Experiment 3B Fractional Semi-microscale Distillation Separation of Hexane and Toluene
1026 WordsDec 3, 20135 Pages
Chem 2203 Sec 026
Experiment 3B: Fractional Semi-microscale Distillation Separation of Hexane and Toluene.
Objective: The main goal of this lab is to learn how separation of binary liquid mixtures is performed. Especially when the two liquids have boiling points varying by about 30° C. Hexane can be separated from toluene in this experiment because of the difference in their boiling points. Since toluene has a higher boiling point, it will left at the bottom while the hexane starts to boil out and collect in the Hickman still. GC measurements help us in determining how accurate our data is by making a graph of the amount of hexane and toluene in each fraction. Also this lab gives experience with semi-micro…show more content…
For instance hexanes’ boiling occurs at a lower heat setting so that is why in the first fraction we can view a greater peak of hexanes than toluene. In the third fraction we notice that toluene is found in higher abundances there. This helps when trying to distill out or separate the two compounds.
b. Are the GC data consistent with your expectations?
The GC data is what is expected, however there were some difference noticed with it than expected. For instance, the first fraction came out with more toluene that was originally expected and the graph showed this. Small unexpected material like this was the only thing not expected with the GC data.
4. Most of you did not have enough time to complete the redistillations of Fraction 1 and Fraction 3, but you are still equipped to anticipate the results.
a. For the redistillation of Fraction 1, predict how the gas chromatogram for the initial fraction would have differed from the gas chromatogram of Fraction 1 from Distillation 1.
The peaks would be more pronounced and there would be a greater variance in the size of the peaks. Peak 1 would be much higher and steeper and peak 3 or the toluene peak would be found much smaller.
b. Similarly, for the redistillation of Fraction 3, predict how the gas chromatogram for the final fraction would have differed from the gas chromatogram of Fraction 3 from Distillation 1.
b.i. The difference between