Purification Of Solids Lab Report

Which solute did not appear in the filtrate using any of the membranes? Powdered Charcoal

Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.

This Lab Report is an analysis of the results of a two-part experiment. In the first part, we used a gel filtration column to separate the components of a mixture composed of protein and non-protein molecules. By doing so we hoped to obtain fractions that contained single components of the mixture, while also gaining insight into the relative molecular weight of each component compared to each other. We would then plot these fractions onto nitrocellulose paper in order to determine which fractions had protein. In the second part, we would use the fractions which we had determined had protein to conduct an SDS-PAGE. By doing so we hoped to determine an estimate on the molecular weight of the proteins present in each fraction by comparing it to a tracker dye composed of a variety of molecules of differing molecular weight.

4- chlorobenzoic acid which was the aqueous layer has a theoretical melting point of 240-243°C, the organic layer, 4-chlorobenzyl alcohol has a theoretical melting point of 68-71°C. During our experiment we were unable to collect any data for the organic

The manufacturer results shows that Alka-Seltzer has 1.9 grams per tablet. In the experiment the results are too small compared to the number that is given by the label. In the first run only .0588 grams reacted to the acid. That suggest that the tablet only contains 0.588 grams of sodium bicarbonate which is very different from the manufacturers. The second run gave an even smaller number of gram. In terms of moles only .0007 reacted in the first and third run and only .0006 in the second run. There are many factor that could had alter the amount of moles that reacted to the acid which affected the result in showing that there is a smaller composition of sodium bicarbonate in the tablet than that of the manufacturer’s.

Examine a piece of nichrome wire. On the data sheet, record the color and the luster of the metal. Use a forceps to hold the wire in the flame of your burner for about two minutes (recall where the hottest part of the flame is located). Describe the appearance of the wire while held in the hottest part of the flame. Allow the wire to cool and reexamine it. From your observations, determine if there was a physical or a chemical change. Give specific reasons for your conclusions. Save the nichrome wire for step #2.

The product yielded in this reaction was adipic acid (Figure 1), a white crystalline solid substance at room temperature, which can be deprotonated twice. Adipic acid is an important industrial chemical used in the synthesis of nylon. Adipic acid has the molecular formula, C6H10O4, the molecular weight 146.14 grams/mol, a melting point of 153 °C, and a density of 1.36 g/cm3. (PubChem.com)

Strontium nitrate, the limiting reagent, was poured into the copper(II) sulphate solution, the excess reagent, rather than the other way around. This is a minor systemic error, because even if some of the strontium nitrate remained in its initial beaker, the beaker was thoroughly rinsed out multiple times. The error causes the final mass of the filter paper and precipitate to be slightly decreased, as not all of strontium nitrate reacts with the copper(II) sulfate. This can explain why the percent yield in 92.2%.

In the first part of the experiment trans-cinnamic acid began to melt rapidly at 133 °C and had completely liquefied at 135.9 °C. Urea began to melt rapidly at 133 °C, just as the trans-cinnamic acid, but had completely liquefied at 134.7 °C. Both urea and trans-cinnamic acid had true melting points of 132 °C generating a .75 percent error. The 50:50 mixture of urea and trans-cinnamic acid started to melt quickly at 98.5 °C, slowed down at 102 °C, at which point most of the compound had seemed to have melted with the exception of a few crystals, which did not melt completely until 125°C . In the second part of the experiment, the melting point of an unknown compound was measured at a fast rate, 10 °C/min, in order to obtain an estimate of the melting point of that compound, which was about 130 °C – 139 °C. At this point the suspected organic compound was benzoin, and the melting points of the two compounds, benzoin and the unknown, as well as the 50:50 mixture of each, were obtained. The unknown compound, along with the benzoin, had identical melting points of 133.7°C – 134.9°C, while the 50:50 mixture had a melting point of 133 °C – 134.3 °C. The true melting point for benzoin is 132°C, generating a .75 percent error.

Beakers 5-8 were set aside for later use. I then recorded by observation of beaker 1 in Table 1 on the Lab Reporting Form; this included smell, color, etc. 10 mL of vegetable oil was added to beaker 2, 10 mL of vinegar to beaker 3, and 10 mL of liquid laundry detergent to beaker 4. Each beaker was mixed thoroughly with a wooden stir stick. My observations such as color and smell were annotated in Table 1 on the Lab Reporting Form. Next, I cut the cheesecloth into five different pieces. I took one piece of cheesecloth and folded it so it was 4 layers thick. I then placed it into the funnel. 60 mL of soil was measured out using the 100 mL beaker and placed into the cheesecloth lined funnel. The funnel was then put inside beaker 5. The contents of beaker 1 (water) were poured through the funnel and let filter for 1 minute into beaker 5. My observations were recorded on Table 1 on the Lab Reporting Form. I repeated the process of creating a filter of cheesecloth and soil and filtered the contents of beaker 2 (vegetable oil) into beaker 6, beaker 3 (vinegar) to beaker 7, and beaker 4 (detergent) to beaker 8. All observations were recorded on Table 1.

Discussion: As seen in the melting point determination, the average melting point range of the product was 172.2-185.3ºC. The melting points of the possible products are listed as 101ºC for o-methoxybenzoic acid, 110ºC for m- methoxybenzoic acid, and 185ºC for p- methoxybenzoic acid. As the melting point of the sample

organic compounds. The goal of this technique is to allow organic compounds to form crystal

An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water

Step 1 and 2 was repeated by using distilled water by replacing the test solution.

Subsequently, 10mL of 3.5% H2O2 were added dropwise to the reaction mixture and was stirred for 20 minutes before heating to boiling at 80°C for 5 minutes. The reaction mixture was then taken off heat and allowed to cool undisturbed in an ice-bath for 30 minutes. Suction filtration was performed after to collect the crystals from the chilled solution The product was then washed with chilled 95% ethanol (2 x 15mL) and followed by diethyl ether (2 x 10mL). The crude product was then left to dry before recording the yield. 20mg of the crude product is then accurately weighed out and dissolved in deionized water in a 25mL volumetric flask. Deionized water was added to the volumetric flask to the mark and the UV-vis absorption spectrum of the crude product was recorded.