Fractional Distillation and Gas Chromatography (Investigative) Kevin Dural The University of Texas at Austin Fractional Distillation and Gas Chromatography (Investigative) Data and Results All data and results are attached. Included are carbon copies of written data and printed gas chromatography data. Discussion The purpose of this experiment was to identify two unknowns and their ratios in a given mixture. The identities of the unknowns were two of either acetone, methanol, hexane, cyclohexane, heptane, toluene, or ethyl benzene. Distillation Distillation is used to remove impurities from a mixture – one component of which must be a liquid.
The temperature at which wax is first precipitated from the solution can be measured by the cloud point test. The pour point of oil is an indication of the lowest temperature at which the fuel can be pumped. Pour points often occurs 8F to 10F below the cloud point. Pour point increases with molecular weight, but they are strongly influenced by molecular shape. Procedure The sample was brought to a temperature at least 14°C above the expected cloud point.
In a simple distillation, the solution is brought to a boil and the vapours rise into a stillhead that directs them into a condenser. The vapour is condensed to the liquid phase and collected. This method works well for solutions that are composed of liquids with vastly different boiling points. However, if the liquids are similar in boiling points, fractional distillation is the preferred method of separation. In this technique, vapours are forced to pass through a fractional distillation column before reaching the stillhead.
Thanks to the boiling chips, the heat is evenly distributed within the flask, which permits a more controlled boil and eliminates the possibility of the liquid in the flask bumping into the condenser. The tedious distillation process is rather simple: the beverage evaporates in the distillation flask and, having no where else to go, enters the condensing tube, where it cools down and is converted back into liquid form. From there on, this liquid flows into the final container, a graduated cylinder [preferably in an ice bath]. The extracted distillate is otherwise known as ethanol, a clear, colorless, flammable liquid, produced through the process of glucose fermentation and frequently used as an intoxicating agent in liquors. In relation to a previous experiment in which the students determined the boiling points of two liquids, it was deduced that the boiling point of [propyl and methyl] alcohol was estimated to be around 80oC.
This curve does not match exactly the figure 6 on the lab manual. It is steeper than the simple distillation but not as sharp as the fractional distillation. Some errors in the experiment that led to these results were the heat applied to the mixture was not constant. It had to be fluctuated as initially, the rate was too high but when the heat was set to low there was barely any distillate in the receiver. Throughout the experiment, there was a struggle to keep the heat stable which led to inaccurate data.
Again we will use ρ=m/V in order to calculate the density of water. Experimental technique The first part of experiment is done in following steps: The second part of experiment is done in following steps: Results The density of water by using hydrometer: 1. 26.5 °C room temperature 2. 37.8 °C and 36.3 °C 30-40 °C 3. 41.7 °C and 40.2 ° C 40-50 °C 4.
Some of the factors are thermometer was calibrated to determine its precision. The actual melting points of water, phenylacetic acid, o-anisic acid, and benzilic acid to their observed melting points were determined by calibrated thermometer. Then the solubility tests were run in order to determine the appropriate solvent for the unknown solute (Table 1). After determination of a solute, a vacuum filtration technique was used to determine the pure form of compound. The melting point of the purified sample was determined and compared to the melting points of other known compounds.
Abstract The experiment was performed in order to compare the effectiveness of Simple and Fractional distillation in separation of solid impurities from liquid and liquids with difference in boiling point higher than 25⁰C. The distillation curves of both processes were graphed on each case and compared. The main source of possible error was discussed and the way to improve the experimental procedure was proposed. It was concluded that the Fractional distillation is more efficient procedure than Simple distillation in liquid separation. However, in case of separation of solid impurities from liquid or liquids with high difference in boiling points Simple distillation can be preferred.
The mixture of the oil and excess solvent was poured into a weighed round bottomed flask. The flask was fitted to the rotary evaporator and immersed in the heating medium until all the mixture was totally immersed. The temperature of the rotary evaporator was set slightly above the boiling point of the solvent. Then, the mixture was rotated slowly to prevent the mixture to evaporate out from the instrument. The vacuum pump was switched on to suck the evaporated volatile solvent.
We then take the sample out of the water and immediately wipe it thoroughly, after which it is placed in the calorimeter with tap water. We then stir the water around the sample in order to quickly attain thermal equilibrium. We record the final temperature once thermal equilibrium of water and the sample together is attained. We then repeat the said steps but then with the other