Distillation is a technique widely used in organic chemistry for separating compounds based on differences in their boiling points. The experiment is divided into two parts: simple distillation, an easy set-up where a solution or a mixture of substances with different volatility is separated through exposure heat; and fractional distillation, which under goes a series of evaporation and condensation process to purify more complex mixtures. Raoult and Dalton Law are the two principles involving with this experiment. The former states that the vapor pressure of a solvent above a solution is equal to the vapor pressure of the pure solvent at the same temperature scaled by the ...view middle of the document...
2. Preparation of the equipment needed
The experimenters prepared and numbered test tubes with a calibration down to 0.5 mL mark.
3. Application of vodka sample
Then, they placed 3 pieces of boiling stones into a quick-fit distilling flask and included a 30 mL of vodka sample.
4. Heating the flask
With the use of an alcohol lamp, they heated the flask in a rotating fashion until the vodka started to boil. After which, the temperature was recorded at the first drop of the distillate.
5. Recording of the temperatures
After the temperature reached about 180°, the temperatures of each test tubes with the distillates were noted after a 0.5 mL mark.
6. Test using flame
The first test tube with 3-5 drops of the distillate placed on a watch glass was subjected to a flammability test.
7. Repeat the process
Repeat the steps on the distillate from the last test tube.
RESULTS AND DISCUSSION
The figure below shows the relationship of temperature (°C) to the volume of vapor collected from the sample. The highlighted part indicates where the concentration of alcohol is strongest.
Figure 1.1 Relationship of Temperature (°C) vs. volume (mL)
An increase in temperature for 0.50 ml of collected vapor describes the table below. When the temperature becomes constant and eminent a constant slope in the graph, it confirms the presence of ethanol in the sample wherein it is most concentrated. There is a presence of alcohol when it produces a flame during flammability test. The alcohol beverage in the experiment shows a blue flame. When there is a presence of flame, blue color is produced. On the other hand, if there is no flame produced, ethanol is not present in the sample test tube.
Test Tube | Volume (ml) | Temperature (°C) |
1 | 0.5 ml | 76 °C |
2 | 1.0 ml | 76 °C |
3 | 1.5 ml | 77 °C |
4 | 2.0 ml | 78 °C |
5 | 2.5 ml | 78 °C |
6 | 3.0 ml | 78 °C |
7 | 3.5 ml | 78 °C |
8 | 4.0 ml | 78 °C |
9 | 4.5 ml | 78 °C |
10 | 5.0 ml | 78 °C |
11 | 5.5 ml | 78 °C |
12 | 6.0 ml | 78 °C |
13 | 6.5 ml | 79 °C |
14 | 7.0 ml | 79 °C |
15 | 7.5 ml | 79 °C |
16 | 8.0 ml | 80 °C |
17 | 8.5 ml | 80 °C |
18 | 9.0 ml | 81 °C |
19 | 9.5 ml | 82 °C |