Simple and Fractional Distillation of Cyclohexane and Toluene
The purpose of this experiment was to become familiar with the processes of simple and fractional distillation. In this experiment a mixture of two volatile compounds, cyclohexane and toluene, were separated with the process of distillation. Distillation relies on each compound having distinct and separate boiling points. The pure products were analyzed with gas chromatography to determine the success of the distillation.
Distillation is the process of heating a liquid until it boils, then condensing and collecting the resulting hot vapors. Chemists have been applying the principles of distillation for thousands of years. Today, distillation is an extremely valuable tool in the modern organic chemistry laboratory, both for the identification and the purification of organic compounds. The boiling point of a compound is one of the physical properties used to identify it. Distillation is used to purify a compound by separating it from a non-volatile or less-volatile material. When different compounds in a mixture have different boiling points, they separate into individual components when the mixture is carefully distilled.
The boiling point is the temperature at which the vapor pressure of the liquid phase of a compound equals the external pressure acting on the surface of the liquid. The external pressure is usually the atmospheric pressure. Different compounds boil at different temperatures because each has a different, characteristic vapor pressure: compounds with higher vapor pressures will boil at lower temperatures.
Boiling points are usually measured by recording the boiling point (or boiling range) on a thermometer while performing a distillation. This method is used whenever there is enough of the compound to perform a distillation. The distillation method of boiling point determination measures the temperature of the vapors above the liquid. Since these vapors...