Hands-on Activity:
Making Aspirin
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Purpose
To synthesize aspirin (ASA) from salicylic acid (SA) and test the product for purity. |
Purpose and Introduction |
Introduction
In this experiment, you are going to re-create the work of Felix Hoffmann and Arthur Eichengrün for yourself. You will prepare aspirin (acetylsalicylic acid) beginning with salicylic acid and acetic anhydride.
It is important, while you are mixing materials together and carrying out the reaction, to understand what the molecules of those materials are doing. By mixing and heating the materials, we make their molecules do some interesting things. You might think of what you're doing as taking off one part of a molecule and replacing it with something else, like you see in the picture below where the blue square is removed from the molecule and replaced with a red triangle. Or click here to watch a movie of this "reaction."
(Notice that there are the same number of blue squares and red triangles on each side of the equation. Also, notice that the "leftover" blue square and red triangle have combined to form a byproduct molecule.) A more accurate picture of what is going on at the molecular level is given in the following equation.
