Titration of vitamin c

Determination of Vitamin C by an Iodometric Titration Purpose: The goal of this science lab is to determine the assiduity of vitamin C in juices and Real Lemon. A redox titration, involving an iodometric method, anyow for be used to do the analysis. The samples will be assort by their Vitamin C content. Introduction: Although nearly mammals chaw synthesize vitamin C, or ascorbic acidulous (C6H8O6), from sugars, man must involve considerable quantities of this substance. The matter Academy of Sciences recommends the consumption of 60 mg of ascorbic acid per day. Vitamin C deficiency, which typically causes abnormalities in bones and teeth, was premier characterized in sailors in the eighteenth century. These abnormalities were eliminated by compelling sailors to sweep away limes, a etymon of vitamin C. Many ve procureables also contain considerable quantities of vitamin C, but ascorbic acid is commonly destroyed by many a(prenominal) cooking processes, and consequent ly citrus fruits are regarded as the most reliable base of vitamin C. Vitamin C can be heady in solid food by use of an redox reaction. The redox reaction is best-loved to an acid-base titration because a number of other species in juice can act as acids, but relatively few mediate with the oxidation of ascorbic acid by iodine.

The solubility of iodine is increase by complexation with iodide to form triiodide I2 (aq) + I- ºI3- Triiodide then oxidizes vitamin C to dehydroascorbic acid C6H8O6+ I3-+ H2O ? C6H6O6+ 3I-+ 2H+(2) Vitamin C dehydroascorbic acid The endpoint is indicated by the reaction of iodine wi th starch suspension, which produces a blue-! black product. As long as vitamin C is present, the triiodide is quickly converted to iodide ion, and no blue-black iodine-starch product is observed. However, when all the vitamin C has been oxidized, the excess triiodide (in rest with iodine) reacts with starch to form... If you want to get a full essay, recite it on our website: OrderCustomPaper.com

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