Recrystalization PT 1 Essay

Recrystalization PT 1 Essay Recrystalization PT 1 Essay Introduction The purpose of this lab is to purify four solid compounds: resorcinol, anthracene, benzoic acid, and 4-amino 1-napthalenslfonic acid, sodium salt. This is achieved by using water, toluene, and ligroin as solvents. The solubility of the compounds in said solvents must be tested at low and high temperatures. Then, the solution can be recrystallized. Finally, the product is filtered, using either a Pasteur pipette or suction filtration. Experiment In the lab, the sand bath was turned on to 40%. A rough estimate of 10 mg of each solid sample is placed in a test tube. This solid was transferred to a test tube sing a disposable pipet. A boiling stick was placed in a reaction tube. Then, 0.25 mL of the solvent was dropped in the tube and flicked. For the compounds that had a solid dissolve at room temperature, nothing else has to be done. When some dissolved, then an extra 0.25 mL is added and reheated. If it is insoluble, then it was attempted to be heated, but will not dissolve. The dissolved compounds must be cooled to see the crystallization. All four compounds were tested in three solvents (water, hexanes, and toluene). Phthalic Acid was weighed to be 54 mg. 0.33 mL of water was supposed to be used, but 0.5 mL was necessary for the solid to dissolve. A boiling stick was placed in the test tube and the solution was brought to a boil. The water was added drop wise until the last solid piece dissolved. The test tube cooled undi sturbed. Once it reached room temperature, it was further cooled in an ice bath. When the crystallization was completed, the crystals were stirred with a pipette. Air was expelled from the bottom and solution was drawn up. The test tube was tapped on a soft surface and repeated if any solvent remained. The curved end of the spatula was used to scoop up the remaining solid. The crystals were left overnight before weighing. The recrystallization of benzoin began with weighing 53 mg of the compound. Ten drops of ethanol was added, then boiled for half a minute. Later, more drops were added until all of the solid was dissolved. The approximate amount of solution in the tube was 0.70 mL. The solution was allowed to cool to room temperature, then placed in an ice bath to cool further. The filter flask was clamped to the ring stand using a 3-pronged holder. The plastic Hirsch funnel was placed into the flask. The filter paper was weighed and placed inside the funnel. The vacuum tbing was c onnected to the side-arm of the flask. A few drops of fresh solvent was added to the funnel. The crystal was rinsed with fresh, chilled solvent. The seal was broken and ten drops of ethanol-water mixture was added, followed by an immediate continuation of the vacuum filtration. The crystals were let to dry overnight before weighing. The contents of the tubes was disposed of in waste containers. Any glassware needed for immediate use had acetone added to clean quickly. Results Phthalic Acid 0.485 g 0.485g/0.54g * 100 = 89.8% recovery of Phthalic Acid Benzoin 0.250 g 0.250g/0.53g * 100 = 47.2 % recovery of Benzoin Anthracene Cold (Room Temp.) Hot (Boiling) Water Insoluble Insoluble Toluene Insoluble Soluble Hexanes Insoluble Slightly Soluble Benzoic Acid Cold (Room Temp.) Hot (Boiling) Water Insoluble Slightly soluble(but pasty texture) Toluene Insoluble Soluble Hexanes Slightly Soluble Soluble Resorcinol Cold (Room Temp.) Hot (Boiling) Water Soluble Toluene Insoluble Soluble Hexanes Insoluble Slightly Soluble 4-amino 1-napthalenslfonic acid, sodium salt Cold (Room Temp.) Hot (Boiling) Water Slightly Soluble Soluble (didn’t dissolve back) Toluene Insoluble Insoluble Hexanes Insoluble Slightly Soluble (ppt. out quick) Discussion The Anthracene

