Distillation is a method of process of separating 1:1 mixture based on differences in their volatilities in a boiling liquid mixture. Distillation is done with the use of simple distillation apparatus shown in Figure 1. In this experiment, simple distillation process was used to determine the identities of the unknown compounds in the solution through the obtained boiling points. The list of probable unknown volatile components in the mixtures was provided along with the boiling points.
The simple distillation apparatus was constructed as instructed (Figure 1). A ~5mL vial was equipped with a stillhead, air and water-cooled condenser (thick column), claisen head, Hickman distillation head, thermometer, and thermometer adapter. The equipments were tightly clipped to prevent vapor from escaping apparatus. A thermometer was placed into stillhead with the support of thermometer adapter. The thermometer was supposed to be kept below the entrance of condenser to endure that the mercury bulb of thermometer is immersed thoroughly in vapors. The distillation was collected in the distillated head. A boiling stone was placed inside the vial, and 7.0 mL of unknown mixture was added. The thermowell was initially set to 75°C in order to heat the apparatus, and then lowered to ~40°C in order to maintain a 1 drop per five seconds rate. The temperature was recorded at every 0.5mL interval for liquid distilled. A small sample of distillate was collected in a 3mL conical vial when the temperature reached about ~81°C, and the second sample was collected when the temperature reached about ~111°C. Each sample was covered with a watch glass to minimize evaporation. The distillation was continued until there was a small amount of liquid remained in the distilling flask.
Figure 1 - Simple Distillation Apparatus using a Hickman still