On a molecular basis the identification of the aspirin, acetaminophen, and caffeine via Rf values can be understood when looking at molecular symmetry and different functional groups. Caffeine had the lowest Rf value, with the caffeine crystals yielding a Rf value of 0.21. This is due to caffeine being the most polar molecules out of the three components. Caffeine has 4 Nitrogen atoms in the compound that are not symmetrically balanced out, along with two amide groups that are also not symmetric to each other. The amides and Nitrogen atoms make caffeine the most polar out of the three components, thus, causing caffeine to have the lowest Rf value. The middle Rf value out of the three was observed at 0.504 in acetaminophen. Meaning acetaminophen is more polar than aspirin, but not as polar as caffeine. …show more content…
We did the TLC to determine whether our predictions of our crystals were right by co-spotting with what we predicted each compound to contain. The TLC was successful in showing that we predicated each compound correctly because they co-spotted on the same horizontal line as the Excedrin component in them. Due to the different polarities of acetaminophen, aspirin, and caffeine they travelled different lengths up the plate, as discussed before, and this allowed for the overall success of TLC. The Rf values varied from about .21 for the caffeine, .50 for the acetaminophen, and .71 for the aspirin meaning we were able to easily differentiation whether our crystals and extracts contained one of the compounds. Due to the variety of polarity leading to a clear distinction in the Rf values of the three components, we were able to successfully use TLC to identify the compounds in each of our crystals and extracts. Thus, the TLC was an overall success; TLC was successful implemented in this lab as it was able to differentiation between the caffeine, aspirin, and acetaminophen in each of our crystals and