Cyclohexane Distillation

Introduction The purpose of this lab was to compare simple distillations of two sets of liquids by graphing the boiling points. One set of simple distillation of two liquids were supposed to have a boiling point difference of bout 30C while the other set of simple distillations had a melting point difference of about 57C. Furthermore, by conducting this experiment, students would develop a better understand of distillation and gas chromatography. Furthermore, I hypothesized that cyclohexane and p-xylene distill better than cyclohexane and toluene since cyclohexane and p-xylene have a larger boiling point difference than cyclohexane and toluene. The boiling point of cyclohexane is 80.74C while the boiling point for p-xylene is 138.23C and the boiling point for toluene is 110.6, thus

One pair had a 50:50 mixture of cyclohexane: toluene while the other pair had a 50:50 mixture of cyclohexane: p-xylene. For both distillations, we were to collect the first milliliter and the last several drops in order to run a GC for each fraction. Furthermore, for both distillations, students obtained 30ml of their designated 50:50 mixture in a 50ml round bottom flask. By properly using the simple distillation apparatus, students were able to record the temperature of the distillate, we recorded the temperature for every 1ml. Once students collected the first 1ml, the 25ml of distillate and the remaining drops, we were able to determine the mole fraction of cyclohexane by using gas chromatography. With help from our TA, students were able to determine the areas under the peaks. Thus, in order to approximate the mole fraction of cyclohexane in each sample, we used the ratio of the area of cyclohexane peak to the sum if the cyclohexane and toluene or p-xylene peaks. Lastly, we graphed temperature as a function of volume for both distillations using the data collected from the