Question

Aspirin is prepared by reacting salicylic acid with excess ethanoic anhydride. in an experiment, 50.05 g of salicylic acid was converted into 55.45 g of aspirin. what was the percentage yield

Answer 1

The balanced reaction would be written as:

C7H6O3 + C4H6O3--->C9H8O4 + HC2H3O2

To determine the percent yield, we need to first determine the theoretical yield if the reaction were to proceed completely. Then, we divide the actual yield that is given to the theoretical yield times 100 percent. The limiting reactant from the reaction would be salicylic acid. We do as follows: 

Theoretical yield: 50.05 g C7H6O3 ( 1 mol / 138.21 g ) ( 1 mol C9H8O4 / 1 mol C7H6O3 ) ( 180.157 g / mol ) = 65.24 g C9H8O4 should be produced

Percent yield = 55.45 / 65.24 x 100 = 84.99%

Therefore, the percent yield for the given amount of salicylic acid is 84.99%