1. Name of experiment (1 pt): Aniline acetylation by means of the use of acetic anhydride and recrystallization of crude acetanilide for purification. 2. Purpose of experiment (2 pts): The purpose of the experiment was to acetylate aniline with the use of acetic anhydride and purify the crude acetanilide by recrystallization; in addition, determine the percent yield for acetanilide. 7. Interpret the obtained results (20 pts): The yield of the crude acetanilide was fair (98.45%). This was apparent from the melting point of the sample. The melting point of the crude acetanilide (116-123℃) had a fair comparison to the literature melting points (113-115℃(R1.). The yield of the recrystallized acetanilide was about half of the yield of the crude acetanilide. The recrystallized contained the key functional group. For instance, …show more content…
Answers to questions (attach to report) (15 pts): Question 1 What health and safety hazards are associated with aniline? (3 points) The health and safety hazards associated with aniline has a carcinogenic and mutagenic characteristic(R5.). It was classified as A3 by ACGIH; in addition, has mutagenic effects to the somatic cells(R5.). Not to mention, Aniline, perhaps, was toxic to blood, kidneys, and central nervous system(R5.) Lastly, nitrile gloves helps protect the experimenter; however, aniline will penetrates the gloves(R4.) Therefore, should be changed immediately(R4.). Question 2 The aniline starting material is fairly soluble in water / acetic acid, but the acetylated product is not. Explain this solubility observation in terms of exact, structural features in the two molecules.(4 points) The aniline is fairly soluble in water / acetic acid, while the acetylated product is not because the two hydrogen from the aniline are polar covalent resulting in hydrogen bonds. Acetanilide single hydrogen is bonded to nitrogen; therefore, is just a van der waal bond. This difference result in aniline being soluble, while acetanilide is
This excessive yield was resultant of the impurities within the product, where the solvents, particularly the dichloromethane, were not sufficiently removed from the product. In figure 3, the peak at 5.22 ppm with a normalised intensity of 1.00 evidenced the significant proportion of the dichloromethane in the product, and the peak at 0.88 ppm with a normalised intensity of 0.25 indicated some remaining hexane.4 The unreasonable yield was mostly attributed to these.
The goal of this lab is to synthesize maleic anhydride with polyethylene glycol of 200g/mol molecular weight (PEG 200) and 2,3-dimethyl-1,3-butadiene to get 4,5-dimethylcyclohexane-1,2-dicarboxylic acid anhydride and its diacid by using Diels-Alders reaction and hydrolysis, respectively. The crystals were determined using melting point determination and IR spectroscopy.
...le of the specific binding to metal molecular cations. 18-crown-6 and 15- crown ethers are used for the recrystallization of AN from non aqueous solvents. The crystals formed by this method showed decrease in hygroscopicity . T. Lee et al. used crown ethers to minimize the polymorphic transition near room temperature. The room temperature phase transition is minimized by forming 1:1 co-crystal of AN-benzo-18-crown-6 with a melting point of 125-129 0C. One disadvantage of this Phase stabilized AN is that it reduces the burn rate of the propellant. Organic compounds, those are having crystallographic structure close to AN crystalline structure are also used as phase stabilizers. N. Galavina et al. have been studied the phase stabilization of AN using the organic compounds containing plane unsaturated N-Heterocycles substituted by carbonyl, amine or imine groups.
The final product was p-methoxybenzoic acid and its identity was confirmed by melting point range of 183.6 – 184.8 oC, which closely corresponds to a standard of 185 oC. (Lehman). Since the melting point range is small, it confirms the purity of the product. Since the objective of the experiment was to determine the structure of the major component
The synthesis of aspirin was remodeled and revised for a small scale experiment. An esterification reaction from the combination of salicylic acid and acetic anhydride with the presence of an acid catalyst produced acetylsalicylic acid (aspirin) and acetate. Purification of the crude aspirin was done through a technique called crystallization, wherein both the single solvent and mixed solvent
The goal of the experiment “Extraction and Recrystallization” was to separate the unknown acid, base, and neutral compounds into individual components and to identify them by their melting point. Once the extraction takes place, the compounds are purified by recrystallization, which allows one to identify them by using their melting point. The extraction takes place using a separatory funnel and the original, organic solvent ethyl acetate. In the separatory funnel HCl was used to obtain the acidic extract and NaOH was used to get the basic extract. Throughout the extractions, the separatory funnel is inverted and shaken under the fume hood for 10 minutes to maximize the surface area contact. Since ethyl acetate has a high vapor pressure, the separatory funnel is also vented so that the vapor pressure does not build up.
