The General Purpose

Introduction:

The General purpose of this experiment was to get comfortable with the technique of distillation as a means of purifying a substance. We did this by separating a mixture of A- Ethyl Acetate and N- Propyl Acetate. This entails vaporization, which is the process by which a liquid turned into a vapor. From this point it will go through condensation, which is the process by which the vapor is cooled and returned to its liquid state. From this point we will use Gas chromatographic technique to determine what the organic compounds are in the mixture. In this case it is A- Ethyl Acetate and N- Propyl Acetate. I predict that A- Ethyl will vaporize quicker and therefore will be found in higher quantities in earlier samples.

Experimental Section:

First the apparatus for vaporization and condensation was assembled (See Fig. 1). Then to a 25ml round bottom flask 8 Ml of both Ethyl Acetate and Propyl Acetate. Having labeled 3 conical vials the condenser was filled with water and the thermometer was adjusted. Then the flask was heated till it boiled. Once boiling the temperature was decreased to level 2. As the flask started boiling vapors were sent through the condenser and collected in the vials. My partner would take temperature readings every 1 mL collected. After 2 mL was collected in one vial it was replaced by another vial till 3 vials had been filled with 2 mL of the condensed vapors. There was about 2 ml left in the flask. After placing the vials and flask they were taken to the mini CG, where each sample was run through the program under parameters of start temperature 60 degrees Celsius, hold temperature 1 minute, Ramp rate 5 degrees/min, final Temperature 70 degrees Celsius, hold time 1 minute, total length 4 minutes and a pressure of 10.0 kPa. Before use of each sample the syringe was washed out with approximately 1/3 of the sample being tested. 0.1uL of sample was syringed, then injected, while simultaneously pressing collect, into the CG.

Discussion:

Our results showed that Ethyl Acetate had a lower boiling point and therefore evaporated first. This resulted in the Ethyl Acetate being present in higher quantities in the first vial. Once the Propyl Acetate had reached its boiling point, the Ethyl Acetate had begun to become less prevalent in the samples collected. This meant that Ethyl Acetate had a lower boiling