Chemistry classes create aspirin for lab

Jason+Shim+%2810%29+observes+a+beaker+while+participating+in+the+AP+Chemistry+lab.+Students+in+the+classes+created+aspirin+during+a+lab+from+Oct.+6+to+Oct.+10.+

Andrew Liang

Jason Shim (10) observes a beaker while participating in the AP Chemistry lab. Students in the classes created aspirin during a lab from Oct. 6 to Oct. 10.

by Andrew Liang and Kinnera Mulam

Students in upper school chemistry teachers Dr. Mala Raghavan and Dr. Casey Brown’s Advanced Placement (AP) chemistry classes created aspirin during a lab from Oct. 6 to Oct. 10. 

On the first day of the lab, students mixed salicylic acid and acetic anhydride to create a clear solution called acetylsalicylic acid, also known as aspirin. To crystalize the aspirin compound, lab partners then placed their beakers of solution into an ice bath, and after around 10 minutes, students saw aspirin crystals settling to the bottom of their beakers and collected the crystals after filtration. The students waited until the next class period for the aspirin to dry and evaluate their yield, since massing the wet compound would result in inaccurate results. Some students, including Nelson Gou (10), found this process of creating aspirin from raw materials unexpectedly easy.

“I assumed [the process] would just be super complex and you had to like to mix a ton of stuff,” Nelson said. “But it was easier than I thought it would be.” 

In the next class period, lab partners determined the purity of their aspirin through two tests: thin-layer paper chromatography and the iron chloride test. More salicylic acid in a student’s aspirin corresponded with higher impurity. All tests required students to compare the amount of salicylic acid in their own aspirin with the amount in commercial aspirin, which is completely pure. 

With thin-layer chromatography, students put the three substances onto a paper coated with silica gel and allowed a fluid to wash away the substances. Depending on how fast different compounds traveled, students could identify how much salicylic acid ended up in their aspirin. 

The second test also used the same three samples, but students pipetted a drop of iron chloride into the three compounds. In this case, the darker the solution, the more impure the sample was. 

This lab served as hands-on practice by requiring students to use the knowledge learned from class to draw inferences and conclusions. 

“This was helpful in applying the [concepts] we learned in class,” Nelson said. “I just didn’t really know you could synthesize a drug. Not every drug is made this way obviously but it [was] cool to see it [happen].” 

Dr. Mala Raghavan observes Yasmin Sudarsanam (10) in a demonstration for the aspirin lab. This lab served as hands-on practice by requiring students to use the knowledge learned from class to draw inferences and conclusions. (Andrew Liang)