Name: Megan Coghlan
Lab Section: S343, Wednesday, 12:15 PM
Date: September 17, 2015
Purification of Biphenyl
Results
Methanol, acetone, dichloromethane, toluene, and hexanes were tested for their miscibility with water. Methanol and acetone were found to be miscible with water, and dichloromethane, toluene, and hexanes were immiscible. Two layers—one organic and one aqueous—were observed each time an immiscible solvent was combined with water. Dichloromethane was observed as the bottom layer, and toluene and hexanes were observed as the top layers when added to test tubes of water. In Table 1 below, density, boiling point, and miscibility with water are shown for the organic solvents used in this experiment.1
Table 1: Miscibility with Water Test
Solvent
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Biphenyl was fully soluble in dichloromethane at room temperature and partially soluble in hexanes. Biphenyl was insoluble in methanol, acetone, toluene, and hexanes at room temperature but soluble near their respective boiling points. At room temperature and at 100°C, biphenyl was insoluble in water. Biphenyl recrystallized out from hexanes and methanol at room temperature but remained dissolved in acetone and toluene.
Table 2: Solubility and Recrystallization Observations
Solvent Solubility of Biphenyl at Room Temperature Solubility of Biphenyl near Boiling Point
Recrystallization Upon Cooling? Methanol Insoluble Soluble Yes
Acetone Insoluble Soluble
The goal of this two week lab was to examine the stereochemistry of the oxidation-reduction interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. The purpose of first week was to explore the oxidation of an alcohol to a ketone and see how the reduction of the ketone will affect the stereoselectivity. The purpose of first week is to oxidize the alcohol, 4-tert-butylcyclohexanol, to ketone just so that it can be reduced back into the alcohol to see how OH will react. The purpose of second week was to reduce 4-tert-butylcyclohexanol from first week and determine the effect of the product's diastereoselectivity by performing reduction procedures using sodium borohydride The chemicals for this lab are sodium hypochlorite, 4-tert-butylcyclohexanone
In a separate beaker, acetone (0.587 mL, 8 mmol) and benzaldehyde (1.63 mL, 16 mmol) were charged with a stir bar and stirred on a magnetic stirrer. The beaker mixture was slowly added to the Erlenmeyer flask and stirred at room temperature for 30 minutes. Every 10 minutes, a small amount of the reaction mixture was spotted on a TLC plate, with an eluent mixture of ethyl acetate (2 mL) and hexanes (8 mL), to monitor the decrease in benzaldehyde via a UV light. When the reaction was complete, it was chilled in an ice bath until the product precipitated, which was then vacuum filtrated. The filter cake was washed with ice-cold 95% ethanol (2 x 10 mL) and 4% acetic acid in 95% ethanol (10 mL). The solid was fluffed and vacuum filtrated for about 15 minutes. The 0.688 g (2.9 mmol, 36.8%, 111.3-112.8 °C) product was analyzed via FTIR and 1H NMR spectroscopies, and the melting point was obtained via
The boiling point of the product was conducted with the silicone oil. Lastly, for each chemical test, three test tubes were prepared with 2-methylcyclohexanol, the product, and 1-decene in each test tube, and a drop of the reagent were added to test tubes. The percent yield was calculated to be 74.8% with 12.6g of the product obtained. This result showed that most of 2-methylcyclohexanol was successfully dehydrated and produced the product. The loss of the product could be due to the incomplete reaction or distillation and through washing and extraction of the product. The boiling point range resulted as 112oC to 118oC. This boiling point range revealed that it is acceptable because the literature boiling point range included possible products, which are 1-methylcyclohexene, 3-methylcyclohexene, and methylenecyclohexane, are 110 to 111oC, 104oC, and 102 to 103 oC. For the results of IR spectroscopy, 2-methylcyclocahnol showed peaks at 3300 cm-1 and 2930 cm-1, which indicated the presence of alcohol and alkane functional group. Then, the peak from the product showed the same peak at 2930 cm-1 but the absence of the other peak, which indicated the absence of the alcohol
As shown in figure 2, the percentage of each isomeric alcohol in the mixture had been determined. The hydrogen atom on the carbon atom with the hydroxyl group appear at around 4.0 ppm for borneol and 3.6 ppm for isoborneol. The product ratio has been determined by integrating the peaks. A ratio of 6:1 for the Isoborneol/borneol ratio was expected and is validated by the calculations shown above, with isoborneol percentage at 83.82% and 16.17% of borneol. A CHCl3 group noted at around 7ppm and a CH2Cl2 at around 3.5ppm.
When the flame was blown out and the glowing wooden splint was placed halfway into the test tube containing H2O2 and MnO2 crystals, the splint reignited and caught flame once again. This demonstrates the decomposition of H2O2 into water and hydrogen. MnO2 is a catalyst that increases the rate at which H2O2 decomposes. Adding oxygen to a fire will cause it to burn faster and hotter and the oxygen rich test tube allowed the splint to reignite.
