Simple And Fractional Distillation (2emt - Group 1, 2009)

Simple and Fractional Distillation Authors: ABESAMIS, Maria Feliza, ACOSTA, Marie Em Clarisse, AGUSTIN, Francheska, AQUITANIA, Mary Christelle, BAGSICAN, Marilu Jane Abstract Distillation is the extraction of volatile component of a mixture through a two way process, evaporation and condensation. Volatility is the tendency of a substance to vaporize easily. In distillation, when a substance is heated, i.e., ethanol and water, the more volatile substance vaporized first. The result is the separation of two or more substances. The experiment is divided into two parts, Simple and fractional distillation. Simple distillation is an easy set-up where a solution or a mixture of substances with different volatility is separated through exposure heat. Evaporation takes place, changing liquid to gas. Vapors form and pass through a condenser wherein it changes its form from gas to liquid. The collected vapor is the distillate of the experiment. Residue is the remains in the set-up that didn’t pass through the process of evaporation and condensation. On the other hand, fractional distillation under go series of evaporation and condensation process to purify more complex mixtures. It is more efficient in terms of decontamination or separation of substances. I.

Introduction Distillation is the process of purifying compounds by means of separating more volatile substance from non-volatile or less volatile substance. There are two principles that lie in the experiment, Raoult Law and Dalton Law. Raoult Law connotes that the vapor pressure of a solution equals the product of the vapor pressure of the pure solvent and the mole fraction of solvent. While Dalton Law, which is also known as law of partial pressure, implies that the pressure of a gas mixture is equal to the sum of the partial pressures of the gases composing it. In this experiment, the group should be able to attain the following objective: (1) to be able to separate the alcohol content of the alcoholic beverage, and (2) calculate for its percentage ethanol present. Lastly, (3) calculate for the efficiency of simple distillation and fractional distillation.

II.

Experimental The group required a micro distillation set-up to exhibit simple distillation and to examine the presence of ethanol in the alcoholic beverage. The set-up should be prepared and tightly secured. Clamps and iron stand held for the body of set-up, while aluminum foil covered the openings in the connection of each apparatus to prevent vapour loss in the actual experiment. Then, water inlet is turned on. Presence of boiling chips must be checked to avert bumping. When the set-up is fixed, through the use of alcohol lamp, the flask should be heated

moderately. The data was first recorded when the distillate first dropped. 5-ml distillate is collected for each test tube. Then, data is graphed and analyzed. Sequence of Simple Distillation Apparatus from the source of sample: Pear-shaped flask, Still head with thermometer, Leibig condenser, received adapter and the distillate receiver (test tube for this experiment) III.

Result and Discussion Table 1.0 Test Tube

Volume (ml)

1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

0.00 ml 0.50 ml 1.00 ml 1.50 ml 2.00 ml 2.50 ml 3.00 ml 3.50 ml 4.00 ml 4.50 ml 5.00 ml 5.50 ml 6.00 ml 6.50 ml 7.00 ml 7.50 ml 8.00 ml 8.50 ml 9.00 ml 9.50ml 10.00 ml

Temperature (°C)

25.0 70.0 72.0 73.0 73.0 73.0 75.0 76.0 78.0 79.0 80.0 82.0 84.0 86.0 86.5 88.0 90.0 92.0 94.0 96.0 96.0

°C °C °C °C °C °C °C °C °C °C °C °C °C °C °C °C °C °C °C °C °C

Flame Test

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Calculations:

The table shows an increase in temperature for 0.50 ml of collected vapour, When the temperature become constant and eminent a constant slope in the graph, it confirms the presence of ethanol in the sample wherein it is most concentrated. In the flame test, there is presence of alcohol when it produces a flame. The alcohol beverage in the experiment shows a blue flame. When there is no flame produced, ethanol is not present in the sample test tube. The graph shows the relationship of temperature to the volume of vapour collected from the sample. The highlighted part indicates where the concentration of alcohol is strongest. However, the calculations contradict the graph and errors might have been occurred during the experiment. Listed below are the following possible sources of error: 1. Parallex reading of temperature 2. 5ml calibration is not accurate and precise during the experiment 3. Few drops of distillate were missed while replacing new test tube for the distillate were not accounted 4. Accurate measurement of residue was skipped, resulting to 0% error 5. Distillate might have vaporize during the experiment before it was tested to flammability test 6. Not all test tubes were tested for flammability test 7. Flammability test and the graph did not match Due to these possible sources of errors, the results didn’t match.

IV.

Reference Books: Winkle, M. v. (1967). Chapter 9 – Mass Transfer Processes. In M. v. Cinkle, Distillation. New York: McGraw-Hill. Articles: (Heath, 2003) Heath, K. (2003). Laboratory Chemistry – Organic Techniques.Birmingham, United Kindom: Cirriculum Press. Websites: Answers.com. (n.d.) Retrieve July 11, 2009, from http://www.answers.com/topic/distillation Scribd.com. (n.d.) Retrieve July 11, 2009, from www.pdfcoke.com/doc/6602463/DKE202ch9