Isopropyl Acetate And Toluene Lab Report

The purpose of this experiment was to separate a mixture of 1:1 isopropyl acetate and toluene by a method of fractional distillation by collecting the initial fractions from Hickman still and then redistilling them. Distillation process is a process in which a mixture composed of two liquid substances with different boiling points where the substance more volatile and with less boiling point distillate first. For this experiment, the isopropyl will evaporates first because it has the least boiling point (See Table #1). Gas chromatography is a technique for separating components of a mixture on the basis of the relative amount of each component distributed between a moving fluid stream. It is used to ensure that the desired product was obtained.

Using a calibrated Pasteur pipette, add a mixture of 3 mL 1:1 isopropyl acetate and toluene in the 5 mL conical vial. Then, add a spin vane and assemble the Hickman still heating the block. Wrap the connector and lower the portion of the Hickman still with aluminum foil to help contain the heat during the distillation process (also cover the top of Hickman still with aluminum foil. Place the thermometer in the heating block and then slowly stir the solution. Turn on the the hot plate and rise the temperature to 80-90 C. During the distillation the connector between flask and the Hickman still may loose, so, periodically, tight it. With a ben pipette, keep removing the distillate and placing it into a 0.5 dram via labeled “Fraction 1” until 1.2 mL of collection. After collecting 1.2mL, raise the the heating block temperature to about 105-115 C higher and the collect 0.6 mL of solution placing to a 0.5 dram via labeled “Fraction 2.” Now, remove the distillation apparatus and allow it to cool – there is 1.2 mL of liquid left in distillation conical via, place it to via labeled “Fraction 3.” Do the gas chromatography analysis and then dispose the fraction 2 and save fractions 1 and 3 for the next day experiment. Finally, Gas chromatography analysis is done using gas chromatography and LabQuest

The area under each peak allows the calculation of the quantity of the referred component. As expected from gas chromatography analysis, two peaks were seen demonstrating that here are two components in the mixture. Using the fraction #1, the first and biggest peak represents the isopropyl and the smallest represents toluene. This demonstrates that, as expected, the first collection was mainly composed by isopropyl because isopropyl has less boiling point (Table #1). On the contrary, for the last (third) collection GC analysis, the smallest peak represents isopropyl and the highest peak represents toluene. That happened because, since the majority of isopropyl was collected in the first run, the remaining quantity of isopropyl was small while the toluene quantity was higher (see figure 4 or table 3). The experimental calculations also prove that the quantity of isopropyl diminishes from the first fraction to the last (Table