Experiment Design
You are asked to separate a mixture of toluene and cyclohexane. Assume that they do not form an azeotropic mixture. Design an experiment to do this. You must provide the following information.
a) A diagram of the equipment you will be.
b) What distillate fractions you will collect and the temperature range over which you estimate you will collect them.
c) A diagram graph you are expecting of the distillation temp. (y) versus the mass distilled (x), marking on this diagram the point at which you will be collecting each fraction.
d) how you will estimate the efficiency of your recovery of each component.
Thank you so much!
We can't draw diagrams (graphs or equipment set up) on this forum but here is a site that goes into this in detail. This is only one of many; if you don't find something here go to Google and type in "separation toluene and cyclohexane by distillation" without the quotation marks. There is a lot of info on this topic available on the internet.
http://vanilla47.com/PDFs/Toluene/Modular%20Labaratory%20Program%20In%20Chemistry%20Separating%20Cyclohexane%20and%20Toluene%20by%20Distillation.pdf
a) The equipment needed for this experiment is a distillation setup. This includes a distillation flask, a heating source (e.g., a hot plate or a mantle), a condenser, a collection vessel for the distillate, and a thermometer to measure the temperature during distillation.
b) During the distillation, you will collect two distillate fractions: one enriched in toluene and the other enriched in cyclohexane.
For the toluene-enriched fraction, you can collect it in the temperature range of 80-110 °C (as toluene has a boiling point of approximately 110 °C). This fraction will contain most of the toluene vapor, while the cyclohexane will have a lower concentration.
For the cyclohexane-enriched fraction, you can collect it in the temperature range of 70-80 °C (as cyclohexane has a boiling point of approximately 80 °C). This fraction will contain most of the cyclohexane vapor, while the toluene will have a lower concentration.
c) The expected graph of distillation temperature (y-axis) versus mass distilled (x-axis) will show a gradual increase in temperature with increasing mass distilled. When distilling the mixture, the temperature will initially be close to the boiling point of the component with the lower boiling point (cyclohexane). As the distillation progresses, the temperature will gradually increase to reach the boiling point of the component with the higher boiling point (toluene).
To mark the point at which each fraction is collected, you can add vertical lines on the graph at the respective boiling points of toluene and cyclohexane (110 °C and 80 °C).
d) To estimate the efficiency of recovery for each component, you can compare the amount collected in each distillate fraction with the theoretical amounts based on the composition of the original mixture.
For the toluene fraction, calculate the percentage recovered by dividing the mass of toluene collected by the expected mass based on the original composition. Multiply this value by 100 to express it as a percentage.
Similarly, for the cyclohexane fraction, calculate the percentage recovered by dividing the mass of cyclohexane collected by the expected mass based on the original composition. Multiply this value by 100 to express it as a percentage.
The efficiency of recovery for each component can then be compared to assess the effectiveness of the separation process.