...------------------------------------------------- Water purification From Wikipedia, the free encyclopedia This article is about large scale, municipal water purification. For portable/emergency water purification, see portable water purification. For industrial water purification, see deionized water. For distilled water, see distilled water. For the treatment of sewage see sewage treatment Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from contaminated water. The goal is to produce water fit for a specific purpose. Most water is purified for human consumption (drinking water), but water purification may also be designed for a variety of other purposes, including meeting the requirements of medical, pharmacological, chemical and industrial applications. In general the methods used include physical processes such as filtration,sedimentation, and distillation, biological processes such as slow sand filters or biologically active carbon, chemical processes such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light. The purification process of water may reduce the concentration of particulate matter including suspended particles, parasites, bacteria,algae, viruses, fungi; and a range of dissolved and particulate material derived from the surfaces that water may have made contact with after falling as rain. The standards for drinking water quality are typically...
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...nations, a growing number of contaminates are entering in fresh water; from traditional compounds to micro/nano pollutants. Common...
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...Synthesis of Acetanilide and Purification by Recrystallization Par, B., Ramos, S., Reynaldo, H., Roque, P., Servidad, Y., and Soriente, P. 2D-Pharmacy, Group No. 7, Department of Pharmacy, Faculty of Pharmacy, University of Santo Tomas, España Boulevard, 1015 Manila, Philippines Abstract Recrystallization is the primary method of purification used to isolate organic compounds in a supersaturated solution by the difference of solubility at different temperature that results to the separation of the compound from the solution. The purpose of this experiment is to synthesize acetanilide by the acetylation of aniline and to obtain pure acetanilide by purification of the collected crude acetanilide by crystallization. The recrystallizing solvent was chosen among ethanol, water and hexane. The acetanilide was synthesized and formed by acetylation of aniline and acetic anhydride, and it was then cooled to hasten the formation of crystals. After cooling, the mixture was filtered and dried to obtain the crude acetanilide. The crude acetanilide and the chosen recrystallizing solvent was mixed and heated in the water bath until the solid dissolved. The solution was filtered while hot and its filtrate was cooled in an ice bath. The filtrate was then filtered to collect the crystal residue formed. The crystals were washed with distilled water and allowed to dry to obtain the pure acetanilide. The weight of pure acetanilide was measured and the melting point of the pure acetanilide...
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...The purpose of this lab was to purify crude product by column chromatography. The crude product to be purified in this lab was acetylferrocene contaminated with ferrocene. Column chromatography is a technique that utilizes the liquid solid absorption method. This technique has the advantage by isolating more of the product that need to be analyzed. In Column Chromatography the mixture that is being examined, mixture of our product or compound is dissolved in small amount solvent that is then placed on top of the column. Finely packed solid absorbent (silica gel) act as the stationary phase. In order for the mixture to move down the column a eluting solvent (mobile phase) is placed. The separation of the organic compounds depends on how...
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...mechanical-chemical, mechanical-biological and chemical-biological. The shipboard sewage treatment plant should be small, simple, and reliable and have moderate running costs. The treatment plant should function well in all waste water concentrations and during flow peaks. The plant should be also easy to maintain and operate, and fulfill current purification requirements. The plant operation highly depends on the technical personnel and the sewage being cleaned. − BOD5: 50 mg/l − TSS: 100 mg/l (shipboard test) − Faecal coliforms: 250 cfu/100 ml. Waste water pre-treatment Wastewater pre-treatment protects the other phases of the purification process. Sewage contains a lot of solid waste and grease that may cause problems in the later stages of the process. The pre-treatment process reduces the amount of solids in the waste water. Effective wastewater pre-treatment also reduces the need for oxidation. The pre-treatment is mechanical and consists of sieving and sedimentation units. The large particles pass through a shredding pump before sieving. Oxidation The mechanical filtering results in a maximum of 50% reduction in organic load. The remaining organic...
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...Water and water purification A plentiful supply of suitable water is essential for a dyeing and bleaching plant. Before modern methods of water purification were purification were available, the textile industries tended to congregate in areas where the natural water supply was plentiful and sufficiently pure. Water with a high degree of purity is rarely obtainable from natural sources. A knowledge of he impurities which will probably be present and how to remove them is, therefore, desirable. Supplies of water may be classified as follows: i) rain water ii) surface water, which consists of rain which has collected into streams, rivers, or lakes; iii) subsoil water, which has percolated a small distance into the ground. It is collected from shallow wells or surface springs; and iv) deep well waters, which have usually percolated through several strata. ➢ Rain water:- Rain, collected immediately after propitiation, is the purest of all natural waters. It may contain traces of gases dissolved out of the atmosphere, and possibly an almost infinitely small amount of finely divided solid matter derived from the air. In the neighborhood of towns rain may collect dissolved or suspended impurities such as soot, traces of sulphur dioxide, or sulphuric acid, and other by-products of industrialization. Rain water from such sources is improved by filtration through a bed of sand. Although the collection of rain for industrial purposes dose not warrant...
