Experiment 1 Separating the Components of Panacetin PDF

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CH 237 Lab for Experiment 1 of Separating the Components of Panacetin....

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Brooklynn Carlson Experiment 1 CH 237-0013 Experiment 1: Separating the Components of “Panacetin” Introduction: In this experiment, the focus was to separate the components of Panacetin and identify the unknown component from one of the two samples given. A label on a bottle of Panacetin lists the ingredients as aspirin, acetaminophen, and sucrose. The objective was to find out if the sample given was counterfeit or not. This was done by using gravity filtration to separate the sucrose, then using vacuum filtration of the aqueous layer produced by filtrating the sucrose. From there, vacuum filtration was used to separate the aspirin component. With the use of recrystallization and vacuum filtration, the unknown component could be separated. Results: The experiment yielded 0.80 grams of sucrose, 0.99 grams of aspirin, and 0.40 grams of the unknown. The total weight that was recovered was 2.19 grams with the original weight at 3.001 grams. Panacetin is 36.53% sucrose(.80g/2.19g), 45.21% aspirin(.99g/2.19g), and 18.26% unknown(.4g/2.19g). As the initial amount of Panacetin was 3.001 grams, it can be determined that the amount of Panacetin that should have been recovered is 1.09 grams of sucrose(.3653x3.001g), 1.36 grams of aspirin, and 0.55 grams of unknown. Using the equation wt component/wt Panacetin used, sucrose had a 26.66% recovery(.80g/3.001g). Aspirin had a 32.99% recovery (.99g/3.001g) and the unknown had a 13.33% recovery(.40g/3.001g). A total of 72.98% of Panacetin was recovered. The melting range for the unknown by itself was 101109℃. While the melting range for the unknown mixed with acetanilide was 82-95℃, and the melting range for the unknown mixed with phenacetin was 101-109℃. Discussion: The main objectives of this experiment were to separate the components of Panacetin and determine what the unknown component of our sample was. The data can then be used to figure out if the sample was counterfeit. The expected values of Panacetin can be found in the book. The expected values are 0.2g of aspirn, .05g of sucrose, and .25g of acetaminophen/theunkown for the experiment.The book also states how the values of 8-12% sucrose, 35-45% aspirin, 45-55% of the unknown essentially make up the composition of Panacetin and match the label. However, the results of the experiment do not match the compostions on the label of Panacetin. In the experiment, the compostions were 36.53% sucrose, 45.21% aspirin, and 18.26% of the unknown. Throughout the experiment, errors must have been made in the technique in order to get this drastic difference of results. Only a total of 72.98% of Panacetin was recovered out of the original 3.001g that were taken in the beginning. The parts that were recovered were the pure components of Panacetin. The 27.02% of lost Panacetin could be explained through several mistakes or different factors during the experiment. One common way where material could have been lost is during the removal of substances from containers or filter paper. This especially could be a big factor because filter paper can be difficult to obtain all material off it. Some of the sucrose could have been left in the flask after filtration as well as some aspirin got stuck on in the flask and on the stirring rod. For the unknown, it could have been how it got stuck in the round bottom flask after using the RotoVac and theres no way to

scrape all the sides due to the roundness. By not removing the material fully from all the filter papers and flasks could have a significant decrease in the measured percent composition and can explain for the lower recovered Panacetin. The unknown component of sample 2 of Panacetin was Phenacetin. This can be proven by the melting points of the unknown and the mixture of the unknown with Phenacetin. The melting point of Phencetin is 133-136℃ . The unknown melting point was measured to be 101-109℃ which is lower than that of Phenacetin. This can be a result of technical error. When measuring the boiling point of the mixture of the unknown with Phenacetin the melting point range was also 101-109℃ . This is clearly an identical measurement compared to the unknown melting point when tested alone. Since the melting point ranges are so close together, this has led to the conclusion that sample 2 of Panacetin is Phenacetin. There is a signiciant decrease in melting points between experimental unknown and the expected Phenacetin melting point. This means the experimental unknown had impurities when it was melted causing the melting point to be lowered. Based on the data recovered, it can be concluded that the second sample of Panacetin was counterfeit and the third component was Phenacetin based off of the melting points matching. This conclusion is supported by the fact that the melting point of the mixture of the unknown and Acetanilide was drastically different than the melting point of the unknown alone. The large differences in the compositions also support the conclusion that the Panacetin is counterfeit. Even though most of the data leads to the conclusion that the Panacetin is counterfeit, there is the chance that these results are not completely accurate due to technical error throughout the experiment that could have led to the differences. Conclusion: The unknown component for sample 2 is phenacetin, and the panacetin is counterfeit. This can be determined from the differences in melting points. Questions: 1) If after adding dichloromethane to Panacetin, the mixture was not stirred or shaken long enough then there would be some components that did not dissolve complete. This would cause the the components to be left with the sucrose which would increase the percent of sucrose after gravity filtration. Also, if during the NaHCO₃ extraction, the failure to mix the aqueous and organic layers thoroughly, then some of the aspirin could be found in the organic layer. This would cause the unknown percentage to increase while also decreasing the percentage of aspirin found in the final product. In addition, if you accidentally extract the dichloromethane solution with 5% HCl rather than 5% NaHCO₃, then the separation of the aqueous layer would not fully work. This would also result with aspirin being left in the organic layer causing an increase in the percentage in the unknown and a decrease in the percentage of aspirin recovered. 2) If there is failure to dry the product completely, then the yield of the product would be increased from the extra weight the moisture would cause. This would also cause the product to be not completely pure because it would be a mixture of the component and the moisture. If you used enough water to recrystallize phenacetin, but your unknown was acetanilide, there was too much solvent used, as it takes more water to recrystallize phenacetin than acetanilide. This would decrease the yield. If all the aspirin was not extracted from the Dichloromethane, then the yield would be higher for the unknown

since there is added weight from the extra aspirin, This would cause the melting point to be lower due to the impurity of aspirin being mixed in....