Determination of Chlorine and Iodine in Water Essay

I. IntroductionThe purpose of this lab was to determine the amount of centiliter and atomic number 53 in a sample of body of piss by titration using a amylum indicator and to regularise a atomic number 11 thiosulfate stem. centiliter is added to municipal peeing supplies to consecrate it enough to become strong to drink. unity is also added to pee when people large number or go hiking in the blanket country where they rumpnot bring purified water along. centiliter and unity are added to efface microorganisms in water. Oxidation reactions occurred in this experiment. The centilitre was oxidize because it lost electrons in the reaction. The atomic number 53 was trim down because it gained electrons. The upshots lifted a scandalmongering contort because of the atomic number 53 which disappears once either of the iodine has reacted in the titration. atomic number 11 thiosulfate was the titrant in the attend of titration. It was added to react with the i odine in the dissolving agent. stiffen was added to give the effect a downhearted air near the terminal of the titration. cat valium iodate (KIO) was utilise to measuringize the sodium thiosulfate settlement. concrete applications would include testing unknown samples of water and municipal water supplies for the assimilation of atomic number 17 present because also much can cause health problems and not degustation well. Not enough added, wouldnt kill the microorganisms in the water to make it safe to drink.II. ProcedureFirst the standardization of Sodium Thiosulfate was completed. A 50mL burettete was obtained and rinsed twice with the sodium thiosulfate solving. It was then filled with the consequence. The tip of the buret was checked to make sure in that respect werent any bubbles in it. thence a 250mL beaker was obtained. A 25mL pipette was employ to add exactly 25mL of the KIO result. therefore 50mL of deionized water and about .25g of satisfying KI was ad ded. The solution was stirred until the solid was completely dissolved. 2mL of nippy acetic pane was then added. then(prenominal), the beaker was placed under the buret and was swirled as the sodium thiosulfate was added. The buret was slowed as the air became lighter. When the polish was almost gone, 1mL of the starch solution was added to turn the solution deplorable. and so it was slowly titrated until the chroma disappeared. The concluding volume of the solution in the buret was enter and the amount of titrant was calculated. This titration was restate twain to a greater extent times to standardize the slow-wittedness of the thiosulfate. Then the submersion of Chlorine in beg water was found. It was tell the almost exactly the same direction as before.The buret was filled with the sodium thiosulfate solution and the initial value was recorded. Then a 50mL watch cylinder was rinsed with knap water two to three times. The gradational cylinder was then filled w ith refrigerant tap water. It was then poured into a loose beaker and .25g of KI and 2mL glacial acetic mordant were added and stirred until the solid was dissolved. Then the solution was titrated. 1mL of starch was added then the yellow people of color almost disappeared. It was then titrated slowly until the blue color disappeared. The final volume was recorded and the volume of titrant used was determined. This was repeated two to a greater extent times.Then the concentration of iodine was determined in the iodine purified water. The buret was refilled and the initial volume was recorded. Then the 50mL graduated cylinder was rinsed with the iodine solution. 50mL of the iodine solution was then obtained and poured into a clean beaker. Then .25g of KI and 2mL of acetic acid were added and the solution was stirred until it was dissolved. Then it was titrated until the yellow color almost disappeared. 1mL of starch was then added and the solution was titrated slowly until the blu e color disappeared. The final volume was recorded and the volume of titrant used was then determined. This was repeated two more(prenominal) times. Then everything was cleaned and put away.III. Data and Results control board 1 calibration of Sodium Thiosulfate result initial burette account book (mL) last Buret passel (mL) Volume apply (mL) beginning(a) Standardization 50 25.64 24.36second Standardization 50 25.99 24.01third Standardization 50 26.21 23.79 dodge 2 Titration of Tap peeing Initial Buret Volume (mL) Final Buret Volume (mL) Volume Used (mL) 1st Titration 50 48.29 1.17second Titration 50 48.25 1.753rd Titration 50 48.20 1.80Table 3 Titration of Iodine root Initial Buret Volume (mL) Final Buret Volume (mL) Volume Used (mL) 1st Titration 50 45.61 4.392nd Titration 50 45.59 4.413rd Titration 50 45.60 4.40Table 4 honest Concentrations Molarity ( breakwateres/ cubic decimeter)Sodium Thiosulfate Solution 1.0610Chlorine in Tap Water 1.8610Iodine in Solution 4.6610Samp le Calculation- Concentration of Chlorine(1.0610)*(0.00175L)=1.8610 breakwateres thiosulfate(1.8610mol thiosulfate)*(1 mol Cl/2 mol thiosulfate)=9.2810 mol Cl (9.2810mol Cl)/.05L=1.8610 moles Cl/LiterIn the first standardization of the sodium thiosulfate solution, 24.36mL of the titrant was used. 24.01mL and 23.79mL were used for the second and third standardizations. With the concentration of the sodium thiosulfate solution divided the average volume of those gave the average thiosulfate concentration which was 1.0610 moles per liter. For the titration of tap water, an average of 1.75mL of the sodium thiosulfate solution was used. after the calculations, the concentration of atomic number 17 in tap water was 1.8610 moles of atomic number 17 per liter.The average of the titrations of the iodine solution was 4.40mL of titrant used. After the calculations, 4.6610 moles of iodine were present per liter. many useful observations were conducted. The iodine in the solution made it turn a yellow color when the glacial acetic acid was added. It started to disappear as the iodine was reacting with the titrant. When the starch solution was added, the solution turned blue. As the resultant neared, the blue color started to dissipate. When the endpoint was reached, the solution was clear with no color left in the solution. Sources of error could include adding too much titrant from the buret into the solution.IV. final resultThe purpose of this lab was to identify the concentration of chlorine and iodine in unlike samples of water. The results fulfilled the purpose of this lab because the concentrations of chlorine and iodine were found. The concentration of chlorine in the tap water was 1.8610 moles of chlorine per liter. The molarity of iodine in the iodine water solution was 4.66 x10 moles per liter. The concentration of iodine was significantly higher than the amount of chlorine in tap water. There was more iodine in the water because of the solid KI being added to the solution. Tap water contains sm both amounts of chlorine because thats all that is needed to kill the microorganisms living in the water that are harmful to people. The results that were obtained were unanticipated because there wasnt a standard value to go off of. The portion error wasnt able to be obtained.Possible sources of error would include adding too much of the titrant to the solution. This would affect the results by having more than enough titrant used. This would affect the concentration value and make them higher than they really were. chemical substance concepts used were titrations. When the Iodide ions, from the potassium iodide, react with the chlorine in the tap water, chloride ions and I were formed. Then the I was titrated with the sodium thiosulfate solution which created the iodide ions. in the beginning the endpoint of the titration, the starch was added.Once all of the iodine reacted with the thiosulfate, the blue color disappeared because the endpoi nt was reached and the iodide ions were formed. Also the standardization of the sodium thiosulfate solution was performed. When the potassium iodate reacted with the solid KI and the acetic acid, it created I and water. The I was titrated and formed with the thiosulfate and created iodide ions also. The concentration of the thiosulfate was 1.0610 moles per liter. That result was expected because it should have been around .001 M and it was .00106 M.