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.
Before beginning extraction, there are four main rules that should be considered while attempting to pick a solvent. Rule number one is that the extraction solvent and original solvent must be immiscible (do not mix) and form two individual layers. Water is denser so its bottom layer. The second rule is that the extraction solvent cannot irreversibly react with the compound you are trying to extract. Technically every reaction is reversible but the reaction here is easily reversed. If you can easily go backwards then the reaction is not a problem. But if it is a difficult reaction to go backwards, then you do not want that reaction to take place. The third rule is that the extraction solvent should be as specific to your compound as possible. One should yield every time you do an extraction since you lose and you want to limit the total number of separations you have to do to maximize your overall yield. The las...
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... 45.5%, and a melting point of 92-98oC. The purified amount of acid was 0.124g,a percent recovery of 37.6%, and a melting point of 154-165oC. The purified amount of base was 0.206g,a percent recovery of 62.4%, and a melting point of 130-141oC. The purified amount of neutral was 0.023g,a percent recovery of 6.97%, and a melting point of 94-99oC. Percent recovery is based on fact that we have a 1:1:1 ratio. The percent recovery was established by dividing the purified or crude amount by the initial amount times 100. Since the percent recovery was high before recrystallization and low after recrystallization, some product must had been lost during recrystallization. After comparing the melting points of the acid, base, and neutral compounds I think that the acid was Salicylic acid, the base was 2-methyl-4-nitroanaline and the neutral was 9-fluorene.
A: The reaction with water and vinegar was the most useful in this experiment. The physical properties were very self explanatory because the texture of the powders was all different expect icing sugar and cornstarch. Also the Ph levels were very similar of six and seven for corn starch and icing sugar respectively. d) Q: How confident do you feel about your identification of the
Every 5 minutes, a small amount of mixture was dissolved in acetone (0.5 mL) and was spotted onto a thin layer chromatography (TLC) plate, which contained an eluent mixture of ethyl acetate (2 mL) and hexanes (8 mL). The bezaldehyde disappearance was monitored under an ultraviolet (UV) light. Water (10 mL) was added after the reaction was complete, and vacuum filtrated with a Buchner funnel. Cold ethanol (5 mL) was added drop-by-drop to the dried solid and stirred at room temperature for about 10 minutes. Then, the solution was removed from the stirrer and place in an ice bath until recrystallization. The recrystallized product was dried under vacuum filtration and the 0.057 g (0.22 mmol, 43%) product was analyzed via FTIR and 1H NMR
The theoretical weight was 599.6 mg. This yields a percent yield of 3.7%. Table 1 also illustrates the experimental melting point of 99.3-102.1◦C. A melting point that has a range larger than 3◦C is indicative of impurities in the sample. A few possibilities of impurities could have been unreacted norbornene, and water. Evidence that supports that there was unreacted norbornene in the final sample was the fact that the product was a jelly-like structure. Norbornene by itself has a jelly-like structure. However, once norbornene reacted with the acid-catalyst (H2O2), then it should have changed the chemical structure of the molecule and once the solution was brought back down to room temperature, crystals should have formed. Since a jelly-like, or oil-like product was present at the end of the reaction, then this is indicative that there was unreacted norbornene in the sample. The second impurity that may have been present in the final product was water. Instead of adding 3 mL of sodium bicarbonate and then 3 mL of brine, 3 mL of brine was added first and then 3 mL of sodium bicarbonate was added. This experimental error caused excess aqueous solution to be added to the diethyl ether. Since excess water was added to the final product, about 4x the amount of anhydrous sodium sulfate was needed in order to remove the water from the product. This was another indication that there was too much water in
In the first section, the Synthesis of Aspirin, salicylic acid was weight to be 3.029 grams using mass by difference since it was weighed on a 150 milliliter beaker. 9.23 milliliters of the acetic anhydride and 14 drops of 85 percent phosphoric acid were added to this beaker. A Bunsen burner provided by the laboratory was then used to boil the just mixed combination by producing a flame underneath the positioned beaker on top, and then allowed to cool for several minutes after the Bunsen burner flame was terminated. Two quantities of distilled water were then added to this mixture to make it cool even further, which were 41 drops and 30 milliliters. After cooling for some time, this beaker was placed into an ice bath in order to start the crystallization process. A glass rod was used to scratch around the bottom and the sides to catch all of the crystallized Aspirin that was being formed during this whole process. Then, by using a Buchner funnel and filter paper, which was placed on top of the flask connected to a water aspirator with rubber tubing, the excess liquid was removed from the just scraped Aspirin crystals when the Aspirin was placed on the filter paper. Using a medicine dropper, the Aspirin crystals on the filter paper were washed with distilled water just so that any non-pure substances were removed from the crude product. When these crystals were then ultimately dry, they were placed on a watch glass and put into an oven for 30 minutes. Then they were weighed by mass by difference to yield 2.4667 grams of crude s...
