Introduction
When a person drinks tea or coffee, it is not pure caffeine. It also has other natural substances. The purpose of this lab was to isolate caffeine from tea leaves. The methylene chloride removed nearly pure caffeine from the basic tea solution. Caffeine is a white, crystalline, bitter alkaloid, C8H10N4O2 , usually derived from coffee or tea. Caffeine is used in medicine chiefly as a nervous system stimulant. Caffeine is used by humans to ward off drowsiness and restore alertness. Caffeine constitutes as much as 5% by weight of the leaf material in plants. The hypothesis for this experiment is that the observed melting point of the pure caffeine will be lower than the melting point of pure