Perform the following with three 0.05g samples of unknown and the following solvents: methanol, water and toluene
The boiling points obtained for during fractional distillation also roughly aligned with the correct unknowns, which were Acetone (low boiling point) and Toluene (high boiling point). Any deviation in temperature may have resulted from a thermometer placed too high in the fractional column. The gas chromatography portion of the experiment produced three chromatograms with no apparent impurities. However, fraction A was found to not be purely composed of Acetone, and fraction B was not found to be a 50/50 mixture of Acetone and Toluene, yet, fraction C was found to be pure Toluene. Therefore, the calculated ratio for the mixture, 40.95% acetone and 50.046% Toluene, was greatly off from the true ratio of 25% acetone and 75% Toluene which can again be attributed to the impurities of fraction A. The retention time reported for the Toluene was accurate at .861 minutes, however, the retention time of acetone was slightly off at a value of .651 minutes when the true value is 0.64 minutes. The error of the acetone retention time may be attributed to the small presence of toluene in the fraction A sample. Conclusively, while there is error in all three sets of data the true identity of the high and low boiling point compounds are able to be correctly determined through using the combination of retention time, ratios, and boiling points to analyze which compounds align best with the overall
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
This experiment is primarily focused on the measurement of the density and the determination of the partial molar volume of ethanol-water system. A partial molar volume is a thermodynamic quantity defined as a change in volume per mole of substance added to the mixture at constant temperature and pressure, indicating that molar volumes are non-additive. Solutions of ethanol and water had been prepared with varying concentrations and a pycnometer was calibrated and used by weighing it along with the liquid samples one at a time, for the accurate measurement of the density of each mixture. The latter was measured in order to calculate for the excess molar volume and partial molar volume for both components. The data were then used for calculating other physical quantities such as molar volume, molar fraction, and molecular weight.
First. We weight the 10-ml graduated cylinder and record the data for 37.87g. Then put 5ml isopentyl alcohol and weight it with the 10-ml graduated cylinder for 41.94g. So, we get the isopentyl alcohol weight is 4.07g. Then, we also weight 7ml glacial acetic acid and put it into the 10-ml graduated cylinder. We add 1-ml sulfuric acid and put it into the 10-ml graduated cylinder too. After we mix all of the liquid, we put a boiling stone in the flask. Next, we good connection device like the picture. Then heating under reflux. Before reflux, we should check it. First, we should wait until the liquid began to boil and the color was changing to brown. Then, continue to heat for 75 minutes. After 75 minutes, we stop it. And we need to cool the liquid to the room temperature. Then we ready 10ml ice water to cool the liquid. After cooling it, we put the liquid in the separatory funnel. And we should add 5ml saturated aqueous sodium to separate it. After first separate it. Then add 5ml saturated aqueous sodium chloride to separate it. Then transfer the liquid to a 25-ml round-bottom flask. After one week, we first weight the sample mass. Then put our sample to another group’s graduated cylinder. And weight the combine mass. Then put the sample into a distillation unit. To begin the distillation and record the boiling point range. And we should also weight the mass after distillation. We can calculate the percentage yield.
The purpose of doing this experiment is to separate a sample of cyclohexane and toluene using simple miniscale distillation. The objectives will be to record boiling range and volumes (mL) of distillates that are acquired during the distillation process. It is expected that cyclohexane boils and distils before toluene. By gathering these measurements will allow us to determine refractive index of fractions collected. An Abbe refractometer will be used to accomplish this.
The purpose of this lab was to see how certain substances; Naphthalene, Toulene, and and 2 unknowns (one liquid, one solid) react with 3 different solvents. To identify the two unknowns, testing needs to be done to find the density of both the liquid and the solid, determine the melting point of the solid, and the boiling point of the liquid. The Physical Properties of Pure Substances Table can then be used to compare the observed results with the accurate properties from the table. If testing is done correctly, accurate assumptions can be made to figure out what the unknown substances were.
2-Methycyclohexanol (15mL) were added to H3PO4 (1mL) and H2SO4 (3 drops) in a 100mL round bottom flask. The distillation apparatus was assembled and the mixture was moderately heated to avoid bubbling during the distillation process. During this time, some of the equipment was not 100% secured, and some product was lost. Distillation was stopped when a black, oily substance started to form at the bottom of the flask. The distillate was collected in the Erlenmeyer flask, at the temperature of 109 degrees C. The organic layer was dried using the anhydrous MgSO4. The MgSO4 was filter off and the alkene mixture was collected. The liquid alkene was weigh.
