Asprin Experiment on Blackboard

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Aspirin was prepared according to the protocol provided on Blackboard. The three sections to this experiment were 1. Synthesis of Aspirin, 2. Recrystallization of Aspirin, and 3. Characterization of Aspirin. In the first section, the Synthesis of Aspirin, salicylic acid was weight to be 3.029 grams using mass by difference since it was weighed on a 150 milliliter beaker. 9.23 milliliters of the acetic anhydride and 14 drops of 85 percent phosphoric acid were added to this beaker. A Bunsen burner provided by the laboratory was then used to boil the just mixed combination by producing a flame underneath the positioned beaker on top, and then allowed to cool for several minutes after the Bunsen burner flame was terminated. Two quantities of distilled water were then added to this mixture to make it cool even further, which were 41 drops and 30 milliliters. After cooling for some time, this beaker was placed into an ice bath in order to start the crystallization process. A glass rod was used to scratch around the bottom and the sides to catch all of the crystallized Aspirin that was being formed during this whole process. Then, by using a Buchner funnel and filter paper, which was placed on top of the flask connected to a water aspirator with rubber tubing, the excess liquid was removed from the just scraped Aspirin crystals when the Aspirin was placed on the filter paper. Using a medicine dropper, the Aspirin crystals on the filter paper were washed with distilled water just so that any non-pure substances were removed from the crude product. When these crystals were then ultimately dry, they were placed on a watch glass and put into an oven for 30 minutes. Then they were weighed by mass by difference to yield 2.4667 grams of crude s... ... middle of paper ... ...s the change in the temperature of both of these batches, 6°C for the pure, and 13°C for the crude. In this final sub-section of the Characterization of Aspirin, the values of absorbance were recorded. Initially, 0.0566 grams and 0.0590 grams of pure and crude Aspirin respectively were obtained and each individually placed into beakers (400 milliliter) and had 250.0 milliliters of distilled water added to them. From each beaker, a tiny amount of the just dissolved solutions was transferred to a cuvette, one cuvette for each type of aspirin. Each cuvette was placed into the ultraviolent spectroscopy mechanism which was connected to a computer and absorbance spectrum values were obtained at 298 nm (Figure 5) (0.1987 pure aspirin, and 0.9549 crude aspirin). Cumulatively these three methods resulted in the determination of the percent purity for each type of aspirin.

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