Distillation
Lab # 3

Introduction:
Distillation is a process of vaporizing an impure liquid mixture in one container and collecting the condensed vapors in another container. The goal of distillation is to purify an impure sample, collect the pure sample and leave behind the impurities. When different compounds in a mixture have different boiling points, they separate into individual components when the mixture is distilled. There are several methods to conduct distillation, this lab applied the simple distillation method as described in the procedures referenced below, which means that the vaporization-condensation cycle is only completed one time. The process of distillation has been been used for many years, and will continue to be beneficial to purify compounds, as well as help recycle used solvents.
Procedure:

The lab procedures followed in the Simple Distillation Lab are from the following citation: Lecher, C. S. Simple Distillation: Purification and Reuse of Acetone, Chemistry, Marian College, 2007.

Verification of purity was determined from both the boiling point data collected and the infrared spectroscopy reading comparison between impure and pure acetone (see Data and Discussion below).

The boiling point of acetone used in this lab is obtained from Wikipedia online and the value is 56.538 degrees Celsius. This boiling point value will be applied to determine when distillation is nearing completion.
Diagram of Simple Distillation: Purification and Reuse of Acetone

Simple_distillation_apparatus.svg.png


1: Heat source
2: Still pot
3: Still head
4: Thermometer/Boiling point temperature
5: Condenser
6: Cooling water in
7: Cooling water out
8: Distillate/receiving flask
9: Vacuum/gas inlet
10: Still receiver
11: Heat control
12: Stirrer speed control
13: Stirrer/heat plate
14: Heating (Oil/sand) bath
15: Stirrer bar/anti-bumping granules
16: Cooling bath.


Data:
The weight of the beaker, beaker with impure/pure acetone was recorded before and after the distillation. The percent recovery of the Acetone is 87.17% after distillation.
Weight of Beaker (g)
Weight of Beaker with 40.0 ml
Impure Acetone (g)
Weight of 40.0 ml
Impure Acetone (g)
126.282
158.341
32.059
Weight of Beaker (g)
Weight of Beaker with 40.0 ml Pure Acetone (g)
Weight of 35.9 ml Pure Acetone (g)
126.400
154.346
27.946

The attached file includes the results of the simple distillation process with temperature measured every 30 seconds using a LabQuest temperature probe.
General Observations:
The temperature recorded when vaporation began (first drop) was 50.9 degrees C. The distillation process was complete at 14.0 minutes when the boiling flask appeared to be less than 5ml and the temperature was close to the boiling point and starting to rapidly decrease. The final volume of pure acetone remaining was close to the recommended volume to distill. what is the temperature at the time you stopped the distillation? the range is important as a way to assess purity.

The infrared spectroscopy results of the impure and pure acetone had a similar pattern, except the pure acetone had more small scale variability in the percent transmittance than the impure acetone.


Conclusion/Discussion:

The distillation process is used to purify compounds, such as acetone. This lab purified acetone by using the simple distillation process. Verification of purity of acetone was determined from analysis of the boiling point data and Infrared Spectroscopy results. During distillation the boiling point continued to rise consistently until it was within one degree celcius of the predicted boiliing point.

When boiling points continue to rise, this is an indicator of an impure compound or two compounds with similar boiling points. yes! The Infrared Spectroscopy results between the impure and pure acetone also supports that the distillation process was successful in purifying the acetone. where are they? can I see them? The Infrared Spectroscopy of the pure acetone showed more variability in the percent transmittance, in which demonstrates a change in the compound, thus assuming that it is more pure.

Have you discussed error anywhere? I'm not seeing where those comments are.

Post Lab:
Great American Paint Company Letter,

I am pleased to inform you that the simple distillation process to purify and reuse acetone was successful. This is a significant finding to both your company and the field of green chemistry. Your company will now be able to meet the environmental regulations for disposing paint contaminated acetone in a cost effective and environmental friendly way.

Our research was successful in distilling a small quantity of impure acetone into pure acetone ready to be used. This process can also be applied in larger quantities, such that your company is interested in recycling. Two methods were applied to ensure that the distilled product will meet your standards. We analyzed the boiling point temperatures during distillation to ensure that it was not consistent and it was within proximity to the boiling point temperature found in scientific literature. We also compared both the impure and distilled pure acetone with a spectrometer to determine if there was a difference between the two compounds. The data showed similar pattern, but the pure acetone had greater variability in the percent transmittance. The results of the boiling temperatures and the spectrometer provides us the data to support that our proposed method of recycling acetone will meet your companies needs. good.