A simple distillation was carried out involving a 30 mL pre-mixed solution of methanol and 2-pentanol in order to separate the two compounds by taking advantage of the differing boiling points. Since methanol has a lower boiling point at 64.7°C, compared to 2-pentanol’s boiling point of 119.3°C, it distilled off first. Through the use of the apparatus we set up, the solution was heated on a hot plate, the vapor that came up was cooled by the condenser into a liquid and flowed down into the receiver. Temperature was recorded for every 2 mL of distillate collected. In addition, three 10 mL distillate fractions were collected to be analyzed through gas chromatography. The purpose of gas chromatography analysis was analytical for this specific
Distillation is the process of which liquid is changed into it’s vapor state which in turn is changed by condensing the vapor back to the liquid state. This process is used to separate and purify liquids. The process begins a distillation apparatus. After the evaporation process begins and ends, the vapor will have evaporated while the purified substance will condense with cool water. In this lab, the purpose is to separate two liquids, cyclohexane and toluene or cyclohexane and p-xylene. During the process, the volume and temperature were recorded at each milliliter. This would show the different boiling points. Then using gas chromatography, we would be able to identify the correct peak. If the difference between the
This experiment consisted of a simple distillation of a hexane and heptane mixture. The first, third, and fourth fraction were taken and recorded in Table-1. The first fraction temperature ranged from 29.7°C – 38.2°C. The second fraction temperature range was recorded as 40.3°C-41.7°C, but this fraction was not used. The third fraction temperature range was determined to be 41.8°C – 36.5°C. Finally, the fourth fraction temperature range was 34.5°C-27.3°C. The ranges of the temps following the second fraction began to decrease, causing a discrepancy in the data. This decrease in data can be linked to the formation of water or condensation on the tip of thermocouple. The first, third, and fourth fractions were collected and further analyzed using
To prevent the NaOH from absorbing water from the air the initial temperature (t1) was obtained and recorded in the table. After the initial temperature was recorded from the bottom left of the screen of the Netbook, the 2.052 grams of NaOH solid were added to the cup and stirred. The data collection began after selecting Collect. Until the solution reached a peak temperature and began to drop the solution was stirred occasionally with a stirring rod being sure not the hit the temperature probe. Afterwards, the maximum temperature (t2) and the seconds it took to reach the maximum temperature was recorded in results chart. Figure 9.2 Sample: Temperature vs. Time Graph for Reaction 1 was used to confirm the initial and final temperature (t1 and t2). The metal rod of the temperature probe and the cup was rinsed wa DI water and dried. The chemicals were then disposed of safely and properly. The steps for reaction two then began. File then New were selected to reset. The same steps were then followed starting at starting at the placement of the cup into the beaker down through confirming the initial and final temperature. Some changes were made for reaction
Before the concentration profile of the distillation column could be calculated, the column had be heated to the point of equilibrium. After being heated for forty-five minutes, the binary mixture began boiling, and the equilibrium status of the column was monitored by taking temperature measurements of the mixture from the 8th tray every five minutes. The data collected is located below is Table 1.
The mass of the distillate was obtained after fermentation and the fractional distillation was calculated to be 0.195 g. The distillate was collected in three fractions using a 1 mL syringe with a needle when the temperature reached approximately 78°C. The amount of ethanol that should have been produced was 1.08 g. However, this experiment only obtained 0.195 g of ethanol product. The percent yield was calculated to be only 18.12%, so only 18.12% of ethanol product was recovered from the fermentation reaction. The density of the distillate obtained from flask one was 1.03 g/mL, flask two was 0.979 g/mL and flask three was 0.99 g/mL. The distillate in all three flasks contained mostly water and only some ethanol because the percent recovery
“Molar Mass of a Volatile Organic Liquid” lab is focused on determining the unknown substances correct label. During the lab, 3 separate Erlenmeyer flasks were filled with the same unknown clear colourless solution #3 from the back of the lab located under the fume hood. In each of the beakers it was observed to ensure that only 2ml of the unknown solvent was placed into each of the Erlenmeyer flasks. Once the unknown solvents were prepared, the hot water baths are needed to be observed to ensure that 200mL or enough distilled water was placed to fully encapsulate the Erlenmeyer flask. Both of the flasks were placed in the water at approximately the same time. After about 10 minutes, it was witnessed that the water has come to a boil due to