Lab 2, Distillation - Lab report PDF

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Mohammed Abdelrehem March 4, 2019 CHEM 121 Distillation Lab Report Purpose: The purpose of this lab was to become familiar with both types of distillation that separates two compounds from one another. Distillation is the heating of a liquid to induce a phase change to the gaseous state, and then condensing the vapor in a separate container in a purer state. This was done by fist setting up the simple distillation and observing the chemicals separate, then setting up the fractional distillation, a longer process to separate compounds especially when boiling points are close. This was also closely observed including timing, temperature, and volume. Chemicals & Equipment: 

Distillation apparatus

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Boiling Chips

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10 mL graduated cylinder

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Hexane, toluene, 20 mL 1:1 mixture of each

Summary Procedure: Add 20 mL of 1:1 mix of hexanes and toluene to a flask and add a few boiling chips which will allow it to boil more smoothly. Assemble the rest of the distillation apparatus leaving a 10 mL graduated cylinder at the end to collect the final product. Use plastic clips to keep everything together. After everything has been set up use the heating mantle to adjust the amount of heat being added to the process. When the condensation reaches the tip of the monitor start

observing and recording the temperature occasionally. When the liquid start pouring into the graduated cylinder record the temperature and the amount collected for every 0.5 mL When 5 mL is reached increase the heat and wait until there is about 1 mL left in the flask and stop the process. Move onto the fractional distillation by just simply adding the fractional column. This will take longer, but still has the same steps. When it is almost distilled the process is paused due to the higher boiling point toluene which will work its way up. Heat may be added as much as necessary. Record all observation and amount collected, time, and temperature. Data/Results:

Discussion: After concluding the experiment, we can determine many things. First, we can determine the main difference between simple and fractional distillation. Though it took longer and seemed to be more accurate, it actually isn’t. As learned before doing the lab fractional distillation is usually taken place when we are separating compounds with smaller boiling point differences. In this case with almost over 100-degree Celsius difference in hexane and toluene’s boiling point simple distillation would be more affective. We also understand that fractional distillation is a repetition of simple distillation multiple times to separate the compounds completely. We can also see a difference in temperature between the two types of distillations, we see that simple distillation goes up in temperature gradually and steadily, while fractional distillation starts off at a low temperature and stays that way until it goes up drastically and continues going up. This happens due to the fact that in fractional distillation it takes quite a while for the condensation to reach the thermometer. In both graphs we can say that as time passes and as the volume of distillate increases so does the temperature. During the experiment, our first trial we used an excess amount of heat dripping the distillate too fast not giving us enough time to record our data. From

the lab we can also learn that vacuum was necessary in this experiment because it allowed lower the pressure of the system which makes it easier to vaporize...