Unformatted text preview: . The chloroform evaporated first so it was the one that was
collected as the distillate and the remaining liquid in the distilling flask contains the caffeine. The
remaining liquid in the distilling flask was further heated until all the chloroform evaporated leaving
An empty evaporating dish was weighed and it weighs 51.3522 g. After the caffeine crystals
were isolated, the evaporating dish containing the crystals wasweighed again. It weighed 51.3826 g .
By subtracting the weight of the crystals together with the evaporating dish and the evaporating dish
we can get the weight of the caffeine that was extracted. Its weight is 0.0504 g. Thus the percentage
yield of caffeine in the tea is1.42 %. The small amount of caffeine crystals that are obtained is
attributed to some errors occurred during the experiment. In our first trial of liquid-liquid extraction,
the solution that we extracted evaporated so in this experiment we only used the solution that we
extracted from the 2nd trial that is why the amount of caffeine crystals that we extracted is half of the
actual expected amount of the extracted caffeine. IV. CONCLUSION In order to isolate caffeine from tea, different types of extraction methods were done. T...
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This document was uploaded on 03/03/2014.
- Fall '14