Determination Of Vitamin C Content Of Tablet Essay

ABSTRACTIn this experimentation, the vitamin C content of a commercial pad is determined and comp bed with the manufacturers limitedation. Vitamin C is water-soluble and is an enantiomer of ascorbic irate. (Commercial vitamin C is often a mixture of ascorbic social disease and other ascorbates.) Ascorbic astringent, C6H8O6, is a decrease agent that opposes rapidly with iodine (I2). As the iodine is added during the titration, the ascorbic acid is oxidized to dehydroascorbic acid, while the iodine is reduced to iodide ions as shown in the following equation.Ascorbic acid + I2 (aq) 2I- (aq) + dehydroascorbic acidDue to this reaction, the iodine form is nowadays reduced to iodide as long as there is whatsoever ascorbic acid present. The essence of ascorbic acid is determined by the stoichiometry of the equations and the difference mingled with the total amount of iodine present and the amount that reacts with the thiosulphate. This method is able for use with vitamin C tab lets, fresh or packaged fruit juices and full-blooded fruits and vegetables.INTRODUCTIONVitamins are a group of sm every last(predicate) molecular compounds that are essential nutrients in many multi-cellular organisms, and humans in particular. L-Ascorbic acid was head start isolated as a pure substance by Albert Azent-Gyorgi and Charles Kingin 1928 (Pauling, 1970), an anti-oxidant and clean-handed radical scavenger, is found ubiquitously in fruit and vegetables such as citrus fruit fruits (oranges, lemons, limes, tangerines etc.), melons, tomatoes, peppers, broccoli, green leafy vegetables such as spinach, potatoes and turnips, its quantitative determination is specially important in the production of wine, beer, milk, soft drinks and fruit juices, where it can be a quality indicator (Gerrior & Zizza, 1994) .Given the essential role played in the human diet and necessary to growth and repair of tissues in all parts of human body .It is necessary to form collagen an important scratch proteins ,scar tissue ,tendons, ligaments, and blood vessels. Vitamin Cis essential for the healing of wounds, and for the repair and aliment of cartilage, bones and teeth (Mcevoy, 1993) one of the several ways of determining the ascorbic acid content of a consequence is by titration.Figure structure of vitamin c (ascorbic acid)Titration is a hoi polloitric analysis and is one of the basic analytical techniques in chemistry which enables one to quantitatively determine how such(prenominal) of a specific substance is contained in a given sample. This technique is involved in almost every aspects of our daily living such as lifespan sciences, clinical chemistry, water pollution, industrial analyses etc. In order to nominate meaningful titration analysis, one has to understand and learn the principles involved. Several types of titration techniques are at a time available but, two general types which are still in much use are acid-base and reduction-oxidation (Redox). A cid-base titration involves the neutralization reaction and the products are generally brininess and water. Redox titrations involve the titration of an oxidizing agent (or oxidant) with a reducing agent (or reductant) or vice versa. Oxidation fulfill involves loss of electrons while reduction process involves gain of electrons. Thus an oxidizing agent is one which accepts electrons while a reducing agent is one which loses the electrons. There must be a sufficiently large difference between the oxidizing and reducing capabilities of these agents for the reaction to undergo mop up with a sharp end point.MATERIALS AND METHOD250-mL conical flaskfulVitamin C tablets400-mL beakerKBrO2 declaration50-mL, 25ml and 10ml mensuration cylinder10% KI solution50-mL burette with stand2.0 M H2SO4 solutionGlass stirring rod stiffen indicatorAnalytical balanceA. STANDARDIZATION OF SODIUM THIOSULPHATE1. A normal titration setup was framed up using a stand, a burette clamp and a white tileFigur e 2 setup for titration(Courtesy of http//www.chemt individually.ac.nz)2. A burette was rinsed with distilled water and thus with the given sodium thiosulphate solution. 3. With the dick closed, the rinsed burette was fully filled up with the sodium thiosulphate solution and thus the stopcock was opened so that the tip of the burette was also allowed to be filled up. The initial burette volume was recorded to an accuracy of 2 decimal places 4. A 25.00cm3 pipette was rinsed with distilled water, and then with KBrO3 solution. 5. 25.00cm3 of standard solution of KBrO3 was transferred to a clean conical flask using the rinsed pipette. 6. Using a 25cm3 measuring cylinder, 25ml of 2M H2SO4 was transferred into the conical flask containing the KBrO3 solution. 