Afterwards an extraction is used to separate the organic layer (bottom) from the aqueous layer (upper). By using a rotary evaporator‚ it evaporates the organic solvent and forms the crude caffeine. Afterwards we used acetone-petroleum ether for recrystallization and the vacuum apparatus for filtration to obtain pure caffeine. At the end the melting point of the pure caffeine was obtained. (Reference: Organic Chemistry Laboratory Manual) Experiment Scheme: We used 250 mL of water and 20.08 g
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Guide Questions Experiment 1 Calibration of the calorimeter: 1. Give the net ionic thermochemical equation of the reaction used to calibrate the calorimeter. a. Is the reaction endothermic or exothermic? b. Which is the limiting reactant? c. How much (in moles) limiting reactant was used? d. How much heat was generated (or absorbed) by the reaction? 2. Relate the sign of the ΔT to the ΔH of the reaction used for calibration. 3. What is the heat capacity of the calorimeter? Relate
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The purpose of this experiment was to perform a wittig reaction‚ the horner-emmons wittig specifically‚ reacting an aldehyde with an ylide to make an alkene. This particular variation of the wittig reaction has several advantages: It gives only the trans product; it uses a much milder base that is easier to handle; and it gives a water soluble byproduct which is easy to separate from the product. The reason that these advantages occur is a change in the structure of the ylide. Instead of a tripheylphosphine
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ASSIGNMENT ON PHARMACEUTICAL IMPORTANCE OF STEREOCHEMISTRY PREPARED FOR: Nowshin Nowaz Rumzhum Lecturer‚ Dept. of pharmacy Stamford University Bangladesh PREPARED BY: Md. Wahid Rezwan ID No: BPH02805674 Batch No: 28th D STAMFORD UNIVERSITY BANGLADESH Introduction: Stereochemistry may seem like a trivial
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to meta position. Nitric acid‚ sulfuric acid‚ and methyl benzoate will be mixed and added to an ice bath. Crushed ice will be added to this cold mixture and form crystals. After crystal product of m-methylbenzoate forms and purifies through recrystallization‚ its MP and IR will be taken to test purity and validate predicted position of the nitro group. Weight of final product will be compared to crude weight to determine effectiveness of procedure. It is possible to obtain small amounts of ortho
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The simplest way to synthesize an ether is to have an alkoxide react with a primary haloalkane or a sulfonate ester under typical SN2 conditions. The scientist who developed this reaction‚ Alexander W. Williamson‚ was a professor at University College in London in the latter part of the 1800’s. This reaction has been around a while! Secondary haloalkanes and sulfonate esters are occasionally used in the Williamson ether synthesis but the yields are often poor. The ether prepared in this experiment
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EXPERIMENT 4: Synthesis of Salicylic Acid from Wintergreen Oil Abstract: The purpose of this experiment is to take methyl salicylate (wintergreen oil) and by heating it under reflux with NaOH as a solvent‚ and then cooling the mixture with H2SO4 as another solvent‚ synthesize salicylic acid. The final step involves purify the product to produce as pure a sample of salicylic acid as possible. This process allowed for the successful production of 1.406g salicylic acid‚ an 82.70% yield. The NMR and
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At a granular level‚ rocks are composed of grains of minerals‚ which‚ in turn‚ are homogeneous solids formed from a chemical compound that is arranged in an orderly manner. The aggregate minerals forming the rock are held together by chemical bonds. The types and abundance of minerals in a rock are determined by the manner in which the rock was formed. Many rocks contain silica (SiO2); a compound of silicon and oxygen that forms 74.3% of the Earth’s crust. This material forms crystals with other
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Metals and alloys. Hume-Rothery rules. 1. Three types of metals. 2. Alloys. Hume-Rothery rules. 3. Electrical resistance of metallic alloys. 4. Applications of metallic alloys. 5. Steels. Super alloys. 6. Electromigration in thin wires. Three types of metals Metals share common features that define them as a separate class of materials: • Good thermal and electrical conductors (Why?). • Electrical resistance increases with temperature (Why?). • Specific heat grows linearly with temperature
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Experimental Synthesis of Aspirin and Melting Point Purity Analysis Donald Yeargin CH 222‚ Section 24221 Department of Chemistry Portland Community College Portland‚ OR Abstract The various methods available to synthesize aspirin lead to the need to examine and evaluate production efficiency and purity. The purpose of our experiment was to synthesize acetyl salicylic acid (aspirin) and then determine the relative purity of the synthesized sample by observing the melting point temperature
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