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... Recrystallization PURIFICATION AND CHARACTERIZATION OF ACETANILIDE Abstract This experiment dealt with purification and analysis techniques like recrystallization, hot filtration and melting point measurement. Recrystallization and hot filtration use relative solubility of impurities and acetanilide (desired substance) to purify the crude form and melting point analysis is used along with weight measurement to examine the purity and quantity of yield. Introduction In the experiment, we used the hot filtration and recrystallization to separate pure acetanilide from its crude form. The purification of such chemicals is an especially important technique as it can be applied cheaply to medical drugs and remove the impurities in/on them which among other things increase toxicity (sideeffects) and reduce the efficiency of the drug. Other purification procedures such as extraction, sublimation and chromatography can also be used, but recrystallizing the resulting substance after these will yield a higher level of purity.The processes used rely upon the relative solubilities of the impurities in crude acetanilide with regards to each other and the pure form of the chemical. Hot Vacuum filtration – This process involves the filtering out of an insoluble substance (impurity or desired compound) that hasn't dissolved in ...
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...Name: Srikant Tulsi Reg # 10/0705/0497 Experiment # 4 Date: 5/11/2014 Partners: Shefali Seecharran Pride Ade-Thomas Claude Fraser Title: Synthesis of 9,10-Dihydroanthracene-9,10-Endo-α,β – Succinic Anhydride Reactions: Reaction Mechanism Physical Properties Table: Chemical | Formula | M.W (g/mol) | Quantity (g or ml) | Amount( moles) | Molar Equivalent | M.P(OC) | B.P (OC) | Density\(g/cm3) | Yield (g) | % yield | Anthracene | C14H10 | 178.23 | 2.018 g | 0.0113 | 1 | 215 | 339 | 1.28 | | | Xylene | C8H10 | 106.16 | 2.5 ml | 0.0022 | 1 | -47.4 | 138.5 | 0.864 | | | Maleic Anhydride | C4H2 O3 | 98.06 | 1.001 g | 0.0102 | 1 | 52.8 | 202 | 1.480 | | | Hexane | C6H14 | 86.18 | - | - | | -96 | 68 | 0.655 | | | DCM | C10Cl2 | 84.93 | - | - | | -96.7 | 39.6 | 1.327 | | | Ethyl Acetate | C4H8O2 | 88.11 | - | - | | -83.6 | 77 | 0.897 | | | 9,10-Dihydroanthracene-9,10-Endo-α,β – Succinic Anhydride | C18H12O3 | 276.29 | - | - | | 262-264 | | | 2.326 | 82.43 | Calculations: * Calculating the number of moles of Anthracene Mass of Anthracene Used is 2.018 g Molar Mass is 178.23 g/mol Number of moles = MassMolar mass = 2.018 g 178.23gmol = 0.0113 moles * Calculating the number...
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...Name: Srikant Tulsi Reg # 10/0705/0497 Experiment # 4 Date: 5/11/2014 Partners: Shefali Seecharran Pride Ade-Thomas Claude Fraser Title: Synthesis of 9,10-Dihydroanthracene-9,10-Endo-α,β – Succinic Anhydride Reactions: Reaction Mechanism Physical Properties Table: Chemical | Formula | M.W (g/mol) | Quantity (g or ml) | Amount( moles) | Molar Equivalent | M.P(OC) | B.P (OC) | Density\(g/cm3) | Yield (g) | % yield | Anthracene | C14H10 | 178.23 | 2.018 g | 0.0113 | 1 | 215 | 339 | 1.28 | | | Xylene | C8H10 | 106.16 | 2.5 ml | 0.0022 | 1 | -47.4 | 138.5 | 0.864 | | | Maleic Anhydride | C4H2 O3 | 98.06 | 1.001 g | 0.0102 | 1 | 52.8 | 202 | 1.480 | | | Hexane | C6H14 | 86.18 | - | - | | -96 | 68 | 0.655 | | | DCM | C10Cl2 | 84.93 | - | - | | -96.7 | 39.6 | 1.327 | | | Ethyl Acetate | C4H8O2 | 88.11 | - | - | | -83.6 | 77 | 0.897 | | | 9,10-Dihydroanthracene-9,10-Endo-α,β – Succinic Anhydride | C18H12O3 | 276.29 | - | - | | 262-264 | | | 2.326 | 82.43 | Calculations: * Calculating the number of moles of Anthracene Mass of Anthracene Used is 2.018 g Molar Mass is 178.23 g/mol Number of moles = MassMolar mass = 2.018 g 178.23gmol = 0.0113 moles * Calculating the number...
