In this lab, the oxidation of a secondary alcohol was performed and analyzed. An environmentally friendly reagent, sodium hypochlorite, was used to oxidize the alcohol, and an IR spectrum was obtained in order to identify the starting compound and final product. The starting compound could have been one of four alcohols, cyclopentanol, cyclohexanol, 3-heptanol, or 2-heptanol. Since these were the only four initial compounds, the ketone obtained at the end of the experiment could only be one of four products, cyclopentanone, cyclohexanone, 3-heptanone, or 2-heptanone. In order to retrieve one of these ketones, first 1.75g of unknown D was obtained. 1mL of Acetic acid was then added to Unknown D and the solution was stirred. Next, 15mL of sodium
Bromination is the process where an alkene is halogenated with bromine. The purpose of this experiment was bromination of stilbene to stilbene dibromide. The element bromine is toxic and requires maximum care when used. Bromine was generated in the reaction mixture by using a green method. Less hazardous reagents were used to do so. This can be seen by the chemical reaction 2HBr+H_2 O_2→〖Br〗_2+2H_2 O. Hydrogen peroxide is used to oxidize HBr to 〖Br〗_2. By adding hydrogen peroxide this can make working with bromine less dangerous. This experiment is a greener approach to the bromination process because ethanol was used as a solvent. Ethanol is nontoxic making the experiment less harmful.
The yellow solution containing the reactants was slowly poured into the beaker containing the cold water and the acid in order to cause the precipitation of the alcohol, 9-fluorenol and to destroy (hydrolyzed) the unreacted excess sodium borohydride. Subsequently, the white precipitate was vacuum filtered and washed twice with 20.0 ml portions of distilled cold water by pouring the liquid into the Buchner Funnel during filtration. It was necessary to wash the alcohol prior to recrystallization considering that the C-OH bond is easily broken by the formation of a stable and benzylic carbocation that favors the synthesis of difluorenyl ether. Finally, before the purification by recrystallization of the obtained product, the white solid alcohol was allowed to dry over a period of a
A Sn2 reaction was conducted; this involved benzyl bromide, sodium hydroxide, an unknown compound and ethanol through reflux technique, mel-temp recordings, recrystallization, and analysis of TLC plates.
The objective of the Bromocresol Green Equilibrium System Lab was to determine if the equilibrium constant, K, was a true constant at constant temperature. To determine this, the value of the constant was found at different concentrations of HIn, HIn-, and at varying pH, which was used to determine the concentration of H+. K was found using the equation K= [HIn]/([In-][H+]). In order to be a true constant, none of the values of K found should differ from the average by more than two standard deviations. The values of K for solutions 1-5 and U were 4.39E4, 4.53E4, 4.23E4, 4.70E4, 6.35E4, and 4.03E4 respectively. The average K for the lab was found to be 4.71E4 and the standard deviation was 8.302E3. The range then that all experimental values of K must fall under is 3.05E4 to 6.37E4. All experimental values of K for this trial fell within the range. Therefore, K can be determined a true constant.
As seen in table 1, the theoretical yield was .712 g of C_17 H_19 NO_3. The % yield of this experiment was 7.51 % of C_17 H_19 NO_3. . This low yield can be explained from a poor recrystallization technique combined with potential contamination. Throughout the experiment, the mixture changed color from green, orange, to yellowish lime, and eventually clear. These color changes indicate a chemical change, which show that a reaction had occurred. In the first step when o-vanillin and p-toludine, imine was formed. The color change from green to orange suggests that imine appears as orange colored. In the second step, the addition of sodium borohydride reduced the imine into another derivative, which was yellowish lime color. The solution turned clear when acids and anhydrides was added, which indicated the precipitate were dissolved. However, after refluxing for a while, yellow precipitates begin to form near the top of the flask. It was assumed that the remaining starting material was concentrated from a decrease volume to reappeared in solution. Nevertheless, this may have been a sign of contamination that will negatively affect the entire reaction. This observation later resulted in a yellowish
After adding the acetic acid and hydrobromic acid to the solution, and heating and recrystallizing the solution, the product triphenylmethyl bromide was created and had a mass of 0.103 g. The theoretical yield was calculated by determining the limiting reagent in the reaction. The triphenylmethanol was the limiting reagent in the reaction. The total amount of mass from the triphenylmethanol was converted to moles by using the molar mass of the triphenylmethanol. The amount of moles was then converted into grams to determine the theoretical yield, 0.125 g. The percent yield was then calculated by dividing the actual yield by the theoretical yield and multiplying the result by 100%. The percent yield was 82.4%. The melting point of the product was observed to be 139.5 °C. The theoretical yield of the product is 152 °C (University of South Carolina Department of Chemistry and Biochemistry). The melting point percent difference was calculated by subtracting the theoretical melting point from the actual melting point, dividing the result by the theoretical melting point, and multiplying the result by 100%. The melting point difference was 8.22%. Example calculations are shown
