Chapter 3, Problem 3.125QP

Aspirin or acetyl salicylic acid is synthesized by reacting salicylic acid with acetic anhydride:

$\underset{\text{salicylic}\text{acid}}{{\text{C}}_7{\text{H}}_6{\text{O}}_3}+\underset{\text{acetic}\text{anhydride}}{{\text{C}}_4{\text{H}}_6{\text{O}}_3}\stackrel{}{\to }\underset{\text{aspirin}}{{\text{C}}_9{\text{H}}_8{\text{O}}_4}+\underset{\text{acetic}\text{acid}}{{\text{C}}_2{\text{H}}_4{\text{O}}_2}$

(a) How much salicylic acid is required to produce 0.400 g of aspirin (about the content in a tablet), assuming acetic anhydride is present in excess? (b) Calculate the amount of salicylic acid needed if only 74.9 percent of salicylic acid is converted to aspirin. (c) In one experiment, 9.26 g of salicylic acid is reacted with 8.54 g of acetic anhydride. Calculate the theoretical yield of aspirin and the percent yield if only 10.9 g of aspirin is produced.