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...In this experiment, sublimation was used to purify solid mixtures. The compound used to undergo purification is impure benzoic acid. The product obtained after the heating process is called the sublimate in the form of crystals. The weight of the impure benzoic acid gave a lot of difference from the sublimate obtained from 5.0014 g to 0.3213 g, respectively. Thus, the measured sublimate showed the low percentage recovery of the said compound. The sublimate was then subjected to melting point determination together with the pure benzoic acid through the oil bath. The oil bath was used since it is able to measure temperatures even those beyond 100 °C and are highly recommendable for compounds which have higher boiling points. As it was seen in the results for the melting point determination, the sublimate started to melt at 116 °C and stopped melting at 120 °C while the pure benzoic acid started to melt at 120 °C and ended at 121 °C. The temperatures measured indicated that the pure benzoic acid has a higher vapour pressure than the sublimate. INTRODUCTION Sublimation is the direct vaporization of a solid by heating without passing through the liquid state. [1] The process of sublimation in this experiment is used to purify the impure benzoic acid. The impurities in the benzoic acid have amino compounds that are present in a larger extent and must be removed because of phenyl and benzyl compounds that seriously affect the product.[3] This process occurs if the vapour pressure...
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...CHEMISTRY CHEMISTRY (CLASSES XI–XII) Rationale Higher Secondary Stage is the most crucial stage of school education because at this stage specialised discipline based, content oriented courses are introduced. Students reach this stage after 10 years of general education and opt for Chemistry with a purpose of mostly for pursuing their career in basic sciences or professional courses like medicines, engineering, technology and studying courses in applied areas of science and technology at tertiary level. Therefore, at this stage, there is a need to provide learners with sufficient conceptual background of Chemistry, which will make them competent to meet the challenges of academic and professional courses after the higher secondary stage. National Curriculum Framework for School Education – 2005 recommends a disciplinary approach with appropriate rigour and depth with the care that syllabus is not heavy and at the same time it is comparable to the international level. It emphasizes a coherent focus on important ideas within the discipline that are properly sequenced to optimize learning. It recommends that theoretical component of Higher Secondary Science should emphasize on problem solving methods and the awareness of Syllabus for Secondary and Higher Secondary Levels 22 historical development of key concepts of science be judiciously integrated into content. The present exercise of syllabus development in Chemistry at Higher Secondary Stage is based on this framework...
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...CHEMICAL CONVERSIONS Acylation Acylation (rarely, but more formally: alkanoylation) is the process of adding an acyl group to a compound. The compound providing the acyl group is called the acylating agent. These are used to form aryl ketones. Because they form a strong electrophile when treated with some metal catalysts, acyl halides are commonly used as acylating agents. For example, Friedel-Crafts acylation uses acetyl chloride (ethanoyl chloride), CH3COCl, as the agent and aluminum chloride (AlCl 3) as a catalyst to add an ethanoyl(acetyl) group to benzene: The mechanism of this reaction is electrophilic substitution. Hydrolysis While solvolysis often refers to an organic chemistry context, hydrolysis is very common in inorganic chemistry, where aqua complexes of metal ions react with solvent molecules due to the Lewis acidity of the metal center. For example, aqueous solutions of aluminium chloride are acidic due to the aqua-aluminium complex losing protons to water molecules, giving hydronium ions which lowers the pH. In organic chemistry, hydrolysis reactions often give two fragments from an initial substrate. For example, the hydrolysis of amides give carboxylic acids and amines; the hydrolysis of esters give alcohols and carboxylic acids. Alcoholysis An example of a solvolysis reaction is the reaction of a triglyceride with a simple alcohol such as methanol or ethanol to give the methyl or ethyl esters of the fatty acid, as well as glycerol. This reaction is...
