Crystallization Is A Pure Substance

An Erlenmeyer flask was used to accommodate the largest volume of recrystallization solvent calculated and was cooled in an ice bath to increase the yield of crystals. The solid was collected by vacuum filtration and washed with a small amount of ice water. The product is then dried to a constant mass by use of an oven and weighed. A small amount of the unknown was compared to two samples of acetanilide and phenacetin for a melting point range to determine the identity. The temperature of the unknown was recorded when the first trace of liquid can be seen and when the unknown was completely liquid.

In experiment two, 1.48g of the unknown solid was recovered. From this mass, it was determined approximately 30mL of boiling water was needed for crystallization of acetanilide and about 121mL for phenacetin. Phenacetin would require more solvent because it is less

Moisten filter paper with a few drops of solvent and turn on water vacuum to fullest extent

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 product was then suspended in 2 ml of water with a stir rod in a 50 ml Erlenmeyer flask and heated to boiling. Water was added in one milliliter increments until all the product was dissolved (18 ml added total). The saturated solution was allowed to slowly cool, and gradual white crystal formation was observed. Recrystallized product was collected once more by suction filtration with the Hirsch funnel once crystallization ceased. Collected product dried on a watch glass for a week, weighed 0.14 g (1.2 mmol), and the melting point was 139°-141°

16) Heat some of the hexane to boiling and place the solid to be crystallized into an Erlenmeyer 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 solution is then cooled and recrystallization of the solute occurs. For a solvent pair to

The week after, a recrystallization was performed on the previous week’s crude product. The product ethereal solution was first heated on a steam bath until dry. During the heating, a beaker of methanol was collected and also placed on the steam bath. Once the product was dry, it was cooled to room temperature and then placed in an ice-water bath. The now boiling methanol was added to the crude crystals and a recrystallization was performed. Once completed, the now purified product was collected via Buchner vacuum filtration and stored in drawer to dry for a week. Afterwards, a melting point range of the purified product was obtained by using a Mel-temp apparatus. Lastly, an

Sulfanilamide, also referred to as sulfa, was a drug sold in powder and tablet form used to treat infections such as pneumonia, meningitis, and strep throat. In the 20th century, these bacterial infections could easily take the life of anyone. That is why sulfanilamide became so popular throughout the country. Sulfanilamide was invented by a German microbiologist, Gerhard Domagk. It was a red dye derivative that he had discovered that would cure the contagion. The drug was safe until a salesman from Bristol, Tennessee recommended that they produce a liquid form of the drug to make swallowing easier. The company’s head pharmacist and chemist was Harold Cole Watkins, he found out that sulfanilamide was soluble in diethylene glycol, commonly found

Marshall Berman’s take on modernity is presented in his book All That Is Solid Melts into Air whereby he focuses on its issues and the cultural attitudes and philosophies towards the modern condition. In doing so he shares his experiences of modernity post WWII in New York in the height of an economic boom and then more specifically of his childhood neighbourhood, the Bronx. In addition to expanded austerity, industrial and architectural development, the end of WWII proved to be a key period in world history and by extension the history of art. A talented group of artists emerged in result that had been influenced by an influx of established European artist who had fled to New York to escape fascist regimes in their homelands. More importantly these artists produced art that was at the heart of maelstrom Berman describes in regards to his experience of modernity. I aim to highlight the correlation between Berman’s experience of modernity and the emergence of a new American modernism. Modernity throughout this period was broken into two different compartments, hermetically sealed off from one another: "modernisation" in economics and politics, "modernism" in art, culture and sensibility. It’s through the lens of this dualism in which we recognise that both Berman and these artists try to make sense of the world around them by making their individual expressions that would re-conceptualise what it is to be modern in the twentieth century.

Minerals are naturally occurring, inorganic, solid, crystalline substances which have a fixed structure and chemical composition. Minerals are an important part of Geology, especially when studying Crystal and mineral growth. Understanding how crystals grow and the difference between slow and fast cooling rates is also important in Geology. Knowing the difference between cooling rates is important because cooling rate changes the texture of rocks and minerals. The purpose for the Crystal Growth experiment is to identify which Solubility and temperature produces larger crystals, and to simulate natural crystal growth. We will achieve the results we desire by conducting the experiment thoroughly and correctly, as well as correctly

Crystals were collected in a Buchner funnel, washed with alcohol, then ether, then transferred into a sample tube for storage.

Subsequently, 10mL of 3.5% H2O2 were added dropwise to the reaction mixture and was stirred for 20 minutes before heating to boiling at 80°C for 5 minutes. The reaction mixture was then taken off heat and allowed to cool undisturbed in an ice-bath for 30 minutes. Suction filtration was performed after to collect the crystals from the chilled solution The product was then washed with chilled 95% ethanol (2 x 15mL) and followed by diethyl ether (2 x 10mL). The crude product was then left to dry before recording the yield. 20mg of the crude product is then accurately weighed out and dissolved in deionized water in a 25mL volumetric flask. Deionized water was added to the volumetric flask to the mark and the UV-vis absorption spectrum of the crude product was recorded.