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[SOLVED]CHEM 2101 Experiment 5

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Experimental: Week 1: In the first week of the experiment we started by boiling 100 mL of distilled water in a 400 mL beaker on a hot plate. After the water came to a boil the beaker was removed and... the three tea bags, which were previously weighed, were added to the hot water and the contents were stirred for approximately two minutes. The tea bags were then removed and placed between two watch glasses to squeeze as much liquid as possible out of them before disposing of the tea bags. The solution was then cooled by swirling the flask in cold water and placed into a seperatory funnel. This set up was found in appendix M. 20 mL of dichloromethane was added to the funnel. The contents were stirred and vented according to the procedure in appendix M. The layers were allowed to separate and then the bottom layer of dichloromethane was drained into a clean 125 mL Erlenmeyer flask. This step was repeated two more times. Then the aqueous layer was poured out the top of the funnel into a labelled beaker. The approximately 60 mL of dichloromethane extracts were returned to the funnel and extracted twice with 20 mL of cold 6M NaOH. It was important to note that the aqueous layer was on top and the caffeine was in the dichloromethane layer, which was on the bottom. Each time we withdrew the dichloromethane layer into the labelled flask and the water into the labelled beaker. Afterwards, we put the dichloromethane layer back into the seperatory funnel for the next wash. Finally, we washed the dichloromethane with 20 mL of cold distilled water, and the dichloromethane was poured into a clean Erlenmeyer flask. A teaspoon of the drying agent was added. The flask was swirled and stood for five minutes and was then decanted into another flask. In the fume hood, the dichloromethane was removed by heating very gently on a hotplate. Off-white crystals formed and the weight of the crude product was obtained. The melting point was also calculated [Show More]

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