Aspirin Synthesis Lab Report

Our data displayed supports the notion that by increasing the acidity of the catalyst, the production of aspirin will increase. Our hypothesis was proven correct. In our data, we calculated the percent yield and percent error of each trial. We also calculated the average of the percent yields and the percent errors of each catalyst. In the end, we saw that for the sulphuric acid catalyzed aspirin, we saw an average of 69.7% percent yield and an average 30.3% percent error. As for the phosphoric acid catalyzed aspirin, we saw an average of 55.0% percent yield and an average 42.2% percent error. The Ka value for sulphuric acid is 1.0 x 10³ while the Ka value for phosphoric acid is 7.1 x 10⁻³. Knowing that the Ka value denotes the acidity of
Because of the sigma bond present in the methane group, all the three hydrogens attached are constantly rotating. Because of this constant rotation, all the three hydrogens share one electronic environment. Also, the methane hydrogens are more shielded than compared to the other hydrogens. The carbon in the methane group is not as electronegative as the oxygen in the hydroxyl group and because there are three consecutive hydrogens adjacent to each other, more electron shielding prevails. Because the hydrogens in the methane group are more shielded, it will take less energy to bring the hydrogen(s) into resonance. With this, the chemical shift associated with these hydrogens will result upfield, i.e. lower ppm. Its peak is at 2.3469 ppm. The four hydrogens located on the benzene ring are associated with the four peaks located from 7.1495 ppm to 8.1064 ppm. These four peaks are all in a close range because all four hydrogens have somewhat similar electronic environments due to the fact that each one is bonded to one carbon. However, the placement of these hydrogens around the benzene ring, and the presence of neighboring functional groups, is what makes each hydrogen different, and so four peaks result. As for the OH hydrogen, it is not shown due to the fact that the OH is acidic enough that the hydrogen exchanges quickly with the solvent. The hydrogen dissociates and associates so quickly that the NMR machine cannot detect this. As a result, no peak is shown for the OH group. The hydrogen bonds and the interaction processes occur interrupt and skew any chemical shifts that would be observed in the NMR spectrum (Dollenmeier,