Lab Report Puurification Of Acetanilide

The recrystallization technique utilizes the ability of a compound to dissolve within a hot solvent and produce a solution. As this solution cools, the solute reforms without impurities in a crystal lattice structure.1 For this to work properly, an appropriate solution that will not dissolve the solute at low temperatures, but will at high temperatures, must be used.1 There is no single solvent that will work well for every solute’s recrystallization; different solvents are better suited for some solutes than others.2 Some impurities that do not dissolve within the solvent can be filtered out while the solution is still hot, while other impurities that readily dissolve within the solvent shouldn’t recrystallize with the pure substance (as they are not concentrated enough to

The product was placed in a Craig tube and several drops of hot (100°C) solvent (50% water, 50% methanol, by volume) was added and heated until all of the crystals dissolved. The Craig tube was plugged and set in an Erlenmeyer flask to cool. Crystallization was induced once the mixture was at room temperature by scratching the inner wall of the tube. It was then placed into an ice bath for ten minutes until crystallization was complete. The tube was then

The first step is the separation of the solid crystals back into separate ions, a positive ammonium ion and a negative nitrate ion. The break these ionic bonds requires a lot of energy which means heat must be taken from the surrounding water. The second step the water molecules, which are H2O, are attracted to the ions and attach themselves to the ions. The second step actually causes heat to be produced to the surrounding liquid mixture. .Even

The goal of this experiment was to synthesize aspirin. In this experiment aspirin, also known as acetylsalicylic acid, was synthesized from salicylic acid and acetic anhydride. In the reaction the hydroxyl group on the benzene ring in salicylic acid reacted with acetic anhydride to form an ester functional group. This method of forming acetylsalicylic acid is an esterification reaction. Since this esterification reaction is not spontaneous, sulfuric acid was used as a catalyst to initiate the reaction. After the reaction was complete some unreacted acetic anhydride and salicylic acid was still be present in the solution as well as some sulfuric acid, aspirin, and acetic acid. Crystallization, which uses the principle of

21) After all of the solid dissolves, move the flask from the hot plate and allow it cool to room temperature. After a while, crystals should appear in the flask.

Method: Distillation is based on the fact that the matter can exist in three phases - - solid, liquid and gas. As the temperature of a pure substance is increased, it passes through these phases, making a transition at a specific temperature from solid to liquid (melting point--mp) and then at a higher temperature from liquid to gas (boiling point--bp). Distillation involves evaporating a liquid into a gas phase, then condensing the gas back into a liquid and collecting the liquid in a clean receiver. Substances that have a higher boiling point than the desired material will not distill at the

The experiment contains two procedures: the solubility tests, and macroscale recrystallization of chosen solutes and solvent. The solubility tests were performed with all the solutes, which were phthalic acid, naphthalene, anthracene, benzoic acid, and resorcinol. The three solvents were water, methanol, and acetic acid. Solubility tests were carried out at both low and high temperature conditions, depending on the substance. The most efficient pair was acetic acid and anthracene, which was chosen for the second part of the experiment.

The solution is then cooled and recrystallization of the solute occurs. For a solvent pair to

11. The mixture was poured into a 150mL pot and heated until all the aqueous solution evaporated, leaving acetanilide in the pot. 12. The mass of the pot before and after the reaction was recorded. 13.

iii. Rinsing the recrystallized material on the filter with room temperature solvent could have negative effects on the results of the recrystallization because even room temperature solvent can dissolve the solute (recrystallized material) It is always necessary to use cold solvent as it cannot dissolve the solute.

The experiment recrystallization was divided into two parts. In the first part, the purpose was to find the solubility of the four compounds, anthracite, resorcinol, benzoic acid, and 4-amino-1-napthalenesulfuric acid using three different solvents, water, toluene, and n hexane. Further, Phthalic acid and benzoin were recrystallized.

An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water

Crystallization can be divided into two processes, nucleation and crystal growth. Nucleation is the initiation of a phase change in a small region, such as the formation of a solid crystal from a liquid solution.It is a process in which a minimum number of atoms,ions or molecules join together to give a stable nuclei.The rate of nucleation is believed to increase with increasing relative supersaturation.

The second method involved aliquotting 10µl of each of the reconstituted materials into cryovials (in triplicate) and adding the requisite 1490µl Premier diluent before storing upright and frozen at -20oC.

Lyophilization is the process of removing water and/or solvents from a product by the method of sublimation and desorption. By this method, no biological or chemical reaction can happen. The process involved in lyophilization are described as follows: