Methanol And Water Procedure: A Case Study

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

1.5mL of phosphoric acid including 3-4 boiling chips were also added to the 25mL flask. The short path distillation apparatus was set up as shown in Figure 1. A heating mantle was used to heat up the 25mL flask. The solution was distilled to the receiving flask until a small amount of liquid remained in the initial RBF flask. At this point the presence of thick grey smoke pulling over into the entire apparatus was observed. The apparatus was then left to cool down. Through the use of pasture pipette, the aqueous layer from the distilled solution was drawn out. Sodium carbonate was then added to the remaining organic solution in order to check the pH and to verify the basicity of the solution. The aqueous layer was again drawn out from the solution. Next, 0.5g of sodium sulfate was added to the remaining organic layer and was swirled until the liquid appeared to be dry and clear. The alkenes were transferred into a clean 10mL flaks using another clean pasture pipe. The apparatus from the first distillation was rinsed off with

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.

The decanted liquid had to be placed back into the freezer in order to refreeze the crystals to allow them to be decanted off. This could have caused a portion of the product to have been lost, thus affecting the percent yield and purity of the final product. Furthermore, there was an oiled substance thought to be a contaminant in the product after the addition of hot methanol and hot water to the Erlenmeyer flask. This contaminant was left in the Erlenmeyer flask to see whether or not it had an effect on the final product, but once the activated charcoal was added into the Erlenmeyer flask, the contaminant seemed to have latched onto the charcoal. Since it latched onto the charcoal and the charcoal was filtered out by way of gravity filtration, the contaminant is thought to have been filtered out as well. While the contaminant seemed to have been filtered out by the gravity filtration, there could be a small portion of the contaminant that remained in the filtered-out product, thus affecting the percent yield and purity of the final product as

The remaining organic layer was washed with sodium bisulfite and brine. The sodium bisulfite was used to wash away MgOH and neutralize the acid. The solution was dried using anhydrous sodium sulfate and heated until the solvent evaporated. Anhydrous sodium sulfate is a drying agent used to remove water from the mixture. The crude mixture was triturated in petroleum ether. Trituration broke down the crude mixture into a desirable compound that remained insoluble, and impurities, which were soluble in the liquid. Therefore, the impurities were filtered out using petroleum ether. This rinsed away the non-polar byproduct,

After 20 mL of methanol, 2.91 g of 2-naphthol, 1.71 g KOH, and a few boiling chips were combined in a small round-bottom flask and allowed to react, 1.8 mL iodoethane was added. The mixture was boiled for two hours with a reflux condenser; after adding 50 mL of cold water, the flask was sealed with a plastic stopper and parafilm and stored in a freezer for several days.

Although some product was lost during transfer of solutions and venting during extraction, the overall yield was acceptable. The silver nitrate and sodium iodide tests performed to ascertain the gross structure of the C-Cl bond and the IR signature obtained from analyzing the product both pointed to 2-chloro-2-methylbutane being the result of the protocol, as the halide tests indicated the chlorine was attached to a tertiary carbon and the IR indicated no -OH bonds or carbon-carbon double bonds, which would be indicative of an elimination reaction, were present in the molecule; thus the 2-chloro-2-methylbutane product was relatively

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.

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

Ethanol is usually recommended to treat methanol poisoning because the ethanol slows down the metabolization of methanol, until the methanol is eliminated from the body. Ethanol can delay the metabolization of methanol because they are both metabolized by antidiuretic hormone, however this enzyme’s affinity for ethanol is 10-20 times higher than it is for methanol. The second reason is that ethanol uses competitive inhibition to outcompete methanol and bind to the enzyme Alcohol Dehydrogenase, therefore the methanol is excreted by the kidneys without being turned into

The purpose of this experiment was to use solvent extraction techniques in order to separate a mixture consisting of a carboxylic acid (p-toulic acid), a phenol (p-tert-butylphenol), and a neutral compound (acetanilide). Extraction is the process of selectively dissolving one or more of the compounds of a mixture into an appropriate solvent, the solution that contains these dissolved compounds is called an extract (Manion, 2004).

The purpose of this experiment is to purify a mixture of compounds in order to separate it into its pure components, using the common methods of extraction, gravity filtration, vacuum filtration, and drying organic solutions. Extraction is a common laboratory technique used to isolate and purify the product of a chemical reaction. The principle behind this method is that a solute is transferred from one solvent into a second solvent that it is more soluble in. Therefore, the two solvents must be immiscible and form two distinct layers. Generally, one solvent is aqueous and the other is organic.

Methanolic extraction and hot water extraction were performed in duplicate for all tea samples. To prepare the methanolic extraction, 25 ml of methanol was added to 1 g of tea sample. For complete extraction, ultrasonication was performed for 15 minutes at room temperature. Following ultrasonication, tea samples were filtered through 0.45 µm cellulose acetate membrane filter (VMR International) and stored at -20oC until analyses. In addition to the methanolic extracts, hot water extraction was performed to mimic the homemade tea preparation. To prepare the hot water extraction, 1 g of tea sample was dissolved in 25 ml freshly boiled water and incubated for 7 minutes in a covered glass bottle and stirred three times with

Extraction solvent was ethanol (70%, v / v) and hydrochloric acid (0.01%, v / v). Ethanol is more environmentally friendly than methanol. However, did authors compare the use of methanol under the optimized conditions.

In this experiment were used three separation techniques: extraction, sublimation and recrystallization. During the first method, 0.70 g sample of salicylic acid-naphthalene mixture was dissolved in 10 ml of diethyl ether. The solution was placed in a separatory funnel and 10 ml of saturated aqueous sodium bicarbonate solution was added to it. After the initial gas was