Experiment 2: Distillation and Purification of Liquids Angela Kaiser 100125701 ELL 308 September 19th, 2015 Introduction and Experimental: The purpose of this experiment was to determine the ratio of dichloromethane (DCM) to cyclohexane in a DCM/cyclohexane solution by carrying out a fractional distillation. The temperature and volume of distillate were measured periodically to determine the volume both components in the solution. The experiment was performed as written in “Experiment 2: Distillation and Purification of Liquids” from the Chemistry 2050 Lab Manual for Organic Chemistry Part 1, Fall 2015. Results and Observations: The solution of DCM and cyclohexane was clear and colourless. The following graph shows the recorded …show more content…
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. Fractional distillation columns may contain a metal sponge, or have glass projections inside the column in order to increase the amount of surface area that the vapour comes into contact with. This causes some of the vapour to condense while in the fractional distillation column. Consequently, it falls back into the liquid reservoir. However, when this liquid to the reservoir, it contains a higher ratio of the more volatile substance than it did originally. This is repeated numerous times in the fractional distillation column and each time the liquid vapourizes, the vapour increases in purity. Eventually, the vapour contains only the most volatile substance and it is condensed and …show more content…
There are multiple points both at 43°C and at 72°C which indicates that liquid was collected at these temperatures. Based on this information, it would appear that two different liquids were present in solution and that one liquid has a boiling point of approximately 43°C and that the other has a boiling point of approximately 72°C. The literature value boiling point for DCM in is reported to be about 40°C and it is about 80°C for cyclohexane. Based on the graph, DCM was collected from 4 ml to 22 ml, thus 18 ml of DCM was collected. Cyclohexane was collected from 26 ml to 35 ml, thus 9 ml of cyclohexane was collected. Therefore the observed ratio of DCM to cyclohexane was 18:9 or 2:1. Two sources of error may have affected the experiment. Firstly, the experiment required volumes of liquid to be recorded while the vapours were distilling. It was impossible to accurately measure the volume of liquid at any given moment, as the meniscus was moving side to side. Secondly, the distillation was ended while there was still liquid in to round bottom flask. The composition and volume of this liquid were unaccounted for in the calculated
Next, about 10 mL of both solutions, Red 40 and Blue 1, were added to a small beaker. The concentration of the stock solution were recorded, 52.1 ppm for Red 40 and 16.6 ppm for Blue 1. Then, using the volumetric pipette, 5 mL of each solution was transferred into a 10 mL volumetric flask, labelled either R1 or B1. Deionized water was added into the flask using a pipette until the solution level reached a line which indicated 10 mL. A cap for the flask was inserted and the flask was invented a few times to completely mix the solution. Then, the volumetric pipette was rinsed with fresh deionized water and
Characteristic property- Test 1- distillation Materials: Goggles, 250 ml beaker, 10 ml graduated
Graph: Temperature vs. Volume for Fractional Distillation Figure 3 This shows a direct correlation with a positive trend going upward with the temperature versus the volume. However, it should be noted that there is a drop at the 22nd ml with a discrepancy of 29 degree Celsius. However, it is very important to see if fractional distillation is more effective or simple distillation.
The experiment would have been unsuccessful if there was no ethanol obtained or if there was a very small yield of ethanol such as 5% or lower was obtained. A practical use for fractional distillation would be for purifying drinking water. Fractional distillation is the separation of a mixture into separate parts or fractions. Fractional distillation can separate the germs, bacteria and any impurities from the water. Once those are removed, the water will now be safe for human consumption.
The dehydration of 2-methylcyclohexanol takes place at the bottom of the Hickman still. As the Hickman still heats up within the sand bath, the products evaporate and travel higher up in the still where they condense into a liquid and fall within the collection ring, thus separating the product from the remaining water. Drierite (CaSO4) is also added as a drying agent to absorb any leftover water within the product. The purity of the product will then be analyzed with infrared spectroscopy, paying attention to OH peak if it is present. Chemical Reactions: Data and Observations: Material Volume Mol.
Fractional distillation was the better technique of separating toluene and cyclohexane than simple distillation because it had a greater percent toluene difference for fractions 2 and 4. Fraction 2 composed of mostly cyclohexane with a toluene percentage closer to 0% compared to simple distillation, while fraction 4 composed of mostly toluene with 100% toluene. The 100% toluene in fraction 4 indicated that the compound was purer in fractional distillation than in simple distillation, which had less percent
These small errors may be arised as a result of temperature. Because the accurate mesuring process took much time and during this time the temperature of water was decreasing. Among two methods the density bottle gives more accurate measurement of the volume, resulting in more accurate determination of density. One of disadvantages of hydrometer is that hydrometer has Operator dependent readings, therefore has limited accuracy. Morever, for measuring the density using hydrometer large sample volume is required.
Chapter five taught about the separation of mixtures through a number of different processes. These processes use differences in characteristic properties in the elements of the mixture. For example, fractional distillation uses boiling point to separate liquid mixtures. As the liquid boils, the vapor is redirected through a tube into a different test tube and then condenses. The tube is moved into a different test tube after the first fraction concludes boiling, and then the next fraction can be extracted, etc.
The fractions in the fractional distillation such as N-hexane, isohexane, methyl cyclopentane have normal boiling point close to cyclohexane which makes the recovery of cyclohexane uneconomic and difficult. 2. Quantity of cyclohexane recovered is not enough to meet the current demand since the cyclohexane content of naphtha is about 5%- 15% by weight .3 Selection of Pathway to Cyclohexane (2) Hydrogenation of Benzene: C6H6 +3H2 →
Again select the flask and select Distillation Head from the drop down menu. ➢ For the third time select the flask and choose Condenser from Distillation from the menu and for last time select the flask Distillation Take-off from the dropdown option. ➢ Select the 100 mL Graduated Cylinder from the Equipment option and put it underneath of distillation take-off.
1. 150 ml of boiled water was poured into each of the three beakers labeled A, B, C. 2. Five tea bags were soaked for the time given by the manufacturer (two minutes) , in beaker A (Control). The teabags were immediately removed after the time elapsed. 3.
Distillation is usually used to separate liquids from mixture, utilizing carefully monitored condensation. It’s effective to mixtures that consist of components that have differing boiling points; because of this, the component with the lower boiling point can be
What is fractional distillation? Fractional distillation is a method of separating miscible liquids using heat. This technique is used for the separation of liquids which dissolve in each other. Several simple distillations are completed during fractional distillation using only one apparatus.
This method which uses an internal standard and flame ionisation detector, is exact and more specific than methods usually used. The gas-liquid chromatography method determines ethanol clearly and separately from the other beverage components that would have interfered in other methods, without any distillation or need for a chemical reaction. Determination of ethanol is one of the most vital routine analysis in a current winery. This method provides frequent, rapid and accurate results are needed to regulate the quality of the wine from grape to bottle, as well as for state and federal government
As such, heating the seawater or brackish water until evaporation occurs leaves behind salt and the vapor is then condensed to provide fresh water. Several processes involved in the distillation process include Multi-stage flash distillation (MSF), Multiple-effect distillation (MED), cogeneration, vapor-compression evaporation (VC) and solar water desalination (Shatat and Riffat, 2012). Multi-stage Flash