Fractional Distillation Lab Report

Aim The purpose of this experiment was to use fractional distillation technique to separate cyclohexane and toluene.

Background Information Distillation is a technique which is used for separating two or more volatile products based on differences in their boiling points. Distillation can be used to separate a volatile solvent from a non-volatile product and separate a volatile product from non-volatile impurities. Simple distillation consists of a round-bottom flask, a distilling head, a condenser, an adapter and a receiver which are used to separate compounds where one is considerably more volatile than the other compound. This distillation is performed in one step. Furthermore, fractional distillation consists of a fractionating column in addition to the other apparatus. Fractional distillation is used when two compounds' boiling point differs by less than 40 C so that a better separation occurs. Figure 5 is a graph of

This curve does not match exactly the figure 6 on the lab manual. It is steeper than the simple distillation but not as sharp as the fractional distillation. Some errors in the experiment that led to these results were the heat applied to the mixture was not constant. It had to be fluctuated as initially, the rate was too high but when the heat was set to low there was barely any distillate in the receiver. Throughout the experiment, there was a struggle to keep the heat stable which led to inaccurate data. Additionally, while changing the receiver from cyclohexane to toluene there was a loss of distillate which also led to the errors observed in the data. Furthermore, if more data were collected for each compound it would be a better representation of the experiment's results. If these errors were avoided, then the experiment would be more efficient in distilling the two compounds from each other and the plateau would be as sharp as figure 6 in the lab