Patrick LePochat (U93484271)
Lab Partners: Jonathan Gomogda, Thomas Cella
Fractional Distillation Credit to: Group 11
TA: Matt Knestrick
Simple and Fractional Distillation of a Binary Mixture
Introduction Distillation is the process by which a solution containing two or more compounds with varying volatility are heated until the lowest of the compounds boiling points occurs, vaporizing it into the distillation head (containing a thermometer) followed by condensing it (with running water through a tube from bottom to top) until it becomes a liquid where it can again be captured in a receiving flask.1 This process works best and gives purest results when one of the compounds is volatile (easily vaporized) and the other is either non-volatile or volatile with a different boiling point.1 The means with which this process works is by giving sufficient energy to the compound, which in this case is the lighter compound, with the lowest boiling point such that it will vaporize while the (heavier) compound with the higher boiling point remains in the solution with insufficient vaporization energy. Boiling point of a liquid can be impacted in many cases by intermolecular forces such as hydrogen bonding or dipole-dipole interactions, but in this instance cyclohexane (bp: 81°C) and toluene (bp: 111°C) only experience dispersion forces with no distinct differences other than their molecular weights.2 The boiling point is signified by the vapor pressure equaling the
Whereas for simple distillation, the compounds need to be around 80C apart in order for proper separation to occur. Thus, cyclohexane and toluene were not able to be properly separated since the boiling point for cyclohexane was 80.74C while the boiling point of toluene was 110.6C—there two boiling points are fairly close to one another. Thus, the mole fraction for cyclohexane and toluene were fairly low when compared to cyclohexane and
We used TLC analysis to identify each product obtained from the dihydroxylation reactions by spotting a TLC plate with the product of our reaction, a solution of cis-cyclohexane, trans-cyclohexane, and a 50:50 mixture of the two. We then placed the plate in a beaker with ethyl acetate saturating the atmosphere to allow the TLC plate to develop. Finally, we compared Rf values of the components of the mobile phase, after the phase was completed. 100% ethyl acetate was used instead of 100% Hexane or a mixture of Ethyl Acetate, because ethyl acetate has high polarity and can separate the components of a mixture to elution, unlike hexane, which is non-polar, and therefore unable to separate the components of the mixture. A 50:50 mixture of both would not work, because the polar and non-polar compounds would neutralize the mixture, and thereby not separate the components of the mixture.
Method: Distillation is based on the fact that the matter can exist in three phases - - solid, liquid and gas. As the temperature of a pure substance is increased, it passes through these phases, making a transition at a specific temperature from solid to liquid (melting point--mp) and then at a higher temperature from liquid to gas (boiling point--bp). Distillation involves evaporating a liquid into a gas phase, then condensing the gas back into a liquid and collecting the liquid in a clean receiver. Substances that have a higher boiling point than the desired material will not distill at the
Objective: The main goal of this lab is to learn how separation of binary liquid mixtures is performed. Especially when the two liquids have boiling points varying by about 30° C. Hexane can be separated from toluene in this experiment because of the difference in their boiling points. Since toluene has a higher boiling point, it will left at the bottom while the hexane starts to boil out and collect in the Hickman still. GC measurements help us in determining how accurate our data is by making a graph of the amount of hexane and toluene in each fraction. Also this lab gives experience with semi-micro
Simple distillation is more effective when the two components of a mixture have a difference in boiling point that is greater than 50°C. This large difference makes the need for theoretical plates non-existent since there is no need for multiple distillations per fraction. We can collect all necessary data from a simple distillation fraction using a gas chromatograph. The gas chromatograph vaporizes the injected sample and it begins to undergo partitioning. It is pushed into a small heated column that is coated in the liquid form of the sample. The longer the substance stays inside the column before passing over the heated wire, the longer the retention time is. The retention time is utilized to identify the substance, while the number of peaks shows how many substances are present, and the size of the peaks show how much percentage each substance occupies in a sample. The intrinsic properties of isopropyl acetate and toluene allow analysis of the provided data to become quite simple. Isopropyl acetate has a lower boiling point because it has a relatively low dipole moment and only one double bond. Thus, the intermolecular forces are relatively low in isopropyl acetate leading to a low boiling point. Toluene has a higher boiling point because the methyl group, attached to the benzene
Answer: Distillation is a method for separating a liquid from a solid or from another liquid in which the liquid is boiled off and then recondensed (Yee, n.d., Distilliation). It works because the substance you are looking to distill is boiled off recondensed and separated. It can be used to purify liquids from solids or from other liquids (Yee, n.d., Distillation).
