the complication that macromolecules often have variations in chain length or molar mass even within a given sample. The idealized formula of polyvinyl alcohol is -(C2H2—CHOH)-n‚ which assumes consistent orientation in the addition of the vinyl acetate monomers1.
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Fischer Esterification is when an carboxylic acid and an alcohol reacts to produce an ester‚ catalyzed by a strong acid to protonate the -OH of the carboxylic acid‚ so it leave as water (Ketcha‚ 58). For Fischer Esterification to occur‚ the reaction must be heated up‚ without boiling away‚ for a prolong amount of time by refluxing the mixture (Ketcha‚ 57). Refluxing is the process in which the boiled solution’s vapors are condense back to a liquid and return to the boiled solution (Ketcha‚ 60). The
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low yields of the desired product. Gas chromatographic analysis of mono and disaccharides requires conversion of sugars into their volatile derivatives. Conversion of sugars into alditol acetates and trimethylsilyl (TMS) ethers have been the most widely used methods for GC analysis of sugars. "Alditol acetate" method involves reduction of sugars with sodium borohydride following conversion of polyols to polyacetate esters. TMS ethers of sugars can be prepared from a number of commercially available
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The purpose of this experiment is to synthesize isopentyl ester by an esterification reaction between a carboxylic acid and an ester. Carboxylic esters‚ like isopentyl acetate‚ are normally used to create artificial flavors. In the preparation of isopentyl acetate‚ esterification of acetic acid and isopentyl alcohol occurs. Esterification is an equilibrium shift to the product side using an excess of one of the starting components. In this experiment‚ the excess reagent is acetic acid because it
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Utilization of glucose by the muscle and liver cell cultures was enhanced by the water and n-hexane/isopropanol extract of the plant but not on adipose cells (Erasto et al.‚ 2009). In another study‚ oral intake of hot water V. amygdalina leaves extract (500 mg/kg) reduced blood glucose concentration of both normoglycaemic and hyperglycaemic rats induced by alloxan (Osinubi‚ 2007). 2.4.2.3 Antioxidant activity Several studies have shown that V. amygdalina possess antioxidant activity (Yeap et al
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catalyst. The percent yield of the product was sub-par. It was found to be 54.4%‚ which may have been due to the formation of other byproducts during the experiment. For example‚ the benzoin and copper(II) acetate mixed with ammonium nitrate and acetic acid could have caused the copper(II) acetate to not fully react with the benzoin. This side-reaction led to less benzoin intermediate which in turn led to a less yield of benzil product. Additionally‚ the melting points found were similar to that of
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was purchased from Fluka‚ Switzerland. All the other chemicals and solvents used were of AR grade. UV SL-159 Elico make spectrophotometer was used for the studies. A standard solution of GLS (1000 µg/ml) was prepared in 0.1 M aqueous sodium acetate solution. (S1). Ten tablets (Cartilamine®
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1. uncharged object such as paper? A charged object will attract an uncharged object until they touch‚ and then they will repel one another. When charged objects attract uncharged objects‚ such as when the negatively charged plastic comb or fur attracted the paper‚ the negatively charged comb/fur repelled some of the electrons in the paper. This results in a redistribution of charges in the paper so that one side is more negative than the other side. The net effect is that the paper is attracted
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a methoxy group (-OCH3). Similarly‚ ethyl acetate (CH3CO-OCH2CH3) is made up of acetic acid (CH3CO-OH) in which the hydroxy group has been replaced by an ethoxy group (-OCH2CH3) Although esters can be produced by many mechanisms‚ the most commonly used method is called esterification‚ which is a condensation reaction between an alcohol and an acid‚ typically in the presence of a strong acid catalyst‚ such as sulfuric acid. For example‚ ethyl acetate can be produced by reacting ethanol (ethyl
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Chem formula Type Experimental pH 1 Deidre Acetic Acid 0.1M HC2H3O2 Weak Acid 3.03 3.03 2 Acetic Acid 1M HC2H3O2 Weak Acid 2.59 2.54 3 Hydrochloric Acid 0.5M HClStrong Base 0.85 0.90 4 Jonah Nitric Acid 0.1M HNO3 Strong Acid 2.14 2.14 5 Sodium Acetate 1M NaC2H3O2 Weak Base 9.42 9.42 6 Potassium Dihydrogen Phosphate 0.1M KH2PO4 Weak Acid 5.47 5.47 7 Andy Potassium Hydrogen Phosphate 0.05M K2HPO4 Weak Base 7.71 7.73 8 Ammonium Chloride 0.2M NH4Cl Weak Acid 4.65 4.67 9 Sodium Hydroxide 0.1M NaOHStrong
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