This aqueous solution was then heated until all the dichloromethane evaporated off. An error could have occurred at this point in the experiment if the hot plate was too hot. If the hot plate was set above the boiling point of the ketone, the ketone could have evaporated of along with the dichloromethane. This would result in a lower percent yield of the ketone. To prevent this from happening, the hot plate should not exceed 130˚C, so no matter what ketone was isolated, it would not evaporated off. At this point I found that if the hot plate was at 147˚C the solution boiled more vigorously, meaning that my ketone hade a boiling point of 147˚C, which was close to the known boiling point value for 3-heptanone, 146˚C. The hot plate was turned down after this was noticed. After the solution was heat, approximately for five minutes, the mass was found for the bottom layer, which was 2.27g, and the percent yield was calculated. The percent yield was determined by taking the mass of the final ketone and dividing it by the original mass of the alcohol. The percent yield was calculated to be 129.7%. This high percent yield resulted from the presence of
The reaction mixture was created. Tetraphenylcyclopentadienone (0.1197g, 0.3113 mmol) a black solid powder, anthranilic acid ( 0.0482g, 0.3516 mmol) a yellowish sand, and 1,2-dimethoxyethane (1.2 ml) was added to a 5-ml conical vial. A spin vane was added and a water-jacked condenser was attached. Isopentyl nitrite (0.06ml, 0.045 mmol) was dissolved in 1,2-dimethoxyethane (0.50 ml) in a 3-ml conical vial and caped to prevent loss by evaporation.
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
In this experiment, the percent yield was 90%. This number implies that there was little error in this experiment. However, this result could have been caused by certain external factors. Firstly, because the NaHCO3 compound was not stored in a sealed container, therefore dust particles could have changed the results, and making the product impure. Also, there are uncertainties associated with the instruments used in this experiment. This, if the products were measured slightly more than should be, this could have affected the concentrations of the solutions, and therefore causing a larger
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
The goal of the experiment is to synthesize a bromohexane compound from 1-hexene and HBr(aq) under reflux conditions and use the silver nitrate and sodium iodide tests to determine if the product is a primary or secondary hydrocarbon. The heterogeneous reaction mixture contains 1-hexene, 48% HBr(aq), and tetrabutylammonium bromide and was heated to under reflux conditions. Heating under reflux means that the reaction mixture is heated at its boiling point so that the reaction can proceed at a faster rate. The attached reflux condenser allows volatile substances to return to the reaction flask so that no material is lost. Since alkenes are immiscible with concentrated HBr, tetrabutylammonium bromide is used as a phase-transfer catalyst. It forms a complex with HBr and extracts it from the aqueous phase into the organic phase where the alkene is. This dehydrates the acid, making it more reactive so that the addition reaction is possible. Rapid stirring is required in order to maximize the surface area
Abstract – Methyl trans-cinnamate is an ester that contributes to the aroma of strawberry. It can be synthesized by an acid-catalyzed Fischer esterification of a methanol and trans-cinnamic acid under reflux. The solution was extracted to obtain the organic product, and evaporated residual solvent The yield was 68%, but there is some conflicting data regarding the purity. The melting point, IR, GC-MS indicate a highly pure desired product whereas 1H NMR shows there are unreacted reagents still present.
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 purpose of this experiment is to undergo bromination reaction of acetanilide and aniline to form 4-bromoacetanilide and 2,4,6-tribromoaniline respectively. Since -NHCOCH3 of acetanilide and -NH2 of aniline are electron donating groups, they are ortho/para directors due to resonance stabilized structure. Even though the electron donating groups activate the benzene ring, their reactivities are different and result in the formation of different products during bromination. In acetanilide, the lone pair of the nitrogen is delocalized into the
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.
Ribonucleotide reductase, the rate-limiting enzyme for de novo DNA synthesis, is an excellent target for chemotherapy. Its increased activity in cancer cells is associated with malignant transformation and proliferation.
The percent yield was 22.33%. In most cases, that means that a lot of possible product was lost. However, in this case, that was not true. When Benzaldehyde reacted with the Wittig reagent, it produced two products: E-Stilbene and Z-Stilbene. The Z product was a liquid, while the E product was a solid. The final product weight for percent yield was only the solid E product, which missed one half of the final product produce. If both products were weight, the percent yield would have been larger that it was. Instead of 22.33%, it could have been 44.66%.
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
Tertiary alkyl halides tend to give a mixture with both inverted and retained configurations at reaction centers. This is because this reaction proceeds through a stable carbocation intermediate and the carbon at the reaction center goes to sp2 hybridized state (planar geometry). The incoming nucleophile can attack from both sides of the plane and can give two products with retained and inverted configuration. If there is a partial interaction with the leaving group (nucleofuge) with carbocation there will be more product with inverted configuration and if there is no interaction with leaving group racemic mixture can be obtained. The rate of the reaction depends on the formation of a carbocation (which is the slow step) and there is one molecule