Fractional Distillation Lab Report x4n1m

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Ann Thi Le Organic Chemistry I (CHM2210L)y Fall 2015 Section: 80204

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Fractional Distillation of a mixture: Experiment 6 (pp 129-130) Technique 15 (pp 733-740,745-748) Ethanol-Water C2H6O

This experiment must be slowly processed with one drop per second, with t​he fractional distillation processing a yield of a total of 4 ml of ethanol in the collecting flask.​” Introduction:

Abstract: “Fractional Distillation is a separation of a mixture into its component parts or fractions, such as in separating chemical compounds by its boiling point. Fractional Distillation procedure should be insulated, as described. It is by heating them to a temperature at which one or more of the fractions of the compound will vaporize. There was the use of a heating mantle to boil the chemical to vaporization with Chemware PTFE Boiling stones (450 grams; D1069103). This distillation uses copper, 99+% turning in the Fractional Distillation Column, Code 317912500, CAS: 7440-50 8, EC-231-159-6, Lot-A0254804 (Product of the U.S.), it allows the 20-25% of H20/Ethanol C2H5O (EtOH lot info: Fischer Scientific, 95%; ACS Lot A 12476) to be subjected continuously to many vaporization-condensation cycles as the material moves up the column. (​H​2​0 of 100° and ethanol of 78.2° were being used.) The copper turning accepted the vaporization and the heat because it’s property of being a good conductor. The copper allowed fast cooling of the vapor so as a result cooling the vapor and reheating it for re-distillation. The copper was packed in the fractional distillation column but not too heavily packed that you can’t see right through it; but enough to see lights here and there. Fractional Distillation column have hot air rises from the boiling 50 mL round bottom flask and then as the particles hits the copper with water rushing inside the second column it turns into cooling vapor. The process continues until all the C6H2O is removed.

“This experiment is to learn about the separation of the substances and separation technique of the distille. Furthermore, this experiment analyze the composition of the distillate (the distilled liquid). Ethanol is commonly called ethyl alcohol is produced by the fermentation of sugars by yeasts (C2H6O). Ethanol have a boiling point of 173.​1°F (78.37 °C) with the density of .789 g/mL. The melting point is at -173. 2 °F (-114 °C). When the separation is completed with the solution being 20 mL distilled in the 50 mL round-bottom flask; the collected data must be weight in grams three times to get the average mass. The minimum or maximum points correspond to a constant-boiling mixture called an aerotrope. Azeotrope of ethanol-water have the composition (weight percentage) of 95.6% C2H6O, 4.4% H2O with the boiling point at 78.17 °C. Fractional distillation is better at separating liquids than simple distillation; even though simple distillation have an easier set-up, it requires the liquid to have more boiling point difference and give poorer separation among the liquids. So using fractional distillation; helps separate the complex mixtures of liquids with smaller boiling point separation. 1 (As shown in Figure 1) The average of the three measurement will help evaluate the graph to determine the percentage of ethanol; as well to determine the percentage of water remaining. Furthermore, all and all, this process is to test the solution L​aboratory Help! Distillation. (n.d.). Retrieved September 15, 2015. 1

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“ethanol-water” to a separation to gain closer access to pure ethanol solution. Materials and Methods: “An apparatus is being used from Figure 15.2 shown in the Tables and Figures below. 2 This figure shows the key aspects of material that was needed in this experiment, as well as what it suppose to look like when setting it up. There was the used of the 50 mL round-bottom flask as the distilling flask and the 25 mL round-bottom flask as the receiving flask; instead of using the graduated cylinder to depicts the mL. The data for the temperature versus drops of ethanol was not collected in this experiment. The use of copper turning (99+%; Lot- A 0254804) was put in the Fractional Distillation Column not being too packed. The boiling stone (Chemware PTFE) was then put in the 50 mL round-bottom flask. Boiling stone is added to the liquids to make them boil more calmly. There was an 25 mL unknown mixture as first (soon to be known as ethanol-water) in the same 50 mL flask with the heating mantle on at the voltage power of 80 J energy to gain the exact boiling point for the solution in separation. The room temperature was lead to be 25 °C. The distillation part was circulating the cooling H​2​O in the condenser to help the liquid to boil rapidly, having the time frame of ten to twenty minutes to proceed on having the distilled at one drop for every two seconds. The amount of heat the ethanol and the vaporization was slow at first but then grew to a steady rate because of the copper turning in the fractional distillation ​ avia, D., Lampman, G., Kriz, G., & P Engel, R. (2011). Fractional Distillation. In A small-scale approach to organic laboratory techniques(Third ed., pp. 731). Belmont, CA: Brooks/Cole. 2