Distillation of the first product began at 83 °C. A Pasteur pipette was used to remove 1-ml of the distillate into a vial. A second vial was filled with distillate until it reached 1-ml. As the second vial is being filled, observe the temperature and remove the apparatus from the heat source if there is an observed drop in temperature.
Simple distillation is a separation technique which can be used to separate and purify distillates from a liquid mixture which ideally contains one volatile and one non-volatile compound. If such ideal conditions are not possible—as is usually the case—then simple distillation can be applied as long as the liquid in question is composed of compounds that differ in volatility such that their boiling points differ by at least 40 to 50 degrees Celsius. Because
The purpose of this lab is to investigate the processes that can be used to separate two volatile liquids in a mixture based on their chemical properties. This is accomplished by fractional distillation, which separates chemicals in a mixture by differentiating them by their boiling points at atmospheric pressure. Specifically in this lab, fractional distillation is used to separate an unknown mixture into its respective pure components. The components are then identified using gas chromatography, which is also telling of the purity of the extracts and success of the procedure. The procedure of this experiment was specified in lecture by Dr. Fjetland and in Gibert and Martin’s student lab manual, Experimental Organic Chemistry: A Miniscale and Microscale Approach, 6th Edition.
Purpose: The purpose of the lab is to separate a mixture that is composed of three components by using fractional distillation, then analyze the results with gas chromatography to find the percent composition of each component within three samples.
1.) Briefly explain the concept of steam distillation. What is the difference between a simple distillation and a steam distillation? When a mixture of two immiscible liquids are distilled it is referred to as codistillation. This process is referred to as steam distillation when one of the liquids is water. This distillation is used to separate organic liquids from natural products and reaction mixtures in which the final product results in high boiling residues such as tars, inorganic salts, and other relatively involatile components. It is useful in isolating volatile oils from various parts of plants and not useful in the final purification of a
Distillation is a method of separating two volatile chemicals on the basis of their differing boiling points. During this lab, students were given 30 mL of an unknown solution containing two colorless chemicals. Because the chemicals may have had a relatively close boiling point, we had to employ a fractional distillation over a simple distillation. By adding a fractionating column between the boiling flask and the condenser, we were able to separate the liquids more efficiently due to the fact that more volatile liquids tend to push towards the top of the fractionating column, thereby leaving the liquid with the lower boiling point towards the bottom. After obtaining the distillates, we utilized a gas chromatograph in order to analyze the volatile substances in the gas phase and determine their composition percentage of the initial solution. Overall, through this lab we were able to enhance our knowledge on the practical utilization of chemical theories, and thus also demonstrated technical fluency involving the equipment.
The boiling range of the 1-pentyl ethanoate distillate was approximately between 149-151°C. This was indicated by the formation of the distillate and when the mixture of the purified 1-pentyl ethanoate started to vigorously
The purpose of this experiment was to separate a two component mixture using fractional distillation. Distillation is a process of vaporization than condensation of a substance, used primarily to separate substances from a mixture when there are different boiling points. Fractional distillation is when the mixture has multiple substances with similar boiling points, and a fractional column is used to create multiple vaporization/condensation cycles. Fractional distillation is important when two or more substances need to be separated, but they have similar boiling points.
The purpose of distillation is to purify a liquid. Distillations are use to purify contaminates out of water to obtain clean pure water, as well as, to separate mixtures of liquids into their individual components; e.g. methanol and water.