Kristel Joy M. Tan, Joshua Michael L. Torres, Pauleen Anne S. Vanadero, Paulene Arielle P. Ynzon and Rachel Pauline E. Zaballero Group 10, 2D Medical Technology, Faculty of Pharmacy, University of Santo Tomas
Distillation is the most common technique, it is a process wherein the liquid is separated from the solution by boiling the liquid solution and condensing the vapor in order to get the distillate. There are four kind of distillation: simple distillation, fractional distillation, vacuum distillation and steam distillation. Simple distillation is the process wherein the pure liquid is separated from the solution with different boiling points. 20mL of Vokda (Antonov) was placed in a pear-shaped distilling flask for heating until the solution boils, the maximum boiling point of it was 100°C. The pure liquid turned into a vapor and left the distilling flask. The vapor then was condensed in the condenser and turned into a distillate. The distillate was collected in a calibrated and numbered test tubes and the temperature was recorded as well. The group was able to acquire 22.50% of ethanol in the compound and got 22.50% of error in the simple distillation experiment.
Distillation is a process of separating and purifying liquid mixtures, where one substance is separated from another by condensation and evaporation. There are four methods of distillation: simple distillation, fractional distillation, vacuum distillation and steam distillation.
Simple distillation is the process wherein the pure liquid is separated from the solution with different boiling points. It is by boiling the liquid solution in a pear-shaped distilling flask and for it to evaporate and pass through the condenser for it to become a distillate.
Fractional distillation is almost the same as the simple distillation, the only difference is that in a fractional distillation, fractionating column is used which is attached at the top end of the pear-shaped flask and it is connected to the condenser as well.
Vacuum distillation is a process used to reduce the pressure to a lower boiling point. In a vacuum distillation, the solvent’s boiling point should be over 300°F or 150°C. This distillation method is used to recuperate the solvent’s higher boiling point. (Finish Thompson Inc.)
In a steam distillation process, the main objective is to separate the two components in a temperature that is lower than their decomposition point. Steam distillation is process of separation to separate natural aromatic compounds. In order for the boiling point of the mixture to subside, steam or water is to be put in the distillation apparatus. (Helmensenstein, 2013)
The group performed simple distillation in order to separate the alcohol content of vodka from the solution. The objective of this experiment was to separate the alcohol component in the Vodka (Antonov) and to compute for its percentage of ethanol.
MATERIALS AND METHODS
The materials the group used in this experiment are Vodka (Antonov), boiling stones, alcohol lamp and the quick-fit apparatus which consist of the following: iron stand, iron ring and iron clamp for support, pear-shaped distilling flask, distillation head, thermometer, thermometer adapter, condenser, vacuum adapter and test tubes.
The very first step in this experiment was to make the simple distillation set-up. The iron clamp attached to the iron stand became the supporting apparatus for the distillation head, which was connected to the pear-shaped flask and another iron clamp attached to the iron stand was supporting the condenser, which a part of the distillation head and the vacuum adapter was connected to. The thermometer was attached at the top end of the distillation head together with the thermometer adapter to see the regulation of the temperature. The group prepared 20 test tubes and it was calibrated to 5mL, marked the lower meniscus of it using a marker and labeled it accordingly. The group placed at least three boiling chips/stones into the pear-shaped distilling flask and added 20mL of Vodka (Antonov) inside the said flask. Boiling chips were placed inside the pear-shaped distilling flask in order to avoid bumping of molecules and prevention of having a contamination.
Alcohol lamp was used as the heat source. The group rotated it under the pear-shaped distilling flask in order for the liquid mixture to boil. Each of the calibrated and numbered test tubes, the group collected 0.5mL of distillate and while collecting the distillate, the temperature at which the distillate was collected was recorded. This was applied for all test tubes that was filled with 0.5mL distillate. At 99°C, the group stopped collecting the distillate. For the first three to five drops of the distillate in the first test tube, it was collected and placed in a watch glass. The same procedure goes with the last three to five drops of the distillate in the last test tube. Flame test was applied to these collected distillate in order to check the presence of ethanol.
Figure 1. Simple Distillation Set Up
RESULTS AND DISCUSSION
In a fractional distillation, fractionating column is used unlike in a simple distillation. The fractionating column is attached to the pear-shaped flask. The vapor from the boiling compound will rise up going to the fractionating column and will be condensed at the column’s packing, after it will revaporize and condense again and that process is called rectification that helps to purify the substance more. This is the reason why fractional distillation is more efficient than simple distillation. (Yoder, 2013)
Table 1. Results of Simple Distillation
Test Tube| Volume| Temperature|
0| 0 mL| 30°C|
1| 0.5 mL| 80°C|
2| 1.0 mL| 80°C|
3| 1.5 mL| 80°C|
4| 2.0 mL| 80°C|
5| 2.5 mL| 80°C|
6| 3.0 mL| 80°C|
7| 3.5 mL| 80°C|
8| 4.0 mL| 80°C|
9| 4.5 mL| 80°C|
10| 5.0 mL| 80°C|
11| 5.5 mL| 82°C|
12| 6.0 mL| 84°C|
13| 6.5 mL| 85°C|
14| 7.0 mL| 86°C|
15| 7.5 mL| 88°C|
16| 8.0 mL| 90°C|
17| 8.5 mL| 93°C|
18| 9.0 mL| 96°C|
19| 9.5 mL| 98°C|
20| 10.0 mL| 99°C|
The data used in Table 1 was used in the graph below in order to see the relationship of the volume of the distillate (mL) and its temperature (°C).
Graph 1. Temperature as a function of Volume
As Graph 1 was shown, from the temperature of 30°C (room temperature) it quickly rose to 80°C and stayed constant from 0.5mL to 5.0mL which indicates the presence of alcohol of the vodka used.
The percentage of ethanol and percentage loss were computed using following formulas: For the percentage of ethanol:
% Ethanol = (Volume of ethanol distillate / Volume of Vodka Sample) x 100 % Ethanol = (4.5 mL / 20 mL) x 100 = 22.50% ethanol
The group was able to obtain 22.50% ethanol from the Vodka sample. For the percentage loss:
% Loss = [Volume of Vodka Sample – (Volume of ethanol distillate +
remaining Vodka Sample)] / Volume of Vodka Sample x 100% % Loss = [20 mL – (4.5 mL + 11 mL)] / 20 mL x 100% = 22.50% % Loss = 22.50%
The group was able to acquire 22.50% of error and it means that while gathering the data, there were errors made and the possible errors that were made during the experiment may be the following: inaccurate calibration of test tubes, or inaccurate drops of distillate per test tube or inaccurate recording of the temperature.
In conclusion, the objective of this experiment of separating the alcohol component in the Vodka (Antonov) was successful but the group must gather more precise data in the succeeding experiments.