In this experiment, NaOH and diethyl ether are used as solvents. NaOH and diethyl ether must be immiscible with one another. They each must selectively attract the desired component from the solution being extracted. They should be easily separable from the solute being used. NaOH is a polar solvent and dissolves benzoic acid that has a high polarity, while diethyl ether is a nonpolar solvent and dissolves naphthalene that has a low polarity. The density determines the solvent position in the separatory funnel. Since diethyl ether is lighter (less dense) than water it stays on the top. Since both naphthalene and benzoic acid are soluble in diethyl ether they will not readily separate, that is why NaOH is added. When the polar solvent, NaOH, is added, benzoic acid reacts to form sodium benzoate and water because benzoic acid has a high polarity and is soluble in NaOH. …show more content…
NaOH molecules react with the benzoic acid molecules in the mixture and allow them to break a hydrogen bond (O-H bond) releasing H+ molecules while NaOH molecules break their bond into Na+ and OH- molecules.
Then the OH- and H+ molecules combine to form H2O water molecules and a sodium benzoate compound. Sodium benzoate then becomes insoluble in diethyl ether and soluble water. However, naphthalene does not react with the NaOH because it is not soluble in NaOH. Naphthalene and sodium benzoate differ in solubility and can therefore be separated into an aqueous layer and an organic layer. The diethyl ether is nonpolar and naphthalene has a low polarity so they are soluble together. The sodium benzoate is soluble in water. Diethyl ether is less dense than water so it stays on the top organic layer with naphthalene and sodium benzoate and water separate to the bottom aqueous layer of the separatory
funnel. To recover Naphthalene from the organic layer, a drying agent like sodium sulfate (Na2SO4) is used. The organic layer is wet because organic solvents like diethyl ether contain some suspended water. By swirling the Na2SO4 in the solution the surface area for contact between the solid & liquid phases increases and facilitates drying. The Na2SO4 molecules are not soluble so they do not dissolve in the mixture. Therefore, to separate the organic layer from the Na2SO4 gravity filtration is used. The Na2SO4 molecules remain on the filter paper leaving the naphthalene molecules and diethyl ether molecules together in the solution. Diethyl ether is evaporated using a steam cone. Naphthalene molecules crystalize at room temperature. To recover Benzoic acid, HCl is added to the cooled aqueous solution. HCl neutralizes the basic aqueous solution. Sodium benzoate is protonated to generate benzoic acid. Because the hydrochloric acid is insoluble in water, it appears as a precipitate. The solid precipitate is collected by vacuum filtration because it is insoluble and does not pass through the filter paper. The naphthalene and benzoic acid are analyzed using their weights and melting point temperatures. The efficiency of recovery of naphthalene and benzoic acid are calculated using the percent recovery equation. If the melting point range of the recovered naphthalene crystals and benzoic acid crystals are each about 1° C to 2° C apart then they are pure naphthalene and benzoic acid crystals.
The unknown bacterium that was handed out by the professor labeled “E19” was an irregular and raised shaped bacteria with a smooth texture and it had a white creamy color. The slant growth pattern was filiform and there was a turbid growth in the broth. After all the tests were complete and the results were compared the unknown bacterium was defined as Shigella sonnei. The results that narrowed it down the most were the gram stain, the lactose fermentation test, the citrate utilization test and the indole test. The results for each of the tests performed are listed in Table 1.1 below.
The goal of this two week lab was to examine the stereochemistry of the oxidation-reduction interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. The purpose of first week was to explore the oxidation of an alcohol to a ketone and see how the reduction of the ketone will affect the stereoselectivity. The purpose of first week is to oxidize the alcohol, 4-tert-butylcyclohexanol, to ketone just so that it can be reduced back into the alcohol to see how OH will react. The purpose of second week was to reduce 4-tert-butylcyclohexanol from first week and determine the effect of the product's diastereoselectivity by performing reduction procedures using sodium borohydride The chemicals for this lab are sodium hypochlorite, 4-tert-butylcyclohexanone
The isomerization procedure was done in order to create dimethyl fumarate from dimethyl maleate. Dimethyl maleate and dimethyl fumarate are cis and trans isomers, respectively. This procedure was done via a free radical mechanism using bromine. The analysis of carvones reaction was done in order to identify the smell and optical rotation of the carvone samples that were provided. The odor was determined by smelling the compound and the optical rotation was determined using a polarimeter.
