Cyclohexane and Toluene
Lab partner:
Chemistry 211
2/08/12
Goal: The purpose of doing this experiment is to separate a sample of cyclohexane and toluene using simple miniscale distillation. The objectives will be to record boiling range and volumes (mL) of distillates that are acquired during the distillation process. It is expected that cyclohexane boils and distils before toluene. By gathering these measurements will allow us to determine refractive index of fractions collected. An Abbe refractometer will be used to accomplish this.
Data:
Table 1: Distillation Fraction #1: | Fraction #2: | Fraction #3: | Volume (mL) | Temperature (ºC) | Volume (mL) | Temperature (ºC) | Volume (mL) | Temperature (ºC) | 1 mL | 82ºC | 2 mL | 84 ºC | 2 mL | 91 ºC | 2 mL | 83ºC | 4 mL | 86 ºC | 4 mL | 92 ºC | | | 6 mL | 88 ºC | 6 mL | 93 ºC | | | 8 mL | 90 ºC | 8 mL | 96 ºC |
The table above shows three different fractions that my group and I gathered during our distillation process. It shows volume at a certain temperature in which it distilled. Fraction #1 shows the first 2mL that was acquired. These couple of mL were thrown out due to a possibility of impurities present. Fraction #2 shows 8 mL of what most likely should be cyclohexane. Fraction #3 is the remaining, toluene, that was last to distill.
Table 2: Refractive Index | Fraction 2: | Fraction 3: | Fractional Distillate Observed (nD20) | 1.4352 | 1.4798 | Refractive Index | 1.584 | 1.586 |
Instructor provided students with fractional distillate. Refractive Index was determined with usage of a Abbe refractometer. Samples of each fraction were placed in apparatus to acquire results.
Discussion:
Before my group and I started our experiment, it was expected that cyclohexane would boil and distil before toluene. The reason behind this is cyclohexane’s lower boiling point in comparison with toluene (81ºC vs.110 ºC). Our distillation process proves