3 mL of a 1:1 isopropyl acetate and toluene mixture along with a spin vane was added to a 5 mL conical vial using a calibrated Pasteur pipette. A Hickman still and heating block was assembled. The connector and lower portion of the Hickman still was wrapped with aluminum foil and the top of the still was loosely covered with foil. The thermometer was placed into the heating block and was moved into the Hickman still once the temperature of the heating block was near the listed temperature from the lab manual. The solution was stirred slowly while the hot plate was turned on. The temperature of the heating block was slowly (5°C/min) raised to 80-90°C. The connector between the flask and Hickman still was periodically tightened. Using a bent …show more content…
Fractional distillation was accomplished by using the knowledge of the boiling points of both isopropyl acetate and toluene and controlling the temperature of the apparatus so that one substance would boil but not the other. By doing this, isopropyl acetate was able to evaporate first because it has a lower boiling point than toluene. This is why Fraction 1 contained much more isopropyl acetate than it did toluene. By slowly raising the temperature of the apparatus to that of the boiling point of toluene, the distillate collected for Fraction 2 contained more toluene due to the majority of the isopropyl acetate having already evaporated. By using gas chromatography, the exact percentage of each substance in Fractions 1 and 2 were found. Fractional distillation was required to separate the liquids because isopropyl acetate and toluene have similar boiling points. It allows the liquid with the lower boiling point to evaporate and be collected and separated first. The liquid with the higher boiling point can then evaporate and be collected. The purpose of re-distillation is to removed most of the liquid with the lower boiling point and leaving a purer toluene in the vial. The working principle of gas chromatography is that once the solution is
14 mL of 9 M H2SO4 was added to the separatory funnel and the mixture was shaken. The layers were given a small amount of time to separate. The remaining n-butyl alcohol was extracted by the H2SO4 solution therefore, there was only one organic top layer. The lower aqueous layer was drained and discarded. 14 mL of H2O was added to the separatory funnel. A stopper was placed on the separatory funnel and it was shaken while being vented occasionally. The layers separated and the lower layer which contained the n-butyl bromide was drained into a smaller beaker. The aqueous layer was then discarded after ensuring that the correct layer had been saved by completing the "water drop test" (adding a drop of water to the drained liquid and if the water dissolves, it confirms that it is an aqueous layer). The alkyl halide was then returned to the separatory funnel. 14 mL of saturated aqeous sodium bicarbonate was added a little at a time while the separatory funnel was being swirled. A stopper was placed on the funnel and it was shaken for 1 minute while being vented frequently to relieve any pressure that was being produced. The lower alkyl halide layer was drained into a dry Erlenmeyer flask and 1.0 g of anhydrous calcium chloride was added to dry the solution. A stopper was placed on the Erlenmeyer flask and the contents were swirled until the liquid was clear. For the distillation
Abstract The purpose of this experiment is to separate a mixture of hexane and toluene by collecting fractions through simple and fractional distillation. Because hexane’s boiling point is about 68°C and the boiling point of toluene is 111°C, the two compounds distill at different times. Pure products will be analyzed with gas chromatography to determine the success of the distillation. For easy separations, a simple distillation apparatus probably will suffice, but for more difficult separations, a fractional distillation apparatus will be used in this lab. The goal is to show that fractional distillation separates the two compounds more completely because less material is lost. In conclusion the fractional distillation indeed separates the two compound
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
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
In this experiment, distillations were done. This is a technique that utilizes the differing boiling points of two or more compounds in a mixture in order to separate the compounds from the mixture. The way fractional distillation works is that the initial mixture is boiled up to the point of the lower boiling point compound; this compound then evaporates. This compound is then
We created a 3mL sample composed of isopropyl acetate and toluene in a 1:1 ratio and put it into a Hickman still to heat. While heating the sample, we observed that the solution was having difficulty reaching a boil, so we wrapped it with aluminum foil and turned up the vacuum. At 91°C, a slightly opaque white solution began filling up the empty flask. As the distillate grew, we suctioned it out and placed
With the purpose of the experiment being to identify the 30 mL of unknown liquid, the theoretical basis of simple and fractional distillation must be deconstructed and applied to the data obtained describing the liquid in question.
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.
A good yield of isopentyl acetate was obtained during this experiment. Loss of the product was likely through transferring liquid from separatory funnel to the Erlenmeyer flask and residual material left in the distillation flask. Using an organic solvent like benzene or cyclohexane as a transfer agent would improve the yield, since their boiling points were around 80 oC and could be easily separated from the final product through simple distillation. However this
As a boiling water bath was prepared, a boiling chip was added to an Erlenmeyer flask, which was then capped with aluminum foil with a small hole in the center. The flask was wiped clean of dust and fingerprints, then weighed to be 98.197 grams. About 8 mL of the unknown solution was poured into the flask, then resealed with the foil cap. The flask was placed in the water bath at an angle while making sure that no water got under the cap. Once the liquid in the flask evaporated, the flask was removed, cooled under cold running tap water, dried with a towel, and weighed again (98.562g). The temperature of the water bath was measured at this time (99.0oC). Another two trials was performed by adding more 5mL of solution to the flask and repeating
The purpose of the fractional distillation of alcohols lab was to learn a new technique to separate mixtures of our unknown compound into pure components using the specific vapor pressures of pure liquids. Before the fractional distillation lab was performed, a simple distillation lab was run. In the simple distillation setup, a boiling flask attached to an adapter holding a temperature probe. The adapter connected to a condenser into which water passed through. The condenser leads to a flask for the purified liquid. Fractional distillation was a better choice for this lab over simple distillation because
The main objective of the distillation lab was to identify the composition of an unknown binary solution. The only known component is that the boiling point of the two components were at least 40˚C apart in boiling points. Due to the difference in boiling points, fractional distillation would be an easy way to determine the identity of each component of the binary solution. In the experiment, 30mL of the unknown binary solution was ran through the fractional distillation apparatus. As the solution boiled, gas from the unknown solution ran through the column, which had a temperature gradient to allow rapid and repeated distillations, and one of the components were isolated. By recording the temperature and amount of