7. Using a 10ml measuring cylinder, 5ml of 10% KI solution was also added to the conical flask containing the KBrO3 solution. 8. Immediately, the reaction mixture in the conical flask was titrated with the sodium thiosulphate soluti on until a pale xanthousish solution was observed. 9. A few drops of starch solution were added to the pale yellow solution in the conical flask. 10. Titration of the mixture was continued until the solution changed from stern blue to colorless. The final burette reading, accurate to 2 decimal places, was recorded. the volume of the sodium thiosulphate solution added was calculated 11. Apart from the first trial, 2 to a greater extent successive titrations were carried out. The burette was refilled in between runs when the volume remaining was not enough for a complete titration.B. ANALYSIS OF VITAMIN C TABLETSFigure 3 vitamin c tablets(Courtesy of lule.blogspot.com)1. A tablet of vitamin c was transferred into a 250ml conical flask andapproximately 40cm3 of 2M H2SO4 was added. The tablet was then suppress to dissolve until a solution formed.2. Using a measuring cylinder, 10cm3 of 10% KI solution was added to the tablet solution and 25cm3 of standard KIO3 solution was pipetted i n to the flask.3. The solution was then immediately titrated with standard thiosulphate solution in the burette until the dark color changed to the lord color of the tablet.4. This procedure was repeated with 2 more samples of the tablet.5. The volume of sodium thiosulphate used in each titration was recorded and the average volume was calculated.RESULTS AND CALCULATIONSTRIALSinitial READINGSfinal exam READINGSTITRE VOLUMEAVERAGE TITER10.8533.6032.7532.3320.8033.1032.30314.8546.8031.95Table results from standardization of sodium thiosulphate (A) Number of moles of KBrO3 in 25cm3 solution = this formula is used because the molarity of the solution is given and the volume is known0.009640.025=0.000241mol battalion of KBrO3 solution used= this formula is used in deriving the down of a substance when the no. of moles is given (or derived)=0.000241mol167g/mol=0.040247g= 40.25mgConcentration of KBrO3 = zero(prenominal) of moles of Na2S2O3 required for one titration = 0.00241mol6= 0.0144 6molMoles of I2 liberated = 2.4110-4 molesConcentration of Na2S2O3= 0.298mol/dm3TRIALSINITIAL READINGSFINAL READINGSTITRE VOLUMEAVERAGE TITER18.8011.702.903.43211.7015.203.50315.2019.103.90Table 2 results from vitamin C analysis (B)Brand of vitamin C Cenovismanufacturing businesss specification of vitamin c tablet 1000mg of vitamin c per tablet molar mass of vitamin C (C6H8O6) = 126+18+166=176g/molBalanced Equation for reaction = KIO3+5KI+3H2SO4 3I2+3H2O+3K2SO4Number of moles of KIO3 in 25cm3 solution = 0.00100 molMoles of I2 produced by 25cm3 of KIO3= 0.001003= 0.003 molesNo of moles of Na2S2O3 needed to react with excess I2Moles of I2 that reacted with sodium thiosulphateNo. of mole of Na2S2O3 =No. of mole of genuine I2 no. of mole of excess I2 =0.000723- 0.0005=0.000223molNo. of mole of I2 that reacted with ascorbic acid = 0.006-0.0005 = 0.0055 portion of ascorbic acid = 1760.0055= 0.92g =920mgCONCLUSIONThe experiment was successfully carried out and the results were encouragin g. The analysis of the vitamin c content of the Cenovis tablet was carried out using titration. The vitamin c tablet was crushed into a conical flask and specific amounts of KI and KIO3 were added. The solution was then titrated with standard thiosulphate solution until the required color was derived. The results were recorded and calculations to determine the amount of ascorbic acid in each tablet was also successfully done. heretofore the resultsfrom the experiment showed different values from the manufacturers specifications. The manufacturer (Cenovis) claims that each vitamin c tablet contains 1000mg of ascorbic acid while this experiment shows otherwise. After calculations were done, the experiment found each vitamin c tablet to be containing about 920mg of ascorbic acid which is below the manufacturers specification. However this error could be as a result of different factors 1. The manufacturer of the tablet made reproach analysis of the tablet. 2. This experiment containe d errors which arose from wrong reading of instruments, wrong calibration of instruments, or errors in uncertainty.Works CitedGerrior, S., & Zizza, C. (1994). Nutrient content of the U.S food supply, 1909-1990. Washington D.C U.S subdivision of Agriculture. Mcevoy, G. (1993). Drug information the american hospital formulary service. American orderliness of health-system pharmacist. Pauling, l. (1970). vitamin c and the common cold.studymode.js. (2010). commercial vitamin c tablet analysis. Retrieved from studymode http//www.studymode.com/essays/Commercial-Vitamin-c-Tablets-Analysis-470526.html