Methionine represents the first limiting amino acid in broiler nutrition, thus different sources are available to balance diets based of corn and soybean. Bioavailability is different for each methionine source because of its rate of absorption and metabolic pathways. A broiler experiment was conducted to determine the relative bioavailability of Hydroxyl Methyl Analog Calcium (HMA-Ca) relative to DL-Methionine(DL-Met). The experiment was conducted at at Lavinesp (Unesp, Jaboticabal). It was used 1890 male broiler Cobb 500 of 21 days old, they were weighted and distributed homogeneously in a complete randomized design with 13 treatments and 7 replicates each. All birds fed either a basal diet deficient in sulphur amino acids, digestible methionine and cysteine (dig Met+Cys), or the basal diet with four levels of HMA-Ca (0.063, 0.183, 0.302 and 0.540%) and DL-Met (0.054, 0.156, 0.259 and 0.463%) to achieve increasing levels of dig Met+Cys. For the analysis, 5% of significance was considered and procedures of non-linear model were used by SAS. Exponential regression determinates bioavailability of HMA-Ca relative to DL-Met by calculating the relation of the slope of HMA-Ca relative to DL-Met
After obtaining three fraction samples of hexane, heptane, and the mixture of the two into three separate vials, gas chromatography was performed to find the relative composition of each of the three samples. For the first vial containing pure hexane, a ratio of 66.26% hexane to 33.74% heptane was determined and had a boiling point range of 69.2-76.4°C during simple distillation. The second vial containing both hexane and heptane was determined to have the ratio of 40.15% hexane and 59.85% heptane and a boiling point range of 78.2-89.0°C. The third vial containing only heptane had a
In this lab 4-tert-butylcyclohexanone is reduced by sodium borohydride (NaBH4) to produce the cis and trans isomers of 4-tert-butylcyclohexanol. Since the starting material is a ketone, NaBH4 is strong enough to perform a reduction and lithium aluminum hydride is not needed. NaBH4 can attack the carbonyl group at an equatorial (cis) or axial (trans) position, making this reaction stereoselective. After the ketone is reduced by the metal-hydride, hydrochloric acid adds a proton to the negatively charged oxygen to make a hydroxyl group. The trans isomer is more abundant than the cis based on the results found in the experiment and the fact that the trans isomer is more stable; due to having the largest functional groups in equatorial positions.
Methanol and Ethanol have differences as Methanol melts at a higher temperature and boils at a lower temperature than Ethanol. Higher alcohols, which include Butanol and Propanol, have a higher molecular weight and this is why Butanol is used in perfumes. Ethanol, which is sugar based, with its low freezing point, has a specific use as an antifreeze for cars and other vehicles. GRAPH Tripod Matches Goggles Method: To begin with, I choose one of the four different alcohols. I weigh beforehand in the spirit burner.
In order to separate the mixture of fluorene, o-toluic acid, and 1, 4-dibromobenzene, the previously learned techniques of extraction and crystallization are needed to perform the experiment. First, 10.0 mL of diethyl ether would be added to the mixture in a centrifuge tube (1) and shaken until the mixture completely dissolved (2). Diethyl ether is the best solvent for dissolving the mixture, because though it is a polar molecule, its ethyl groups make it a nonpolar solvent. The compounds, fluorene and 1, 4-dibromobenzene, are also nonpolar; therefore, it would be easier for it to be dissolved in this organic solvent.
Alcohol, which is the nucleophile, attacks the acid, H2SO4, which is the catalyst, forming oxonium. However, the oxonium leaves due to the positive charge on oxygen, which makes it unstable. A stable secondary carbocation is formed. The electrons from the conjugate base attack the proton, henceforth, forming an alkene. Through this attack, the regeneration of the catalyst is formed with the product, 4-methylcyclohexene, before it oxidizes with KMnO4. In simpler terms, protonation of oxygen and the elimination of H+ with formation of alkene occurs.
Almost every molecule in a solid moves, but it’s called a solid mainly because all of the molecules are very compacted and don’t have a lot of room to move.
Performing this experiment, we used the technique called Acid-Base extraction to isolate Eugenol, which is one of the main ingredients of clove oil. Acid-Base extraction is the most efficient method for isolating organic component; it is efficient because it purifies the acid and base mixture based on their chemical identities. We have seen throughout this experiment that acid and base play an important role, when it comes to solubility in water. Our basic knowledge of acid and base is acid is a proton donor and base is a proton acceptor. This ideology helps us to understand why organic compounds are not soluble in water. When compounds tend to be insoluble, we have to use acid and base reaction, to change its solubility. The changes that occurred
1-Butanol with intermediate polarity was soluble in both highly polar water and non polar hexane as 1-butanol can be either polar or non polar compound. 1-Butanol was polar based on the general rule of thumb stated that each polar group will allow up to 4 carbons to be soluble in water. Also, 1-butanol can be non polar due to their carbon chains, which are attracted to the non polarity of the hexane.
The solubility of a substance is defined as its ability to dissolve. There are some factors that alter solubility, such as pressure and the type of solvent, but will temperature affect the solubility of a substance? The investigation problem is to identify whether or not the temperature of a substance affects its ability to dissolve in another substance. Understanding solubility and the processes that undergo is very important, this is due to the important role that it plays in our daily life as well as in the human body. When it comes to oral ingestion, especially in drug delivery, it is profitable since it permits to deliver the medicine throughout the system in order to gain positive and desired responses. Meanwhile it is seen in the human body, it is also manifested while doing household cleaning and in automoviles. That’s why it is essential to recognize and know what is solubility in order to be able to control, manipulate, and enhance it as well as get informed of how life works by depending on water and chemical reactions.