The objective of this experiment was to perform extraction. This is a separation and purification technique, based on different solubility of compounds in immiscible solvent mixtures. Extraction is conducted by shaking the solution with the solvent, until two layers are formed. One layer can then be separated from the other. If the separation does not happen in one try, multiple attempts may be needed.
The purpose of the experiment was to use the method of simple distillation to separate hexane, heptane, and a mixture of the two compounds into three different samples. After separation, gas chromatography determined the proportions of the two volatile compounds in a given sample.
The general objective of this experiment was for the students to familiarise with the preparation of a simple organic compound and to purify the compound by recrystallization. This experiment allows the students to conduct synthesis of aspirin, reinforcing the skills of recrystallization and the technique of melting point determination.
Ensure gloves are worn at all times when handling strong acids and bases within the experiment of the preparation of benzocaine. 4-aminobenzoic acid (3.0g, 0.022 moles) was suspended into a dry round-bottomed flask (100cm3) followed by methylated sprits (20 cm3). Taking extra care the concentrated sulphuric acid of (3.0 cm3, 0.031 moles) was added. Immediately after the condenser was fitted on, and the components in the flask were swirled gently to mix components. It should be ensured that the reactants of the concentrated sulphuric acid and the 4-aminobenzoic acid were not clustered in the ground glass joint between the condenser itself and the flask. In order to heat the mixture to a boiling point, a heating mantle was used and then further left for gently refluxing for a constituent time of forty minutes. After the duration of the consistent forty minutes the rou...
The purpose of this experiment was to learn and preform an acid-base extraction technique to separate organic compounds successfully and obtaining amounts of each component in the mixture. In this experiment, the separation will be done by separatory funnel preforming on two liquids that are immiscible from two layers when added together. The individual components of Phensuprin (Acetylsalicylic acid, Acetanilide, and Sucrose as a filler) was separated based upon their solubility and reactivity, and the amount of each component in the mixture was obtained. Also, the purity of each component will be determined by the melting point of the component.
For this experiment we have to use physical methods to separate the reaction mixture from the liquid. The physical methods that were used are filtration and evaporation. Filtration is the separation of a solid from a liquid by passing the liquid through a porous material, such as filter paper. Evaporation is when you place the residue and the damp filter paper into a drying oven to draw moisture from it by heating it and leaving only the dry solid portion behind (Lab Guide pg. 33.).
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.
The solvent should be easily removed from the purified product, not react with the target substances, and should only dissolve the target substance near it’s boiling point, but none at freezing. A successful recrystallization uses minimum amount of solvent, and cools the solution slowly, if done to fast, many impurities will be left in the crystals. Using the correct solvent, in this case ice water and ethyl acetate, the impurities in the compound can be dissolved to obtain just the pure compound. A mixed solvent was used to control the solubility of the product. The product is soluble in ethanol an insoluble in water. Adding water reduced solubility and saturates the solution and then the crystals
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
After the some time, we filter it through a Büchner funnel before it is recrystallized and filtered again. The mass was recorded as it was dry. By adding sodium carbonate, we will now test whether what obtained is benzoic acid or not, because one can observe bobbles if it is an acid. After that we burn it to test if it is aromatic.
The first step is choosing a suitable recrystallization solvent. This step is crucial when it comes to executing a successful recrystallization experiment. Solubility comes into play when choosing a proper solvent. When choosing a solvent, its polarity must be similar to the compound that will be purified, in this case, the compound acetanilide. The principle of “like dissolves like” can be used to understand this simple concept.