Pencil and Paper Activity:
Aspirin Math for High Schoolers

All the following questions and calculations assume the aspirin tablet(s) in question contain 325 mg of acetylsalicylic acid (ASA) in each tablet.

1. How many tablets can be made from 1 kg of acetylsalicylic acid? Round your answer to the nearest whole number.

2. How many moles of ASA are contained in that 1 kilogram? The formula for ASA is C₉H₈O₄.

3. How much sodium hydroxide (NaOH) would be needed to neutralize 50 grams of ASA?

4. In the lab you synthesized aspirin according to the reaction given below. Acetylsalicylic acid (ASA) is synthesized by the addition of acetic anhydride to salicylic acid (SA). Acetic acid is the second product (sometimes called a by-product) of the reaction.
   
   1. Calculate the mass of salicylic acid needed to make 1 aspirin tablet.

   2. Calculate the mass of acetic anhydride needed to produce 1 kg of ASA.

5. Today aspirin is made from crude oil, not willow bark. But if we did use willow bark, 1 kilogram of willow bark could produce about 27 grams of aspirin.
   1. Since one can only strip about 91 kg of bark from a willow tree without killing it, how many 325 milligram tablets of aspirin could be made from one willow tree?

   2. How many willow trees would it take to make the 80 million aspirin tablets consumed each day in the United States alone?

   3. Given that one acre of wet ground can support about 15 willow trees, how much land would be needed to produce one day's supply of aspirin for the United States?