Category : Chemisty

Simple and Fractional Distillation

The purpose of this experiment was to separate two liquids using Simple and Fractional Distillations. Separation by distillation works by manipulating the chemicals’ colligative properties and intermolecular forces. Reagents in the Experiment: Cyclohexane Toluene                                               Analysis: This experiment attempted to separate two liquids, cyclohexane and toluene. These chemicals have different intermolecular forces and therefore have dissimilar boiling points. […]

Isolation of Caffeine from Tea

The purpose of this experiment was to practice fundamental laboratory techniques by isolation of caffeine, from tea leaves. Camellia sinensis (tea) Caffeine Analysis (Isolation of Caffeine) This experiment was conducted to study the simple isolation of an alkaloid and to train with fundamental laboratory equipment like the separatory funnel and distillation apparatus. Ten commercial tea bags (23.06 grams) were used for the extraction. Boiling water (~275 mL) was used to extract caffeine from the solid leaves. This was the most efficient solvent […]

Thin Layer Chromatography with Plant Pigments

Thin layer chromatography is an important analytical test for identifying unknown compounds, monitoring reactions, and testing chemical purity. The purpose of this experiment was to acquire the TLC technique. Chlorophyll: a common plant pigment Analysis Thin-layer chromatography (TLC) is an essential analytical technique for organic experiments. It is a quick and simple method for determining the number of compounds in a mixture, identifying an unknown, testing purity, and monitoring reactions. These tests occur on chromatographic sheets, commonly constructed of alumina […]

Acid-Base extraction of an Analgesic Tablet

The purpose of this experiment was to practice technique and acid-base extraction by separating and purifying the components of a common analgesic tablet. Analysis The purpose of this experiment was to separate and purify the components of an analgesic tablet. Furthermore, the separations allowed for practice of acid-base extractions. This experiment tested laboratory technique, considering that the pill used, Excedrin, contains only milligrams of the drugs to be separated: acetaminophen, caffeine, and aspirin (see Table A for acid/base comparison by […]

Sodium Borohydride Reduction of 2-methylcylohexanone

Purpose The object of this experiment was to reduce the ketone group of a cycloalkane into an alcohol group. This reduction forms cis and trans isomers and the experiment intended to determine which was more favorable. Analysis The object of this experiment was to reduce the ketone group of 2-methylcyclohexanone to form 2-methylcyclohexanol (see figure 1 below). Infrared spectroscopy, an important analytical technique, was introduced to examine the purity of the product. Infrared spectroscopy analyzes a chemical’s transmittance over a […]

Bromination of Cholesterol and Debromination: Purification of Cholesterol

Written by: Nicholas Connor The purpose of this experiment was to understand alkene-halide reactions by purifying commercial cholesterol. Analysis The purpose of this experiment was to remove the impurities present in commercial cholesterol; to yield pure 5-Cholesten-3B-ol. Bromination was the method chosen to remove traces of 3B-cholestanol, 7-cholesten-3b-ol, and 5,7-cholestadien-3B-ol that were assumed to be present in the sample used. The net reaction of bromination follows: To begin removing the impurities, the cholesterol sample (0.97 g) was dissolved in tert-butyl-methyl-ether […]