The crystallization of lysozyme to model a step for protein structure determination Asaad Ahmed November 6‚ 2014 TA: Ujwal Abstract: Discovery of new protein structures is essential for advancement in a variety of scientific fields. By determining structures of proteins‚ scientists are able to identify active sites‚ which can lead to accomplishments such as the development of pharmaceuticals that can enhance or inhibit certain proteins in a variety of signaling pathways. To determine protein structures
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the esterification of p-aminobenzoic acid with ethanol. The percent yield of crude product was determined to be 21% and the melting point was recorded at 86.2°C ± 0.2°C‚ with a 6.3% error from 92°C‚ the literature melting point of pure benzocaine. The crude product was then recrystallized to improve the purity of benzocaine and 57.4% was recovered. The new melting point range was measured at 89.1°C ± 0.3°C‚ which has a 3.15% error. The infrared spectrum of the recrystallized product was measured
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#1: THE PURITY AND PURIFICATION OF SOLIDS MELTING POINTS ABSTRACT Melting points of different mixtures of naphthalene and biphenyl were examined in this lab. Samples of these various mixtures were collected and tested by different individuals in the lab in order to find the eutectic point of biphenyl. Unknown substances were then tested using the mixture melting point method in order to determine their identities. INTRODUCTION The melting point of a solid is the temperature where the
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VI: Conclusion: The melting point of a compound is the temperature at which the solid is in equilibrium with its liquid. A solid compound changes to a liquid when the molecules acquire enough energy to overcome intermolecular forces holding them together in an crystalline lattice structure. The melting point range is defined as the span of temperature from the point at which the crystals first begin to liquefy to the point at which the entire sample is liquid. This data can be tabulated experimentally
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and Purification of Solids Melting Points CH-337 Abstract: The purpose of this experiment was to find the eutectic point for the mixture of naphthalene and biphenyl. This was done by measuring the melting point of both pure substances and five mixtures of different ratios. The purpose of the second section was to identify an unknown sample by measuring its melting point and mixing it with two known substances and comparing them. The results suggest that the eutectic point is closest to the weight
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Measuring the Melting Points of Compounds and Mixtures Introduction This exercise dealt with the melting points of pure mandelic acid and benzoic acid. The eutectic temperature and composition of mandelic and benzoic acid mixtures were determined. And finally‚ an unknown was identified by its mixtures and melting point. The melting point of a compound is used by organic chemists not only to identify the compound‚ but also to establish its purity. To determine the melting point two temperatures
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crystal Crystallization is a highly effective method for the purification of organic substances‚ provided that the physical properties of a given compound permits its purification in this manner. Solid organic compounds when isolated from organic mixtures or reactions are seldom pure; they are usually contaminated with small amounts of other compounds called impurities. Solid purification by crystallization is based upon different solubility in a given solvent. Simplest crystallization process
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Organic Chemistry Lab EXPERIMENT #2 and #3 Extraction and Evaporation Recrystallization and Melting Point Measurement PURPOSE: 1. To the components of a simulated pharmaceutical preparation‚ Panacetin‚ and identifying the unknown component of the mixture through extraction and separation methods. 2. To learn how to purify by recrystallization‚ how to dry them and how to obtain a melting point. PRECAUTION: ACETANILIDE AND PHENACETIN ARE EYE AND SKIN IRRITANTS. Minimize contact with
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Crystallization of Benzoic Acid Purpose: The purpose of this experiment is to purify benzoic acid by crystallization. Procedure: 1. 0.5g impure benzoic acid was placed in a 50mL Erlenmeyer flask. 15mL of water was added and the mixture was heated to a boil on a hot plate. 0.5mL of water was added to the flask‚ while swirling the flask. The mixture was boiled until the benzoic acid completely dissolved. The total volume of water used was recorded. The black solid that remain in the dissolved
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1: MELTING POINT AND BOILING POINTS OF ORGANIC COMPOUNDS ABSTRACT The properties of organic compounds depend on their chemical structures. Intermolecular forces of attraction affect physical properties such as melting and boiling point. Through the Thomas Hoover apparatus‚ the melting point of 8 test compounds was determined. Salicylic acid exhibited the highest melting point while naphthalene‚ the lowest. The stronger the intermolecular forces of attraction‚ the higher the melting point. Boiling
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