the theoretical yield can be derived based on the stoichiometry of the starting material, which in this instance is 4-aminophenol. This demonstrates that both measurements are crucial in determining the efficiency of the reaction and providing insight into how much of the expected product was actually formed.

The other options do not incorporate both necessary components for the calculation of percent yield in the same way: the necessary contrast between the actual product obtained and the theoretical yield based on starting materials.