Date of experiment: September 3rd, 2013
Organic Chemistry II – CHLB330
Name: Symone MoxeyLab Partner: Lynden Cooper
Isolation of caffeine from tea leave
Caffeine is probably the most commonly used addictive drug. This drug is found in a number of things ingested by people. It belongs to a group of nitrogen bases called purines. Because caffeine possesses these base-like properties, it is described as an alkaloid. They usually taste bitter and often are physiologically active in humans. The structure of caffeine is shown below.
Figure 1: Structure of Caffeine
In this experiment, you are going to make a small but strong cup of tea and extract the caffeine from it. Also, you are going to purify the caffeine by recrystallization and calculate the mass percentage of caffeine in the tea sample using the equation below. Mass % = (wt. of purified caffeine / wt. of tea sample) x 100 Caffeine is a very common substance and is found in coffee, tea, soft drinks, chocolate, and "stay-awake" pills such as Vivarin. In Humans, Caffeine acts to stimulate the heart, central nervous system, and the respiratory system. Blood pressure is increased by its use, since heart rate is increased, as is contraction force and volume output. It is a diuretic and has the effect of delaying fatigue. Caffeine has a bitter taste. The isolation of Caffeine from tea is a simple-seeming experiment, which in fact makes use of a number of rather advanced chemical processes. To isolate the Caffeine in a sample of tea, it is necessary to chemically separate the Caffeine from the rest of the tea prior to evaporation. This process is known as an extraction. An Extraction is a chemical method of separating a specific component of a solution from the rest of the solution. This is done by using a solvent (in this case Chloroform) in which the substance to be isolated is very soluble, while the rest of the solution is not as soluble. For the purposes of this...
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