EXPERIMENT 2: Recrystallization and Melting Point Recrystallization (or Crystallization) is a technique used to purify solids. This procedure relies on the fact that solubility increases as temperature increases (you can dissolve more sugar in hot water than in cold water). As a hot‚ saturated solution cools‚ it becomes supersaturated and the solute precipitates (crystallizes) out. In a recrystallization procedure‚ an impure (crude) solid is dissolved in a hot solvent. As this solution is cooled
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Acid Rain Acid rain occurs when Sulphur Dioxide (SO2) is released into the atmosphere by electricity generation‚ motor vehicles‚ factories and by wildfires and volcanoes. Once released‚ the sulphur dioxide reacts with water to produce sulphuric acid. This has a pH of approximately 2-3 pH. This has a dramatic effect on water dwelling wildlife. Most water dwelling creatures can’t withstand water more acidic than pH 5. This causes the mass loss of life of animals such as trout‚ perch‚ frogs and mayflies
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CHAPTER 1 Introduction Background of the Study Like many other hygiene convenience‚ shoe polish or can also be called boot polish is usually a wax ‚ cream or paste used by people to shine‚ water proof and restore the appearance of leather shoes. This extends the footwear’s life. This is made up of many kinds of chemicals and because of this; it can cause irritations‚ allergies to us. In our generation‚ shoe polish is used every day and companies produce a lot of it to meet the demands of
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one of two very similar pentose rings. Ribonucleic acids contain the sugar ribose. Deoxyribonucleic acids contain the sugar deoxyribose. The only difference between these two sugars is that deoxyribose contains one oxygen atom less than ribose. Pentose sugars are essential because they are involved in linking different nucleotides together by condensation reactions. The Nitrogen-Containing Bases There are two types of bases found in nucleic acids. The purine bases have two nitrogen containing rings
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Methyl Red and Voges-Proskauer Test The Methyl Red test shows which bacteria are creating stable acids through mixed acid fermentation of glucose. This helps to identify enteric bacteria by examining how they metabolise glucose. Every enteric bacteria first produces pyruvic acid from metabolism of glucose. A methyl red positive enteric bacteria‚ uses the mixed acid pathway when breaking down pyruvic acid to different acids‚ like lactic‚ acetic‚ and formic acids. The Voges-Proskauer test determines
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ICSE Class X Chapter 5 Hydrogen Chloride and Hydrochloric Acid Hydrogen chloride (HCl) : Formula : HCl Nature : Covalent. Molecular Mass : 36·5u [i.e. HCl = 1 + 35·5 = 36·5] Occurrence : (i) Present in gastric juices. (ii) Present in volcanic gases. Laboratory preparation of HCl gas : Hydrogen chloride gas is prepared in laboratory by heating conc. H2SO4 with NaCl. NaCl + H2SO4 Heat → NaCl + NaHSO4 Heat → NaHSO4 + HCl Sodium hydrogen sulphate Na2SO4 + HCl
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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
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that mimics a natural flavor as that of banana flavor from the synthesis of isoamyl acetate. Ester is the functional group‚ which is responsible for the distinctive odor and taste that artificial fruit flavoring has. Esters are derived from carboxylic acids. A carboxylic acid contains the –COOH group‚ and in an ester the hydrogen in this group is replaced by a hydrocarbon group of some kind. This could be an alkyl group like methyl or ethyl‚ or one containing a benzene ring like phenyl[1]. Esters
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Essential Fatty Acids (EFAs) are fats that are required by the human body‚ but cannot be made by the body; therefore they must be obtained from external forces such as food. EFAs are the building blocks of all fats and oils and are required for both metabolic processes and for fuel. EFAs form the main component in the fats carried in our blood stream (triglycerides)‚ fats stored in our bodies and of cell membranes (phospholipids). (Erasmus‚ 1993)‚ (Wikipedia‚ Essential Fatty Acids‚ 2012) Two fundamental
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2.2 Application of Cu2O nanopowder 2.2.1 Photocatalyst 2.2.2 Solar energy conversion 2.3 Powder formation 2.4 Gas phase 2.4.1 Inert Gas Condensation (IGC) or Gas Phase Condensation 2.4.2 Chemical Vapor Deposition 2.4.3 Laser ablation 2.4.4 Flame synthesis 2.5 Liquid phase 2.5.1 Solvent evaporation method 6 6 7 7 8 9 9 11 11 11 12 12 13 Page ii iii vii viii xii xiii 1 2 3 4 5 pdfMachine iii Is a pdf writer that produces quality PDF files with ease! Produce quality PDF files in seconds and preserve
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