Butane seemed to be a very stable and almost boring molecule. The atoms were just sharing electrons with no real net charge causing the molecule to be non-polar. The second molecule seems to have much more happening. The dipole on the Oxygen atom makes it seem much more complex. The main difference between these to is the fact that acetone is a liquid and butane is a gas causing acetones density to be substantially higher than butane. Both of these substances would float on top of water. The only main difference between the two molecules’ molecular formula is that acetone has an oxygen atom. Besides the one oxygen atom, they are essentially very similar atoms, but that atom completely changes its properties. That one atom managed to completely
In the beginning of our experiment of the synthesis of aspirin, we believed that if the catalyst increases in Ka value, i.e. acidity, and the conjugate base(s) do not react, then the percent yield of aspirin will increase when percent yield is a function of the acidity of the catalyst. While performing the experiment, we discovered that the sulfuric acid dissociated the most, which allowed the substance to have the greatest percent yield. This is due to the fact that the increased dissociation allows for more hydrogen protons to be donated.
It was clear that synthesis was of benzhydrol was taking place as the formation of the addition complex, which formed a white gunk, was present. Also, it was possible to tell the synthesis was occurring when the white gunk from the addition complex was consumed during the acid workup. During the extraction of the products there was two layers forming which also indicated that synthesis had occurred, and trace amount of white bits of product were found in the waste beaker which also indicated that synthesis occurred.
Nitrobenzene is used In the production of Aniline, which is used in the polymer industries to produce polyurethane
Identifying features and key components of unknown chemical mixtures are an essential part of chemistry. In many cases it is necessary to analyses and understand the chemical makeup of pharmaceuticals. Qualitative analysis is a method of testing a chemical mixture to determine its chemical makeup, such as its functional group. Identifying functional groups of an unknown compound are important, as it helps in understanding how a chemical acts under certain conditions, such as when changing physical states. Depending on the functional group, the boiling point will be higher or lower, due to the strong or weak intermolecular forces. In this experiment qualitative analysis is used to identify two unknown samples, a liquid and a solid (L21 and
The two compounds that showed benzoic acid as soluble was acetone and ethanol and benzoic acid did not appear to be soluble in hexanes or water. Acetone dissolved the benzoic acid at both room temperature and increased temperature, while benzoic acid in ethanol was only slightly soluble at room temperature and completely soluble at increased temperature. Acetone is a ketone, which is a carbon chain with an oxygen attached to it [1]. Ethanol is an alcohol; it is an ethyl group with a hydroxyl group attached to it [1]. Water is a covalent compound and hexanes is an alkane with a mixture of isomers of carbon-6. When comparing the functional groups and structures of the different solvents, the ethanol and acetone contain non-polar carbon chains with polar branches, while water is a completely polar molecule and hexanes contains no dipole moments. The non-polar carbon chains of the acetone and ethanol interact with the aromatic ring of the benzoic acid and dissolve the compound. The benzoic acid dissolved in acetone easier because the polar atom is in the center of the carbon chain rather than the side. The ethanol required heating because the increased kinetic energy of the solvent molecules broke apart the bonds of the solute easier. Ethanol would be the best for recrystallizing benzoic acid because you want a solvent in which the solute is insoluble at room temperature and soluble at high temperatures. The benzoic acid can be dissolved at high temperatures and slowly precipitated out to leave impurities in the solvent, resulting in pure benzoic
The catalytic process occurs at lower temperature anf offers higher selectivity but requires frequent regeneration of the catalyst. Then, the products are cooled and introduced into a pair of separators which separate the unreacted hydrogen. The unreacted hydrogen is compressed and recycle back to the feed and reactor. The products that leaving the separators are heated before introduced into a distillation column which the toluene is separated from the stream and recycle back to the...
The observed melting point for the purified acetanilide was 113.2 °C – 115.4 °C. In the end, the chosen solvent was water as the compound was completely dissolved in it while being heated but recrystallized once placed in an ice bath. Overall, the product was pure with the analytical data. The expected melting point is 114.3 °C.
2. Put 3 grams of salicylic acid and 4mL of acetic anhydride in 125mL conical flask.