When we added the 1% silver nitrate to the alkyl halides in the first part of the experiment the first two test tubes, containing 2-bromo-2-methylpropane and 2-bromobutane, became cloudy almost immediately. The 2-bromo-2-methylpropane and 2-bromobutanes’ cloud was light green in color. The 1-bromobutane precipitated, though more slowly than the first two tubes, and its cloud was white. We also noticed that the 1-chlorobutane never seemed to become cloudy or precipitate. This is likely because chloride is a worse leaving group than bromide is (due to the chloride anion being a smaller ion, it can’t “handle” the negative charge as well as the larger bromide anion, so it doesn’t want to leave the carbon it’s sharing the electron with in 1-chlorobutane).
Atoms are the basic units of matter and all life is based on them. Life on earth is based on the element carbon. It is a highly versatile atom able to form four covalent bonds with itself or other atoms such as hydrogen and water. Atoms combine to form molecules and those that are carbon based are referred to as organic molecules. Organic molecules occur in four different types in living cells; carbohydrates, lipids, proteins and nucleic acids. They are also known as hydrocarbons due to the presence of both hydrogen and carbon. Carbohydrates are made up of carbon, hydrogen and oxygen in the ratio 1:2:1. They are important sources of energy and are classified in three main groups; monosaccharides, disaccharides and polysaccharides.
What is the stereochemistry for the bromination of trans-cinnamic acid, and how is it formed?
Introduction This experiment was undertaken in order to create stilbene dibromide. Bromine is added through electrophilic addition in attacking the double bond. This experiment was also executed to determine the stereochemistry of this addition reaction, whether it created meso products or d,l products. Data and Results Initially, 0.9 grams of stilbene were added to the solution.
Samples of benzophenone, malonic acid, and biphenyl were each tested with water, methyl alcohol, and hexane. Benzophenone was insoluble in water as it is nonpolar while water is highly polar. Benzophenone was soluble in methyl alcohol, dissolving in 15 seconds, because methyl alcohol is intermediately polar as benzophenone is nonpolar. Methyl alcohol is polar but not as much as water. Thus, the nonpolar benzophenone was soluble in methyl alcohol. Benzophenone was partially soluble in hexane because hexane is nonpolar as is benzophenone. Thus, benzophenone was dissolved in hexane. Malonic acid was soluble in water because both malonic acid and water are polar. It took 25 seconds for malonic acid to dissolve in water. Malonic acid was soluble in methyl alcohol because malonic acid is polar and methyl alcohol is intermediately polar, allowing malonic acid to dissolve in the methanol in 15 seconds. Malonic acid was insoluble in hexane because hexane is nonpolar while malonic acid is polar. Biphenyl was insoluble in water as water is highly polar whilst biphenyl is nonpolar. Biphenyl was partially soluble in methanol which is intermediately polar whilst biphenyl is nonpolar, allowing it to dissolve a little. Biphenyl was soluble in hexane because both biphenyl and hexane are nonpolar molecules. Biphenyl dissolved in hexane in 10 seconds.
In order to isolate benzoic acid, benzocaine and 9-fluorenone, each component needed to be separated from one another. All three compounds began together in one culture tube, dissolved in methylene chloride and formed into a homogenous mixture. In this culture tube, two milliliters of aqueous three molar hydrochloric acid was added, which immediately formed two layers, the top acidic aqueous layer was clear in color and contained benzocaine, and the bottom organic formed was yellow and contained benzoic acid and 9-fluorenone. Benzocaine’s amino group is protonated by the aqueous layer hydronium. This protonation forms the conjugate acid of benzocaine, benzocaine hydrochloride. Thus, the conjugate acid, benzocaine hydrochloride is a salt in which is soluble in water and furthermore can be isolated from the organic mixture. When testing out the pH levels in benzocaine, the pH test strip was dark blue in color, indicating a pH level of around 5 to 7. When isolating benzoic acid, two milliliters of aqueous three molar sodium hydroxide was added, which deprotonates the carboxylic group in benzoic acid, forming its conjugate base, sodium benzoate. As with benzocaine hydrochloride, sodium benzoate is a water soluble ionic salt in the aqueous layer that can then be separated from the bottom organic layer containing the 9-fluorenone. The pH test strip was a vibrant red for benzoic acid, indicating a pH of 2. Now the 9-fluorenone is left, deionized water is added to remove any excess
The purpose of this experiment was to practice the functional group transformation procedure. The process of the experiment included the dehydration of 2-methylcyclohexanol in the presence of phosphoric acid and heat. The products that were formed from the reaction were 1-methylcyclohexene and 3-methylcyclohexene. The mass of the final product solution was 0.502g with a percent yield of 18.7% and a boiling point range of 84.5-98.5oC.
