The purpose of this experiment was to perform the separation of aspirin, sucrose and an unknown analgesic, which are constituents of Panacetin using the methods of filtration, extraction, and purification
Table of Reagents and Solvents:
Wt. or Vol.
MP or BP, ºC
Harmful if swallowed or inhaled.
DCM (35 mL + 5 mL +5 mL)
Harmful by skin contact and eye and skin irritant
5 % NaHCO3
Causes serious eye irritation
6 M HCl
Very corrosive and can destroy many clothing materials
2.014 g of Panacetin was measured and put inside a 125 mL Erlenmeyer flask. 35 mL of Dichloromethane (DCM) was added to the 125 mL Erlenmeyer flask. After addition of DCM the Panacetin lumps were crushed with a stirring rod. Next a fluted filter paper was pre-weighed. The filter paper weighed around .860 g. Gravity filtration was then used to filter the mixture into a 125 mL collecting flask. The mixture was filtered in order to separate the crude sucrose from the mixture. The original container was then rinsed through the filter paper again with 5 mL of DCM and the mass of filter paper containing sucrose was measured after it was dry. The last step was to perform the isolation of Aspirin. See image below.
The mixture of DCM and Panacetin were poured from the collecting flask into a seperatory funnel and two extractions were performed, using a total of 30 mL of 5 % NaHCO3. In the first extraction 20 mL of 5 % NaHCO3 was measured and poured into the seperatory funnel. A stirring rod was then used to stir the mixture until fizzing stopped. The seperatory funnel was then stoppered and shaken and the valve was gradually turned to allow the carbon dioxide to escape. The release of carbon dioxide made a hissing sound. This step was repeated once; the seperatory funnel was then placed into the lab hood and through a metal ring holder. The seperatory funnel was used to separate the organic layer from the aqueous layer which were found to be immiscble. Finally, the stopper was removed and the organic and aqueous layers were extracted into two different beakers. See image below.
The remaining 10 mL of 5 % NaHCO3 was added to the seperatory funnel in the second extraction. The mixture was stirred until the fizzing stopped and the seperatory funnel was stoppered and shaken, then the carbon dioxide was gradually released from the seperatory funnel by turning the valve. Two layers formed, the top layer was the unknown and it was denser than the aqueous layer that was underneath it. The organic layer which contained the unknown was poured into the same beaker as the organic layer from the first extraction and the aqueous layer which contained DCM was poured into the beaker containing the aqueous solution from the first extraction. The reason the extraction was performed was to separate the aspirin and the unknown.
3.5 mL of 6 M HCl was measured and 3.5 mL of HCl was added drop wise to the flask to make the pH of the aqueous solution less than 2, meaning the pH paper appeared as a pinkish color. During addition of the HCl, the aqueous solution formed a bubbly and cloudy white layer on top. Second, the mixture was placed into a cold ice bath for 10 minutes and the small filter paper was measured before using it for vacuum filtration. The purpose of using vacuum filtration was to collect the aspirin. The aspirator was left running until the aspirin was dried and the filter paper containing aspirin was weighed as 0.83 g. Next was the isolation of the unknown analgesic.
In part F Sodium sulfate was added to the organic mixture. The sodium sulfate was collected into a 100 mL round bottom flask...