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Fractional Distillation & Gas Chromatography

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Fractional Distillation & Gas Chromatography
Fractional Distillation & Gas Chromatography
Exp. 1

Pre-Lab: 1) When two substances whose molecules are very similar from a liquid solution, the vapor pressure of the mixture related to vapor pressure of the pure substance. Also it could be defined as a two liquid are ideal solution when they don’t react with each other and they make no association. 2) Are a mixture of at least two different liquid, and known also as a mixture of two or more liquid in such away that its component cannot be change by simple distillation.
Objective
In this experiment we aim to demonstrate that we can separate two volatile compounds from a mixture due to the different chemical properties of each compound. We will accomplish this by a separation procedure known as distillation, which relies on each compound having a distinct and separate boiling point. Our pure products will be analyzed with gas chromatography to determine the success of the distillation.
Data and Results
The distillation curves for our simple and fractional distillation (See page 3) clearly demonstrate that fractional distillation separates the two compounds more completely. The boiling point (bp) of our unknown compounds was taken from the flat regions of the fractional distillation curve. Our unknown mixture contained hexane (bp 69 ºC) and toluene (bp 110.6 ºC).
Analysis via gas chromatography allowed us to determine the relative percentage of hexane and toluene at fractions near the beginning and end of our distillations. Relative percentages have been recorded in the table below, and our calculations are shown on page 5.

Conclusion
This week we utilized two methods of distillation (simple and fractional) to separate a mixture of two volatile compounds. We found that while the simple distillation separated the majority of the two compounds near the beginning and the end of the distilling process, fractional distillation produced much more pure fractions. In simple distillation the

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