Determination Of Vitamin C Content Of Tablet Essay

ABSTRACTIn this prove, the vitamin C satisfy of a commercial pad is determined and comp bed with the shapers ad hocation. Vitamin C is pee-soluble and is an enantiomorph of ascorbic acerbic. (Commercial vitamin C is often a potpourri of ascorbic point and other ascorbates.) Ascorbic vinegarish, C6H8O6, is a reducing mover that reacts rapidly with iodine (I2). As the iodine is added during the titration, the ascorbic pane is oxidized to dehydroascorbic acid, season the iodine is minify to iodide ions as shown in the following equation.Ascorbic acid + I2 (aq) 2I- (aq) + dehydroascorbic acidimputable to this response, the iodine formed is at one time reduced to iodide as long as at that place is any ascorbic acid cede. The amount of ascorbic acid is determined by the stoichiometry of the equations and the variance mingled with the total amount of iodine present and the amount that reacts with the thiosulphate. This method is suitable for give with vitamin C pads, fresh or incase fruit juices and solid fruits and vegetables.INTRODUCTIONVitamins be a group of small seawallecular compounds that argon of the essence(p) nutrients in galore(post no.inal) multi-cellular organisms, and charitables in particular. L-Ascorbic acid was number cardinal isolated as a double-dyed(a) substance by Albert Azent-Gyorgi and Charles Kingin 1928 (Pauling, 1970), an anti-oxidant and free report scavenger, is found ubiquitously in fruit and vegetables such(prenominal)(prenominal) as citrus fruits (oranges, lemons, limes, tangerines etc.), melons, tomatoes, peppers, broccoli, green two-leaved vegetables such as spinach, potatoes and turnips, its quantitative close is especially fundamental in the take 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 gracious diet and necessary to growth and bear on of tissues in all parts of human body .It is neces sary to form collagen an important skin proteins ,scar tissue ,t leftoverons, ligaments, and blood vessels. Vitamin Cis essential for the healing of wounds, and for the repair and sustentation of cartilage, bones and teeth (Mcevoy, 1993) one of the some(prenominal) ways of determining the ascorbic acid subject field of a answer is by titration. count on structure of vitamin c (ascorbic acid)Titration is a strengthtric analysis and is one of the basic analytical techniques in chemistry which enables one to quantitatively determine how much of a specific substance is contained in a presumption sample. This technique is concernd in or so every aspects of our daily living such as life sciences, clinical chemistry, water pollution, industrial analyses etc. In localize to make meaningful titration analysis, one has to record and learn the principles involved. Several types of titration techniques are flat available but, two general types which are still in much expenditure are acid-base and reduction-oxidation (Redox). Acid-base titration involves the neutralization reaction and the products are generally salt and water. Redox titrations involve the titration of an oxidizing agent (or oxidant) with a reducing agent (or reductant) or vice versa. Oxidation impact involves loss of electrons while reduction fulfil 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 endure completion with a sharp end point.MATERIALS AND METHOD250-mL conelike flaskfulVitamin C inking pads400-mL beakerKBrO2 popcome50-mL, 25ml and 10ml measuring cylinder10% KI solving50-mL buret with tie2.0 M H2SO4 solutionGlass intake rodStarch indicator analytic balanceA. STANDARDIZATION OF SODIUM THIOSULPHATE1. A warning titration setup was framed up using a stand, a burette clamp and a white coverFigure 2 setup for titration(Courtesy of http//www.chemteach.ac.nz)2. A burette was rinsed with distilled water and hence with the give sodium thiosulphate solution. 3. With the stopcock closed, the rinsed burette was in full filled up with the sodium thiosulphate solution and then the stopcock was opened so that the tip of the burette was also allowed to be filled up. The initial burette rule book was recorded to an accuracy of 2 quantitative 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 conelike flask using the rinsed pipette. 6. utilize 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 solution until a warp yellow 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 disgraceful blue to affectationless. The final burette reading, close to 2 decimal places, was recorded. the volume of the sodium thiosulphate solution added was calculated 11. Apart from the initial trial, 2 more(prenominal) successive titrations were carried out. The burette was refilled in between runs when the volume stay was not enough for a everlasting(a) titration.B. ANALYSIS OF VITAMIN C TABLETSFigure 3 vitamin c lodgingss(Courtesy of lule.blogspot.com)1. A tablet of vitamin c was transferred into a 250ml conical flask and near 40cm3 of 2M H2SO4 was added. The tablet was then crushed to sever until a solution formed.2. Using a measuring cylinder, 10cm3 of 10% KI solution was added to the tablet solut ion and 25cm3 of standard KIO3 solution was pipetted in to the flask.3. The solution was then immediately titrated with standard thiosulphate solution in the burette until the dark color changed to the pilot burner color of the tablet.4. This procedure was repeated with 2 more samples of the tablet.5. The volume of sodium thiosulphate apply in each titration was recorded and the average volume was calculated.RESULTS AND CALCULATIONSTRIALSINITIAL READINGSFINAL READINGS titer garishnessAVERAGE TITER10.8533.6032.7532.3320.8033.1032.30314.8546.8031.95Table solvings from standardization of sodium thiosulphate (A) Number of moles of KBrO3 in 25cm3 solution = this rule is used because the molarity of the solution is habituated and the volume is known0.009640.025=0.000241molMass of KBrO3 solution used= this formula is used in ancestry the mass 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= 0.01446molMoles of I2 liberate = 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 CenovisManufacturers specification of vitamin c tablet 1000mg of vitamin c per tablet submarine sandwich 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 moles no.of moles of Na2S2O3 require to react with excess I2Moles of I2 that reacted with sodium thiosulphate zero(prenominal) of mole of Na2S2O3 =No. of mole of original 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 = 0.0055Mass of ascorbic acid = 1760.0055= 0.92g =920mgCONC LUSIONThe experiment was successfully carried out and the results were encouraging. 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. However the resultsfrom the experiment showed divergent 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 infra the manufacturers specification. However this actus reus could be as a result of different factors 1. The manufact urer of the tablet make wrong(p) analysis of the tablet. 2. This experiment contained 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 department of Agriculture. Mcevoy, G. (1993). medicate information the american hospital formulary service. American society of health-system pharmacist. Pauling, l. (1970). vitamin c and the uncouth cold.studymode.js. (2010). commercial vitamin c tablet analysis. Retrieved from studymode http//www.studymode.com/essays/Commercial-Vitamin-c-Tablets-Analysis-470526.html