that was in the column. After having at least three to five mL in the distilled bottle, I weighed each one mL three times with the pipette; Autoclavable Oxford Benchmate, to get the average mass of the liquid.” Results: “This experiment had the temperature of 72.9 °C; being close to the intended boiling point of ethanol-water at 78.17 °C. The time frame started was from 1:35 PM, with the boiling point started at 1:45 PM (68.9 °C) and ending at 3:30 PM. There was a constant drops of one drop for every two seconds with voltage power of 80 with the heating mantle. The heating mantle is a device a piece of laboratory equipment used to apply heat to containers or objects. ​No data of the temperature versus drops of ethanol was collected. The time frame would was from 1:45 PM to 1:35 PM to actually start boiling at the point with 68.9 °C.​ ​Using the “Figure 15.10 Ethanol-water minimum boiling point phase diagram” 3 can correspond to a constant-boiling mixtures called Azeotrope. Azeotrope at V​3​ has a composition of 96 % ethanol and 4 % of water with a boiling point of 78.1 °C; the boiling point is not much lower than pure ethanol at 78.3 °C- showing it is impossible to obtain pure ethanol from the distillation of any ethanol-water mixture that contain more than 4% of water. Nothing can be able to obtain that 100% ethanol. The first one mL weighted at 0.85 grams, the second one mL weighted at 0.87 grams and the last one mL weighted at 0.90 grams. Total with 2.62 and dividing by three to get the average ​Pavia, D., Lampman, G., Kriz, G., & Engel, R. (2011). Fractional Distillation. In A small-scale approach to organic laboratory techniques(Third ed., pp. 742). Belmont, CA: Brooks/Cole. 3

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mass of 0.87 grams. According to Table one (Down below) (Ethanol have a total of 46.07 g/mol) Using 96% ethanol: roughly 95%the calculating got multiplied by 0.785 g/mL to get a total of 74.575 g of ethanol. Pure water have a density of 0.99704 g/mL. Thus still working with the graph Figure 15.10: Ethanol from water separating point of condensation. But before all this, the calculation had received about 0.87 grams of ethanol out of the one mL (three times average.) ” Tables and Figures: Figure 1: ​Simple and Fractional Distillation curves: This depicts the temperature of simple distillation receiving at a much higher rate of temperature to get the volume of distilled that is needed to be collected; while fractional distillation starts at a slower rate of temperature but received greatly on the volume of distilled that is needed to be collected.

Figure 15.10 ​Ethanol-water minimum boiling point phase diagram: Slight incompatibility (repulsion) between the liquids being mixed. Table 1:

Figure: 15.2:​ This figure shows the Fractional distillation apparatus used in the experiment.

% E-OH by Weight

D (g/ml) @ 25 °C

75

0.051

80

0.839

85

0.827

90

0.800

95

0.785

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Discussion/Conclusion: “Theory of Distillation: ​is a process of separating the component substances from a liquid mixture by selective evaporation and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components of the mixture.There were two form of distillation, simple and for this experiment it was Fractional Distillation to require better result into separating the liquids. ​As the temperature increased and reached the lower boiling point of ethanol, the amount of ethanol in collecting flask started to increase. No data of the temperature versus drops of ethanol was collected. Usually it takes about ten to twenty minutes to get to the boiling point but there was an improper heating and and lack of temperature control. The start of the lab was at 1:35 PM with the voltage being on half of what it can take. It was set on 50 voltage of energy and during the time frame for the boiling to start wasn’t until 1:45 PM with 68.9​°C. Soon after when the process hits over twenty minutes not one drop was being form, realizing the voltage shouldn’t been on at least 80-90 voltage of power with the heating mantle. The distillate wasn’t supposed to be and was never should be gotten dried whatsoever or it will cause a breakage with the flask due to extreme heat and pressure inside the flask. Azeotrope a mixture of two different liquid; the used of minimum boiling point was greater in used than with Raoult's Law- forming a maximum boiling azeotrope point for this experiment. The distillation of the mixture going in the positive direction will result in distilled being closer in composition to the azeotrope than the starting mixture; to which the experiment was being done as. Usually, for example if the ethanol-water was 50%

each was being distilled once than it come out to be 80 % ethanol and 20% water. Distilling again and again can only reach to the ratio 95% and 4% of ethanol-water, respectively. ​The fractional distillation was all in all a good way of separating the two liquids. Going back to the definition of Raoult’s law is a law of thermodynamics; stating that the partial vapor pressure of each component of an ideal mixture of liquids is being equal to the vapor pressure of the pure component. After being multiplied by its mole fraction in the mixture. Even though the separation of the ethanol-water into two different liquids, it could not get to the pure ethanol needed even if the experiment was distilled over and over with the fractional distillation method. It had exceed the azeotropic ratio; for ethanol-water. The solution behind is richer than the last each time.” 7

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Reference List: 1.

L​aboratory Help! Distillation. (n.d.). Retrieved September 15, 2015. 2. ​Pavia, D., Lampman, G., Kriz, G., & Engel, R. (2011). Fractional Distillation. In A small-scale approach to organic laboratory techniques(Third ed., pp. 731). Belmont, CA: Brooks/Cole. 3. ​Pavia, D., Lampman, G., Kriz, G., & Engel, R. (2011). Fractional Distillation. In A small-scale approach to organic laboratory techniques(Third ed., pp. 742). Belmont, CA: Brooks/Cole.