Saturated sodium chloride solution, also known as brine solution, is used to wash the distillate mixture. The distillate mixture is the phosphoric acid the co-distilled with the product. The brine solution also removes most of the water from the 4-methylcyclohexane layer. When six drops of 4-methylcyclohexene were added with two
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 this lab 4-tert-butylcyclohexanone is reduced by sodium borohydride (NaBH4) to produce the cis and trans isomers of 4-tert-butylcyclohexanol. Since the starting material is a ketone, NaBH4 is strong enough to perform a reduction and lithium aluminum hydride is not needed. NaBH4 can attack the carbonyl group at an equatorial (cis) or axial (trans) position, making this reaction stereoselective. After the ketone is reduced by the metal-hydride, hydrochloric acid adds a proton to the negatively charged oxygen to make a hydroxyl group. The trans isomer is more abundant than the cis based on the results found in the experiment and the fact that the trans isomer is more stable; due to having the largest functional groups in equatorial positions.
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.
Benzyl bromide, an unknown nucleophile and sodium hydroxide was synthesized to form a benzyl ether product. This product was purified and analyzed to find the unknown in the compound. A condenser and heat reflux was used to prevent reagents from escaping. Then the solid product was vacuum filtered.
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.
As shown in Fig. 5, the final pH of the NaClO-NH3 solution after simultaneous removal are 5.4, 6.9, 7.2, 7.5, 8.5, 9.6, 10.7, 11.5 and 12.8 with respect to the initial pH of 5, 6, 7, 8, 9, 10, 11, 12 and 13, from which, an interesting law can be concluded as that if the initial pH is an acidic, the final pH is slightly increased; but if the initial pH is an alkaline, the final pH is declined. NaClO-NH3 is macromolecule compounds with a large inter surface area. It contains abundant functional groups such as hydroxyl (OH), carboxyl (COO), quinone, amino (–NH2), etc, which determines that NaClO-NH3 is a salt of strong base and weak acid, as well the ionization equilibrium and hydrolytic equilibrium would be complicated. When the pH of the NaClO-NH3 solution was acidic, the functional groups such as OH, COO and NH2- would react with H+ to generate the NH3 sediment, resulting in a decrease of inter surface area owing to the block and a great loss of NaClO-NH3, then the NOx removal as well as the duration time was decreased. As for the increase of the final pH in the acidic conditions, this was a result of the consumption of H+ by NaClO. The decrease of the
Benzoic acid does not dissolved in water unless the water is hot because the non polar hydrocarbon part outweighs the effect of polar –COOH part as non polar part was hydrophobic. So there was no hydrogen bonding took place and it was insoluble as the final result. Meanwhile, for ethyl 4-aminobenzoate not mixing with water due to greater chain of carbons in amino group makes it less polar than benzoic acid.
The objective of this experiment is to separate a liquid mixture of Ethyl Acetate and Toluene through the process of Fractional Distillation. It is also to determine the mixture composition and the physical properties of the two liquids. Fractional Distillation “is used to separate (purify) the different liquid components of a mixture.”1 This type of distillation differs from Simple Distillation in which the mixture being used “is composed largely of a single liquid component.”1 Both processes use the liquids boiling point for the purification. If a liquid is gathering and the temperature corresponds to the theoretical boiling point of the liquid, then that liquid is what is being collected. The theoretical plate is “Each section of the
The medication of paracetamol can be administered in various ways and they are sold in different formulations. The common dosage comes in tablets form of 500 mg, in dispersible fizzy tablets (500 mg) and oral suspensions. It can also be bought in capsules as a mixture with other API like caffeine and codeine.
Hypothesis If the type of yeast affects the rate of ethanol fermentation, then Non-expired Bread Machine will result in the fastest rate followed by Non-expired Quick Rise, Non-expired Traditional, and expired Quick Rise because Bread Machine has the smallest yeast granule size allowing it to dissolve faster, the pellet size of Quick Rise is smaller than Traditional suggesting that Traditional has a slower rate, and expired yeast loses its potency over time so it has the slowest rate of ethanol fermentation. Procedure The dependent variable is the rate of ethanol production. As sucrose reacts with the activated yeast, carbon dioxide gas will be produced. The dependent variable was measured by observing the amount of carbon dioxide gas produced.
Initially, NaCl was added in order to demulsify the distillate. Next is the addition of NaOH which solubilise the acidic eugenol into a phenoxide salt, leaving the other components that are neutral in nature. Addition of HCl to the base neutralizes the phenoxide to reform the original acidic form of eugenol. Hexane then solubilises eugenol from the aqueous layer. Anhydrous sodium sulphate was added in order to remove the remaining water in the organic