Thiamine Hydrochloride Lab Report

An Erlenmeyer flask was used to accommodate the largest volume of recrystallization solvent calculated and was cooled in an ice bath to increase the yield of crystals. The solid was collected by vacuum filtration and washed with a small amount of ice water. The product is then dried to a constant mass by use of an oven and weighed. A small amount of the unknown was compared to two samples of acetanilide and phenacetin for a melting point range to determine the identity. The temperature of the unknown was recorded when the first trace of liquid can be seen and when the unknown was completely liquid.

Stoichiometry is a very important part of chemistry. Stoichiometry refers to calculating the masses of molecules and their products . The reactants are usually given and stoichiometry is used to find the products of the equations as well balancing the equation. An example of this would be sodium chloride (NaCl). Stoichiometry will say that if there are ten thousand atoms of sodium and one atom of chlorine, only one molecule of sodium chloride can be made and that fact can never be changed.

The mixture was transferred to an ice bath to crystallize the product, after which the product was collected by vacuum filtration on a Hirsch funnel, washing the flask with small aliquots of cold xylene and pouring the solution over the crystals, allowing the vacuum to thoroughly dry the product. Additional drying was achieved by transferring the product to filter paper and pressing the crystals to remove any excess moisture. The product was then weighed and a melting point determined. A comparative TLC was run in Hexanes:Ethyl Acetate solvent against maleic anhydride to verify the purity of the

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.

The product was placed in a Craig tube and several drops of hot (100°C) solvent (50% water, 50% methanol, by volume) was added and heated until all of the crystals dissolved. The Craig tube was plugged and set in an Erlenmeyer flask to cool. Crystallization was induced once the mixture was at room temperature by scratching the inner wall of the tube. It was then placed into an ice bath for ten minutes until crystallization was complete. The tube was then

21) After all of the solid dissolves, move the flask from the hot plate and allow it cool to room temperature. After a while, crystals should appear in the flask.

Once the distillate had been collected into two separate vials, both distillates were washed with aqueous sodium bicarbonate (1.5-ml, 5%). The aqueous layer (lower) was extracted from both vials using a pipette and put into a chemical waste bin. The organic (alkene) layer was then dried with anhydrous calcium chloride pellets (3 pellets per vial). Both distillates were analyzed using gas chromatography, and each peak shown was identified to be one of the alkenes. Analysis of the graph was used to determine the major and minor products of the reaction.

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The reaction is carried out in saturated aqueous ammonium chloride solution. Thus no special drying of solvents, reagents, or glassware is required. The reaction mechanism for this experiment can be seen below (Fig. 2)

The pipet was put into the top of the condenser and leaving no open spaces. The vacuum served to get rid of the nitrogen oxide gases that were formed during the oxidation reaction. The solution was heated for 30 minutes, beginning the time when the first sign of nitrogen oxide fumes were observed. After the 30 minutes, the solution was removed and cooled for a few minutes. The solution turned was a brownish-yellow color and all the crystal were dissolved, leaving a liquid. The solution was then transferred, using a Pasteur pipet, to 3 mL of water in a beaker. The reaction flask was rinsed to remove the remainder of the solution. The solution was stirred with a glass rod until room temperature of the solution was achieved. A yellow solid was to form, but instead the solution remained aqueous in the case of the specific experiment explained here. With additional scraping of the solution with a glass rod, no crystals formed at all. The next procedure, if the crystals had formed was to crush the solid with the glass rod and filter the solid until the crystals were dry. The mass would then be weighed and the crystals were to be recrystallized with 95% ethanol. The crystals were to be cooled in ice water to get full crystallization and then the crystals were to be filtered and air dried, then weighed.

The week after, a recrystallization was performed on the previous week’s crude product. The product ethereal solution was first heated on a steam bath until dry. During the heating, a beaker of methanol was collected and also placed on the steam bath. Once the product was dry, it was cooled to room temperature and then placed in an ice-water bath. The now boiling methanol was added to the crude crystals and a recrystallization was performed. Once completed, the now purified product was collected via Buchner vacuum filtration and stored in drawer to dry for a week. Afterwards, a melting point range of the purified product was obtained by using a Mel-temp apparatus. Lastly, an

The result was small white crystals, which were dry and had barely contained any moisture. The product was then dissolved in methylene chloride and dried with granular anhydrous sodium sulfate. The drying agent would have removed any water in the solution and presented a colorless solution. The solvent was evaporated and the product was collected; it had the appearance of small, white solids. Data Table 2 shows the results and calculations that were gathered after the completion of this experiment. A boiling point of the product was found to be 210℃. According to literature, the boiling of isoborneol should be 212℃. As a result, the product is most likely isoborneol. No errors had occurred during the course of the experiment, which is testified by the high yield of

The main material of this experiment was HCT-116 ( human colorectal carcinoma) cells where RNA isolated. Method was applied with Rneasy Mini Kit- Qiagen. Homogenization was done by 70 % ethanol. Microcentrifuge and its tubes, pipettes, pipette tips and gloves were other materials of this experiment.

To do this, a hot water bath was prepared and by placing 250 mL of deionized water into a 600 mL beaker and heating it to 70˚C using a hotplate. An Erlenmeyer flask with 70 mL of deionized water was placed into the hot water bath. When the temperature of the hot water bath was at a constant 70˚C, 0.000 g of FeCl3 and 0.000 g of FeSO4· 7 H2O were added to the Erlenmeyer flask. The flask was swirled around in order to dissolve any solid compounds before being removed from the hot water bath. 20 mL of 2.5 M NaOH was then added drop wise to the solution, so that a black precipitate formed. The solution was allowed to cool before being placed in a centrifuge for 5 minutes at 4000 rpm. The supernatant was then removed, and deionized water was poured over the precipitate to fill the centrifuge tube. Once again, the solution was centrifuged for 5 minutes at 4000 rpm, and the supernatant was removed. The remaining solid, which would ultimately harden to form clay, was removed from the centrifuge tube using a spatula and placed in a beaker to dry for 7

Crystals were collected in a Buchner funnel, washed with alcohol, then ether, then transferred into a sample tube for storage.