Benzophenone Lab Report

The following equations and calculations are necessary in order to assess the results of the experiment. Calculation 1 utilizes Eq.1 to determine the mass and actual yield of triphenylmethanol on a watch glass. In all of the following calculations, “LR” refers to benzophenone, the limiting reagent of the experiment, and “Product” refers to triphenylmethanol.

There are various techniques to separate a mixture of compounds from each other. One of the commonly used way to isolate compounds from a mixture of two compounds is called extraction. This method of extracting two compounds from each other relies on the different solubility of the compounds in two different solvents.

The goal of the solubility experiment is to determine weather a substance is soluble or insoluble using various techniques. In part A of the experiment the solubility of different substances in different solvents will be investigated. To achieve the goal of part a 40 mg of benzophenone will be placed into test tubes. Each test tube will contain a different solvent and one will serve as a control. A spatula will be used to stir the contents in the test tube, once this step is complete it will be determined if the solid is soluble, insoluble, or partially soluble. Like part A, part B will also test the solubility, however the solubility of different alcohols will be tested to do this 1 mL of water or hexane will be added to each test tube

In this lab, liquid-liquid extraction was performed to isolate a mixture of benzocaine and benzoic acid. 2.0107 grams of the mixture was first weighed out for the trials. When HCl was added to the mixture for the first acid extraction of benzocaine, an emulsion formed during inversion and venting that prevented a defined separation of the two layers. 8 mL of water was therefore added before continuing the extraction. The addition of NaOH then turned the top aqueous layer basic, indicated by the pH strips that turned blue when tested. A vacuum filtration isolated 0.29 grams of benzocaine and a MelTemp apparatus measured the crystal’s melting point ranges to be 85.1C-87.4C. For the base extraction of benzoic acid, the aqueous layers were retrieved

The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in

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

In this experiment, 0.31 g (2.87 mmol) of 2-methylphenol was suspended in a 10 mL Erlenmeyer flask along with 1 mL of water and a stir bar. The flask was clamped onto a hotplate/stirrer and turned on so that the stir bar would turn freely. Based on the amount of 2-methylphenol, 0.957 mL (0.00287 mmol) NaOH was calculated and collected in a syringe. The NaOH was then added to the 2-methylphenol solution and allowed to mix completely. In another 10 mL Erlenmeyer flask, 0.34 g (2.92 mmol) of sodium chloroacetate was calculated based on the amount of 2-methylphenol and placed into the flask along with 1 mL of water. The sodium chloroacetate solution was mixed until dissolved. The sodium chloroacetate solution was poured into the 2-methylphenol and NaOH solution after it was fully dissolved using a microscale funnel.

After the initial mixture has refluxed, 9.11 grams of benzophenone was dissolved in 100 mL of anhydrous ether in a beaker and was then transferred into the separatory on the reflux apparatus. This solution was then added to the Grignard reagent at a drop wise rate while stirring. After the benzophenone was added, the mixture was then refluxed for 15 minutes on a heating mantle.

Dispense .5 mL water into the already weighed conical vial, replace cap and face insert on its down side.

An ideal solvent of 95% Ethanol was determined from the given solvents of water, 95% ethanol and hexane. Once the ideal solvent was determined a recovery of 27% or 0.54 grams of Benzoic Acid from 2.0 grams of crude Benzoic Acid mix using the 95% ethanol. The product was a white crystalline solid that produced a melting point range of 116-120 C compared to the actual range of 121-123 C meaning that a small amount of impurities are still present in the sample. The melting points of unknown M was 79-80 C showing it was Naphthalene, Unknown N was 100-107 C which shown to be catechol and Unknown O was 156-160 C showing it was Salicylic Acid.

In this experiment, the pKa, dissociation constant, of 2-naphthol was determined by measuring the UV-visible absorption spectra of solution of the acid at different pH values.

What was your null hypothesis? – As the concentration of benzoquinone increases the absorption will show no change.

First, a potato was removed from the refrigerator, where it had remained in order to slow down the benzoquinone reaction. The potato was then skinned to remove parts of the potato that were dark and could affect the spectrophotometer reading. The skinning of the potato also damaged the cells, initiating the release of catechol from within the cells. The potato was then placed in distilled water, a hypotonic solution, in order to further damage the plant cells so that they would release catechol from the cells and catecholase from the extracellular matrix. Next, the potato was chopped into smaller chunks to facilitate blending. The potato chunks were then placed into a blender that had been chilled in order to prevent the acceleration of the reaction. The chunks were then blended in three ten-second bursts, also to prevent prolonged use of the blender’s motor from quickening the reaction by heating the enzyme. If these conditions were not controlled, then the reaction would accelerate too quickly, which would directly affect the initial absorbance measurement since some benzoquinone would already have formed. Next, the blended potato was filtered through four layers of cheesecloth with

Based on Table 1 for experiment Part A which is the solubility of solid compounds, it resulted in the mixture of solution between benzophenone and water were insoluble. Water is highly polar meanwhile benzophenone is only slightly polar due to its carbon and oxygen is bonded by double bond. The fact that benzophenone is hydrocarbon, further addition of carbon atoms to the chain will decrease the polarity. The pi bonds in benzophenone also allow for greater Van Der Waals forces. Next, benzophenone and methanol were partially soluble because they have equivalent polarity. Benzophenone and methanol both possess an electronegative oxygen atom[2] that accounts for their related polarity and solubility. Benzophenone and hexane were partially insoluble too because hexane is a non-polar. Two non-polar compounds react with each other with the same polarity will not fully ionizes each other completely resulting to the partially soluble end result.

Practically insoluble in ethanol, ethanol (95%), ether and water, slightly soluble in benzene and warm ethanol (95%)