Question

In the reaction of 1.23 g of salicylic acid (138.12 g/mol) with 2.79 g of acetic anhydride (102.10 g/mol), a student obtained 1.25 g of acetylsalicylic acid (180.17 g/mol). What is the percent yield?

Answer 1

The percent yield of acetylsalicylic acid is calculated to be 77.89% by first determining the theoretical yield using the amount of limiting reactant (salicylic acid) and then comparing it with the actual yield obtained.

Step-by-step explanation:

To calculate the percent yield of acetylsalicylic acid, we first need to determine the theoretical yield based on the limiting reactant. We begin by calculating the number of moles of salicylic acid and acetic anhydride based on their given masses and molar masses:

• Number of moles of salicylic acid = 1.23 g / 138.12 g/mol = 0.00890 mol
• Number of moles of acetic anhydride = 2.79 g / 102.10 g/mol = 0.0273 mol

Since the reaction is 1:1, salicylic acid is the limiting reactant. We use the moles of the limiting reactant to find the theoretical yield of acetylsalicylic acid:

• Theoretical yield = 0.00890 mol × 180.17 g/mol = 1.6045 g

The actual yield is given as 1.25 g. We calculate the percent yield using the formula:

Percent yield = (actual yield / theoretical yield) × 100

Percent yield = (1.25 g / 1.6045 g) × 100 = 77.89%

Therefore, the percent yield of acetylsalicylic acid in this reaction is 77.89%.