Le Chateliers Principle in Chemistry

Le Chatelier's Principle in Chemistry Le Chatelier†²s Principle is the principle when a stress is applied to a chemical system at equilibrium, the equilibrium will shift to relieve the stress. In other words, it can be used to predict the direction of a chemical reaction in response to a change in conditions of temperature, concentration, volume, or pressure. While Le Chateliers principle can be used to predict the response to a change in equilibrium, it does not explain (at a molecular level), why the system responds as it does. Chatalier's Principle or the Equilibrium Law The principle is named for Henry Louis Le Chatelier. Le Chatelier and Karl Ferdinand Braun independently proposed the principle, which is also known as Chateliers principle or the equilibrium law. The law may be stated: When a system at equilibrium is subjected to a change in temperature, volume, concentration, or pressure, the system readjusts to partially counter the effect of the change, resulting in a new equilibrium. While chemical equations are typically written with reactants on the left, an arrow pointing from left to right, and products on the right, the reality is that a chemical reaction is at equilibrium. In other words, a reaction may proceed in both the forward and backward direction or be reversible. At equilibrium, both the forward and back reactions occur. One may proceed much more quickly than the other. In addition to chemistry, the principle also applies, in slightly different forms, to the fields of pharmacology and economics. How to Use Le Chatelier's Principle in Chemistry Concentration: An increase in the amount of reactants (their concentration) will shift the equilibrium to produce more products (product-favored). Increasing the number of products will shift the reaction to make more reactants (reactant-favored). Decreasing reactants favors reactants. Decreasing product favors products. Temperature: Temperature may be added to a system either externally or as a result of the chemical reaction. If a chemical reaction is exothermic (ΔH  is negative or heat is released), heat is considered a product of the reaction. If the reaction is endothermic (ΔH  is positive or heat is absorbed), heat is considered a reactant. So, increasing or decreasing temperature can be considered the same as increasing or decreasing the concentration of reactants or products. In the temperature is increased, the heat of the system increases, causing the equilibrium to shift to the left (reactants). If the temperature is decreased, the equilibrium shifts to the right (products). In other words, the system compensates for the reduction in temperature by favoring the reaction that generates heat. Pressure/Volume: Pressure and volume can change if one or more of the participants in a chemical reaction is a gas. Changing the partial pressure or volume of a gas acts the same as changing its concentration. If the volume of gas increases, pressure decreases (and vice versa). If the pressure or volume increase, the reaction shifts toward the side with lower pressure. If the pressure is increased or volume decreases, equilibrium shifts toward the higher pressure side of the equation. Note, however, that adding an inert gas (e.g., argon or neon) increases the overall pressure of the system, yet does not change the partial pressure of the reactants or products, so no equilibrium shift occurs.

Business Report of Coca-cola Coursework Example | Topics and Well Written Essays - 2500 words

Business Report of Coca-cola - Coursework Example On the other hand, the internal functions of environmental reporting include to establish or revise or review existing environmental policies, objectives, and programs of organizations and to motivate the management and employees in organizations so as to encourage environmental activities of them. There is a general consensus that excellent environment report should explicitly acknowledge and explain environmental impacts that arise as a result of organizations operations and products and should further demonstrate the commitment of organizations to reduce such environmental impacts by publicly disclosing its policies, targets and long-term objectives (ACCA, 2010). This paper explores environmental reporting in companies with Coca Cola as a case study. Environmental Reporting in Coca Cola Company Coca Cola Company is the largest beverage company in the world and it responsible for the production of more than 500 brands of beverages that refreshes its consumers. Coca-Cola Company pro duces sparkling beverages, ready-to-drink coffees, juices ant juice drinks. The most popular and major beverage brands that are produced by the Coca Cola company include Coca-Cola, diet coke, fanta, sprite, coca-cola zero, vitamin water, powerade, minute maid, simply, Georgia and del valle (Coca-Cola-Enterprises., 2012). Coca Cola Company currently operates in more than 200 countries and has established markets across the world. The increasing sensitivity and awareness towards social and environmental issues and the concerns of stakeholders has prompted companies to enhance their images by endeavoring to become better corporate citizens and Coca Cola has not been left out in this trend. It is evident that Coca Cola Company has a wide array of stakeholders who have influence and interests on the company due to its global presence inn terms of market share and operations. Since the stakeholders are diverse and posses different interests and influence, any engagement and interactions t hat Coca Cola Company has with the stakeholders has the potential of shaping its current market share and future investment. The role that such stakeholders play has prompted Coca Cola Company to adopt environmental sustainability reporting as part of its strategic management goals. Another key feature that has caused Coca Cola Company to adopt environmental reporting is the economic, social and environmental impacts that are associated with the operations of the firm (Cross & Miller, 2009). There exist direct and indirect environmental impacts that originate from the operation of Coca Cola Company business. Examples of direct environmental impacts that are associated with Coca Cola business include greenhouse house gas emissions that emanate from the manufacturing site and distribution chain, emissions from cool drinks equipment, consumption of water and waste disposal from manufacturing site (Coca-Cola Company, 2011). The type of environmental reporting Company adopts is based on the guidelines that are given by the United Nations Global Compact framework. Environmental Reporting Strategies and Systems