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...Uses of Lithium Ceramics and glass Lithium oxide is a widely used flux for processing silica, reducing the melting point and viscosity of the material and leading to glazes of improved physical properties including low coefficients for thermal expansion.[83] Lithium oxides are a component of ovenware. Worldwide, this is the single largest use for lithium compounds.[82] Lithium carbonate (Li2CO3) is generally used in this application: upon heating it converts to the oxide.[84] Electrical and electronics In the later years of the 20th century, owing to its high electrochemical potential, lithium became an important component of the electrolyte and of one of the electrodes in batteries. Because of its low atomic mass, it has a high charge- and power-to-weight ratio. A typical lithium-ion battery can generate approximately 3 volts per cell, compared with 2.1 volts for lead-acid or 1.5 volts for zinc-carbon cells. Lithium-ion batteries, which are rechargeable and have a high energy density, should not be confused with lithium batteries, which aredisposable (primary) batteries with lithium or its compounds as the anode.[85][86] Other rechargeable batteries that use lithium include the lithium-ion polymer battery, lithium iron phosphate battery, and thenanowire battery. Lubricating greases The third most common use of lithium is in greases. Lithium hydroxide is a strong base and, when heated with a fat, produces a soap made of lithium stearate. Lithium soap has the ability to thicken oils...
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...esophagus. Aspirin can be synthesized by the reaction of Salicylic acid with acetic anhydride and 85% Phosphoric acid as the catalyst when heated in a water bath at 90°C. The formation of white crystals after scratching the solution and after cooling in an ice bath indicates the presence of the product formed after the reaction. Solubility test with water and toluene, melting point determination by oil bath and thin layer chromatography by different kinds of solvents such as 10%EA in DCM, 30%EA in DCM, 10% hexane in EA and 10% DCM in Acetone are confirmatory tests for the presence of Acetylsalicylic acid. Thin layer chromatography is an analytical technique to determine the identity of the substances and to determine the effectiveness of purification. Keywords: Acetylsalicylic acid, solubility test, melting point, thin layer chromatography Introduction Acetylsalicylic acid, commonly called “aspirin” is an analgesic, an antipyretic and an anti-inflammatory agent. Aspirin was synthesized by Charles Gerdhadt but was patented to the Bayer Company by Felix Hoffman. It was synthesized to alter the corrosive nature of salicylic acid that causes gastric pain in the mouth and esophagus attacking the mucous membrane, which was intended to cure not to worsen the pain. It contains not less than 99.5 percent of 2-(acetyloxy)benzoic acid. Aspirin is a...
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...silicon 14 | aluminium ← silicon → phosphorus | C ↑ Si ↓ Ge | Periodic Table - Extended Periodic Table | | | General | Name, Symbol, Number | silicon, Si, 14 | Chemical series | metalloids | Group, Period, Block | 14, 3, p | Appearance | dark gray, bluish tinge | Atomic mass | 28.0855(3) g/mol | Electron configuration | [Ne] 3s2 3p2 | Electrons per shell | 2, 8, 4 | Physical properties | Phase | solid | Density (near r.t.) | 2.33 g·cm−3 | Liquid density at m.p. | 2.57 g·cm−3 | Melting point | 1687 K (1414 °C, 2577 °F) | Boiling point | 3538 K (3265 °C, 5909 °F) | Heat of fusion | 50.21 kJ·mol−1 | Heat of vaporization | 359 kJ·mol−1 | Heat capacity | (25 °C) 19.789 J·mol−1·K−1 | P/Pa | 1 | 10 | 100 | 1 k | 10 k | 100 k | at T/K | 1908 | 2102 | 2339 | 2636 | 3021 | 3537 | Vapor pressure | | Atomic properties | Crystal structure | Diamond Lattice | Oxidation states | 4 (amphoteric oxide) | Electronegativity | 1.90 (Pauling scale) | Ionization energies (more) | 1st: 786.5 kJ·mol−1 | | 2nd: 1577.1 kJ·mol−1 | | 3rd: 3231.6 kJ·mol−1 | Atomic radius | 110 pm | Atomic radius (calc.) | 111 pm | Covalent radius | 111 pm | Van der Waals radius | 210 pm | Miscellaneous | Magnetic ordering | nonmagnetic | Thermal conductivity | (300 K) 149 W·m−1·K−1 | Thermal expansion | (25 °C) 2.6 µm·m−1·K−1 | Speed of sound (thin rod) | (20 °C) 8433 m/s | Young's modulus | 47 GPa | Bulk modulus | 100 GPa...
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