Simple Distillation Of Cyclohexane

Mona Vaidya
02/04/2014
CHE 317
Laboratory Experiment #1: Simple Distillation of Two Volatile Liquids Containing Non-Volatile Impurities

Introduction: Simple distillation is a commonly used method to separate and purify the mixtures of organic liquids into their original components. Mixtures of two miscible liquids with two different boiling points were separated. Therefore, it can be said that the two organic compounds are separated by exploiting the different boiling temperatures of the liquids. Both vaporization and condensation were used in this experiment. The two organic compounds used in this experiment were ethyl benzene and cyclohexane, which have the boiling point of 136°C and 80.74°C, respectively. This experiment resulted
Since cyclohexane has a lower boiling point, it will evaporate and then vaporize around 80°C (cyclohexane boiling point); this organic liquid will be the first to be collected because it is less volatile in comparison to ethyl benzene. The temperature will continuously increase until all of the cyclohexane has been collected. After all of it has been collected, the temperature will either plateau or plummet down. Once this is observed, the heat is increased because it is more volatile; the boiling point of ethyl benzene can be observed and it will be collected in the graduated cylinder. The boiling point for ethyl benzene is 136°C. Once enough volume is collected, the experiment is
Since simple distillation is a physical process, it separated the two chemicals from the mixture based on how easily they vaporize. As the mixture was heated, the temperature rose until it reached the temperature of the lowest boiling substance in the mixture which was cyclohexane. The temperature at which the first drop was collected was 79.5oC and the distillation of cyclohexane was stopped when the still-head temperature was 94.5oC . Therefore, the boiling range of cyclohexane in this experiment was 79.5oC- 94.5oC.The resultant hot vapor passed through into the condenser and was converted into liquid, which was then collected into a graduated cylinder. During this time, the ethyl benzene remained in its original phase. Since cyclohexane had a lower boiling point, it is considered to be more volatile in comparison to ethyl benzene. After a plateau in temperature was observed, the temperature was increased in order for ethyl benzene to reach its boiling point. The temperature at which ethyl benzene was collected was 127oC and the distillation of ethyl benzene was stopped when the still-head temperature was 138.5oC. The boiling range for ethyl benzene was observed to be in between 127oC-138.5oC. The liquids were collected in increments of 4mL. The first 28mL collected were of cyclohexane and the last 16 mL collected were of ethyl benzene,