An endospore is a dormant of a bacterial cell. It is a non-reproductive structure that ensures survival of a bacterium through stressful environmental conditions. Unknown #76, using aseptic technique, was inoculated to a nutrient sporulation medium (NSM) plate. This concerns a selective medium that increases the initiation of endospore production. A spore-former would have green-pigmented endospore cells when looked at under the microscope. From the growth on the NSM, I smeared it aseptically to a wet slide. Slide was then left to be air-dried for about 10 minutes. It was important to heat fix the slide using a micro incinerator. The succeeding steps had to be taken with caution because the primary stain, malachite green, is toxic. Under the hood, the slide was covered with a properly cut size of paper towel. The slide was then stained and left to steam with malachite green. It was continuously followed up by applications of the stain so it may remain moist for 10 minutes. The slide was then rinsed and safranin was again used as a counterstain. Using oil immersion objective lens of the microscope, unknown #76 had only reddish-pink cells without any signs of spore formation. Thus the given unknown is a non-spore former. Bacillus subtilis was used for positive control and Escherichia coli for negative control for endospore
The goal of this experiment was to isolate three different molecules (acidic, basic, and neutral) from a mixture and identify their molecular structure. This was accomplished by using acid/base liquid extraction and H NMR analysis.
In this experiment, it was possible to produce the major products from bromination of acetanilide and aniline. 0.075g of 4-bromoacetanilide and 0.156g of 2,4,6-tribromoanilne were collected from bromination of 0.07g acetanilide and 0.05g aniline with the percent yield of 67.57% and 88.1% respectively. At the end of the experiment, to prove the formation of the major products, melting point of the products were measured. The melting point of the product from the bromination of acetanilide was 164.8-168.50c, which is in the range of the melting point of 4-bromoacetanilide, 165-1690c, as reported on the Chemical Book, CAS Database List (chemicalbook.com). The melting point of the product from the bromination of aniline was 119.8-121.90c, which is in the range of the melting point of 2,4,6-tribromoaniline, 120-1220c, as indicated on PubChem, Open Chemistry Database (pubchem.ncbi.nlm.nih.gov). This verified the formation of the major products. Overall, one can say that the experiment was
A milk-based, litmus broth tube is incubated and observed after 48 hours. Observations include lactose fermentation without gas as well as with gas, the reduction of litmus, casein protein coagulation and casein and protein hydrolysis. These characteristics were all determined based on the color of the solution and the production of a curd, the curds density and the production of a gas. To determine the density of the curd, the tube was slightly turned to see rather or not it was mobile or concentrated towards the bottom.
On April 6, 2016 at approximately 11:45am, a local police station got a call about a hostage situation at a local pharmacy. When police and medical examiners got to each crime scene, they learned that all of the hostages were given drugs and had overdosed on them. Some of the pills, in powder form, were found near the victims. One of the victims was stable enough to tell the investigators that the power on the floor were the drugs they were forced to take. The medical examiner found out each hostage was given either unknown A or unknown B. Both being over the counter drugs. The medical examiner narrowed down the list of 5 possible pain relievers and 3 antacids the unknown drugs could be. The purpose of this lab is to identify what the unknown
Prove if the material in cup 6 is a metal, metalloid, or nonmetal, by using its appearance, color, state of matter, luster, conductivity, malleability, and how it reacts with HCL.
There are several factors which affect the rate of reaction: catalyst, reactant concentration, and temperature.1,2
Biochemical tests are the tests used for the identification of bacterial species based on the differences in the biochemical activities of different bacteria. Bacterial physiology differs from one species to the other. These differences in carbohydrate metabolism, protein metabolism, fat metabolism, production of certain enzymes and ability to utilize a particular compound help them to be identified by the biochemical tests. Gram’s stain was originally devised by histologist Hans Christian Gram in 1884. Gram-positive bacteria stain purple, while Gram-negative bacteria stain pink when subjected to Gram staining. Approximately 60-90% of the Gram-positive bacterial cell wall is made up of peptidoglycan and interwoven teichoic acid, while only