CM1501 Expt 2 Essay

Melting Point Data Table Compound Aspirin Caffeine Salicylamide Actual MP (ºC) 93 - 98 260 - 262 96 - 102 Expected MP (ºC) 135 236 140 Percent Error (%) ~30% ~12% ~30%

Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.

Pankti Gandhi 9/26/14 Separation of Liquids by Simple Distillation and Analysis by Gas Chromatography Methods/Background: The purpose of this experiment was to separate two volatile components from a mixture due to the different chemical properties of each compound. The mixture used in this experiment was ethyl acetate (EtOAc) and butyl acetate (BuOAc). The mixture containing two liquids will be separated by a separation procedure known as distillation. This method relies on each compound having a distinct and separate boiling point.

To be able to complete this experiment various lab instruments were needed. This includes the use of beakers, test tubes, a metal spatula, wooden splints, and a Bunsen burner. The analysis begins with determining the physical traits of the compound. Then 0.15 grams of the unknown substance is mixed with 3 mL of distilled water to test

INTRODUCTION Hydrazones1-3 were reported to possess various biological activities. In the present communication we report the synthesis of new phenyl hydrazones. These hydrazones were synthesized by using different aromatic aldehydes which react with phenyl hydrazine in presence of alkali to undergo condensation by removal of one mole of water molecule. It is the simplest reaction to form reactive phenyl hydrazones. The synthesized compounds after purification were characterized by spectral methods viz.

By applying the general solubility rules listed below, the precipitate or lack of were then able to be analyzed to determine each substances identity after mixing on a spot plate. Given that specific compounds react differently when mixed with another substance, the precipitate, pH, and chemical equation of the reaction itself was utilized in determining the substance. Procedures such as the one conducted in this experiment are especially useful in determining which chemical is which, if it is unable to be deduced through pH, smell, or

Extraction is the process of selectively removing a compound of interest from a mixture using a solvent1. There is liquid-liquid extraction, which is based on the varying solubilities of different solutes in immiscible solvents2. There is also acid-base extraction, which is what was performed in this experiment. An acid-base extraction is a type of liquid-liquid extraction and is used to separate organic compounds from each other based on their acid-base properties3. The goal of this experiment was to extract and identify three unknown components from a mixture using extraction techniques based on acid-base properties, confirm the identities with a mixed melting point analysis, and compare the percent yields of each component to the expected

The same technique was used for the determination of the unknown; however, the solution used for each method was slightly different. Furthermore, the mobile phase in each method was of different concentration with the addition of ethylacetate in Solvent system A.

As the reagents were heated, a strong banana odor was present, and was especially strong during extraction. The condensed product was then cooled to lower the temperature, which allows for the C-O and O-H bonds in the products to form. Sodium bicarbonate was added to the acetic acid to form sodium acetate and carbonic acid, since the acetic acid was highly water soluble. The carbonic acid was then spontaneously broken into water and carbon dioxide molecules. The sodium acetate was extracted after each time the sodium bicarbonate was added for a total of four times.

The goal of the lab was to separate a neutral compound and an acid from an unknown mixture. The DCM (Dichloromethane) was added to create the organic layer. Both the neutral compound and acid were insoluble in water so aqueous NaOH was added. The acid would be deprotonated into an ion, which is soluble in water. Using the separatory funnel, the organic layer was separated from the aqueous layer. HCl was added so that the ion would protonate back into the acid and precipitate out of solution. Vacuum filtration via Buchner funnel was used to separate the acid (crystals) from the salt, NaCl. Na2SO4 was the drying agent used to remove any residual water from the organic layer. Gravity filtration helped separate the drying agent from the organic layer containing the neutral compound. The organic layer (DCM solvent) was boiled in order to separate the solvent from the neutral compound, which was in the form of crystals. Ethanol was heated up and added to the crystals of the neutral molecule which allowed the removal of impurities. The solution was placed in a hot water bath and the crystals of the neutral molecule precipitated out. The cool temperature helped crystallize the neutral compound into crystals. Finally, the neutral compound crystals were separated via vacuum filtration using a Buchner funnel. The acid and neutral compound and massed via an analytical balance so that the percent recovery can be calculated. Melting point (Mel-temp) was used to determine the

The three components of the unknown mixture were identified as Benzoic Acid, m-nitroaniline, and Naphthalene, as seen in Table 1. The melting point of the acidic component was 121.9℃-123.8℃ while the literature melting point of the suspected acid, Benzoic acid, is 121℃-122℃. The melting point of the basic component was 112.9℃-117.2℃ while the literature melting point for the suspected base m-nitroaniline was 111℃-114℃. The melting point for the neutral component was 77.9℃-82.8℃ while the literature melting point of the suspected compound Naphthalene is 79℃-82℃. The mixed melting point technique analytically confirmed the three identities of the components in the mixture because the melting point ranges for each component were extremely similar to the literature melting points of the suspected compounds.

Objective: The objective of this experiment is to use acid-base extraction techniques to separate a mixture of organic compounds based on acidity and/or basicity. After the three compounds are separated we will recover them into their salt forms and then purify them by recrystallization and identify them by their melting points.

The 4-nitrobenzoic acid product had a percent yield of 48.89%, showing a very high yield out of 50%. The melting point range was from 236-238°C, whereas the literature value is 237-240°C. The melting point of the product was very close to the literature value and also had a narrow range, indicating a pure product and therefore deeming recrystallization unnecessary. However, if the acid need to be purified, methanol would be used as the recrystallizing solvent.

Given the unknown compound, the goal was to find out exactly what the unknown compound is. By only having 5 grams of the unknown compound, it was necessary not to waste any of it if anything went wrong while conducting various tests. Using the lab equipment and techniques, the flame test, anion test, conductivity test, and the pH test should help figure out what the unknown compound is.

A couple of mixtures of unidentified organic compounds (a mixture of two liquids and another mixture of two solid compounds) were obtained, and the compounds of each mixture were then separated, isolated, and purified. The compounds of the liquid-liquid mixture were isolated by simple distillation, and the compounds in the mixture of solids were extracted by liquid-liquid extraction, and later purified through recrystallization. Physical properties –such as boiling points, melting points, and densities- were used to identify each isolated compound. After analysis, the first liquid was identified by a boiling range of 81.0°C-81.3°C and a density of 0.7882g/mL, and the second liquid was identified by a boiling range of 91.7°C-91.9°C and a density of 0.8578 g/mL. The crude solid products were purified and recrystallized, providing a white crystalline solid (MP = 35.2-37.8 °C) in 46.9% yield, and a white powdery solid (MP = 121.9 – 122.1 °C) in 2.40% yield.