For the first part of this experiment, six dry test tubes were obtained and labeled accordingly to test the following halides: 2-chlorobutane, 2-bromobutane, 1-chlorobutane, 1-bromobutane, 2-chloro-2-methylpropane, and bromobenzene. To each of the six test tubes 2ml of 15% sodium iodide in acetone was added. 4 drops of the appropriate halide was added to the test tube labeled for that specific halide. After adding the halide, the test tube was then shaken to mix thoroughly. If a precipitate formed the time it took was recorded. Since none of the solutions formed a precipitate at room temperature after five minutes, the test tubes were placed inside of a hot bath at about 50°C. After one minute, the test tubes were taken out of the hot bath and allowed to cool. If any test tubes formed a precipitate, the time it took was recorded on a table.
In this experiment, the main objective was to synthesize a ketone from borneol via an oxidation reaction and secondly, to produce a secondary alcohol from camphor via a reduction reaction. Therefore, the hypothesis of this lab is that camphor will be produced in the oxidation reaction and isoborneol will be the product of the reduction reaction because of steric hindrance. For the oxidation step, a reflux will be done and then a microscale reflux for the reduction step. The products will be confirmed using Infrared spectroscopy, the chromic acid test, 2,4-DNP test and 13C NMR spectroscopy. The results of this
However, based on the data obtained in Table 1, Figure 1 shows that all of the chemical substances formed a precipitate, while the tertiary substrate 2-chloro-2-methylpropane formed a precipitate the fastest. This makes sense because as a rule in SN1 reactions, the more stable the carbocation is the faster the reaction will occur. Also, SN1 reactions will prefer tertiary substrates to secondary substrates and secondary substrates to primary substrates. The next substrates to form a precipitate were 2-bromobutane followed by 1-bromobutane. However, it was expected that 2-chlorobutane would form a precipitate before 1-bromobutane because 2-chlorobutane is a secondary substrate, and therefore has a more stable carbocation. The reason that this occurred is because bromine is a better leaving group than chlorine, which allows it to bind easier with the silver ion. The reactions that formed the heaviest precipitate were 2-bromobutane, 1-bromobutane, and 2-chloro-2-methylpropane. This is because these reactions occurred at a faster rate and therefore, generated more of a product than 2-chlorobutane and 1-chlorobutane, which only formed a precipitate upon cooling from the warm water bath.
The purposes of this experiment were to model a bimolecular nucleophilic substitution reaction between potassium hydroxide (KOH) with 1-bromopropane and determine whether it follows a second-order rate law mechanism. A rate constant of 0.0684 M-1 min-1 was obtained for this reaction at 45.1°C, which was determined through equilibrating the reaction and performing titrations of 0.390 M KOH with 0.1000 M hydrochloric acid (HCl). The activation energy calculated from class data was 50.188 kJ/mol, which deviated largely from the literature range value of 72.80–83.76 kJ/mol. It was concluded that the reaction was consistent with the predicted SN2 mechanism, based on the regression of a trendline.
The purpose of this experiment was to determine the pKa of the bromothymol blue (indicator) through absorption spectroscopy. Bromothymol blue being a monoprotic acid base indicator, displays different colors at different pH because of the differences in the ratio of the conjugated acid and base form. The fraction of conjugate acid and base was interpolated for the solutions through the acquired absorbance spectrum of the bromothymol blue at various pH. The rearranged form of Henderson Hasselbalch equation was graphed as a function of pH to determine the pKa of the indicator.
The guiding question of this ADI lab was, “What are the identities of the unknown compounds?” The goal of this lab was to understand the relationships between moles and molar mass to find the identity of unknown compounds. The mole can be used to measure small amounts of a substance or is used to convert from unit to unit using dimensional analysis. One mole is equivalent to the molar mass in grams of that substance. If you start with the moles of an unknown substance, multiply it by a given compound’s molar mass, and then divide it by however many moles are in the compound of your choice, you will get the mass of the compound. With that answer you can then compare with mass of the compound in the bag to determine its identity. We first started
Dispense .5 mL water into the already weighed conical vial, replace cap and face insert on its down side.
The purpose of this lab is to understand the process of eliminating an alkyl halide to form an alkene. The experiment is carried out by first converting the alcohol, 2-methy-2-butanol, into the alkyl halide of 2-chloro-2-methylbutane that will then be put through dehydrohalogenation that favors elimination reaction (E2) to create a mixture of 2-methyl-2-butene and 2-methyl-1-butene. A fractional distillation will be taken to purify the mixture and an additional gas chromatography will be done to further analyze the mixture composition. A bromide test will be done to determine the product of an alkene in the experiment.
An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water