Analysis of Commercial Vitamin C Tablets. (Ascorbic acid content in one tablet)

Date: 25 Nov, 2004 Objective: 1. To warningize sodium thiosulphate for titration use. 2. To vex surface the soaking up of Vitamin C in the tablet. Theory: This try out involves titration of oxidoreduction play offion. Redox reaction means reduction and oxidation. In which oxidizing actor and minify means are mixed and oxidate/reduce each other. virtuoso losses electron(s) and increase in oxidation number when is oxidized, and immorality versa. In order to find out parsimony of the ascorbic irate in the tablet, a redox reaction of it with tincture of single was done. While single is an oxidizing agent and ascorbic virulent is a reducing agent. The reaction forms dehydroascorbic acid and iodide. Ascorbic acid + I2 -> dehydroascorbic acid + 2 H+ + 2 I- However, iodine does non dissolve in water very well. In this case, mensuration solution of thou iodate(V) is used to produce sedimentary iodine. redundant potassium iodide and dilute sulphuric acid is ad ded to react with potassium iodate. KIO3 + 5 KI + 3 H2SO4 -> 3 I2 + 3 pee + 3 K2SO4 Excess potassium iodide also helps dissolving iodine produced. I-(aq) + I2(s) I3-(aq) Iodine does not react with ascorbic acid too quickly, that is wherefore they fagnot be titrated directly. We use excess iodine solution to react with restrict vitamin C. Iodine left is then titrated with sodium thiosulphate, a reducing agent, thus number of mole of iodine reacted with vitamin C can be found out.

This technique is known as gage titration. Sodium thiosulphate absorbs water in the atmosphere with time. Its concentration decreases with time as volume of water increases. In ! this case, standization of sodium thiosulphate is needed. Sodium thiosulphate is titrated with standard iodine solution, and the concentration of it can be found out. 2 Na2S2O3 + I2 -> Na2S4O6 + 2 NaI... if you see a -& vitamin A;amp;gt it is an right arrow, unspoiled to remind you that.. ill try to grow it.. -_- If you want to get a full essay, order it on our website: OrderCustomPaper.com

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