Ap Chemistry Redox Titration Lab

Redox Titration Lab ABSTRACT In this research research laboratory, 0. 010 M purple-colored jet permanganate issue was amountized by redox titration with beseech (II) ammonium convert hexahydrate (FAS). The average stool of the three flaskfuls of FAS was 0. 483 grams. Once the stringency of the standard base of KMnO4 (aq) was determined, it was use to determine the preoccupancy of Fe2+ in branding crusade tabs. On average, in that respect was 0. 01813 L of etymon used.With this information and the balanced net-ionic equation 10Fe(NH4)2(SO4)2*6H2O+2KMnO4+H2SO4 5Fe2(SO4)3+(NH4)2SO4+K2SO4+2MnSO4+H2O, the average division by plenty piece of music of Fe2+ in iron pill samples was 16. 99%. (103) INTRODUCTION The scientific concept of this lab was to titrate potassium permanganate with iron (II) ammonium sulfate hexahydrate in order to oxidize the Fe2+ to Fe3+. Then the tautness of the standard solution of KMnO4 (aq) will be used to determine the concentration of Fe2+ in iron pills. The purpose of the lab is to number one standardize a stock KMnO4 (aq), and then determine the per centum Fe2+ in iron pills. canvass this Practice Test Chem 105The expected outcome of this lab was for the percentage of Fe2+ in the iron pills to be 17%. This is what was on the bottle of iron pills, and the occlusive of the lab was to use titration to retrieve as much(prenominal) if the iron as possible. MATERIALS AND METHODS The procedure for the standardization of KMnO4 (aq) was to first fill a clean 50 mL buret with 0. 0100 M KMnO4 (aq). Three clean Erlenmeyer flasks unavoidable to be labeled, and a humankind of FAS needed to be weighed to 0. 5g on a piece of calculation paper. flaskful 1 was tarred and feeped into the FAS. The mass was then recorded. This was then recurrent with flask 2 and 3. 0 mL of water and 5 mL of 3M H2SO4 was added to the three flasks. 50 mL of water was put in a beaker and 1 drop of permanganate solution was added. The color intensi ty of the mixture matched the standard and remained for 5 seconds or more. The initial record book was recorded to 0. 01 mL. Permanganate was then added to the FAS solution in flask 1 until the equivalent point was r severallyed. The final volume was recorded and the permanganate solution used was determined. The titration dish out was retell using FAS in flask 2 and 3. The flasks were then washed down the drain and rinsed with distilled water.Moles of Fe2+ ions set out was wagerd from the mass of FAS. The balanced equation was used to relegate the seawalles of KMnO4 needed to reach the same point. The three groinarities of the permanganate solutions were then calculated. The molarities were added to the class selective information which would calculate the overall molarity for permanganate solutions. The procedure for the analysis of the iron pill was to first grind 2 iron pills in a mortar and pistol. at that place was 63 mg of iron per pill. 0. 3 grams was weighed on we ighing paper, and an Erlenmeyer flask was tarred. The powder was then put in the flask and massed to 0. 01 g. This was then repeated with the second sample. 25 mL water, 15 mL 3M H2SO4, and a few drops of H3PO4(aq) was added to each flask and swirled until the iron pill was dissolved. The initial volume of the discipline in the buret was recorded, and permanganate was added to the iron pill solution in flask 1 until the same point is reached. The final volume reading was recorded, and the take away volume of the permanganate used was found. The titration process was repeated using the iron pill in flask 2. The mixtures in flasks were washed down the drain, and the flasks were rinsed with water.The buret was rinsed with tap water and the stopcock was open for storage. RESULTS Standardization FAS mass Flask 1 0. 500 gtarred 0. 485 g FAS mass Flask 2 0. 501 gtarred 0. 496 g FAS mass Flask 3 0. 497 gtarred 0. 467 g KMnO4 Initial V (mL) Final V (mL) Solution used (mL) Titration 1 0. 0 1 25. 45 25. 44 Titration 2 0. 00 26. 36 26. 36 Titration 3 0. 00 24. 31 24. 31 Iron pads Iron Pill mass Flask 1 0. 286 g Iron Pill mass Flask 2 0. 293 g KMnO4 Initial V (mL) Final V (mL) Solution used (mL) Titration 1 0. 00 18. 09 18. 09 Titration 2 0. 00 18. 17 18. 7 The selective information found in this lab allowed for the disco genuinely of the percentage by composition of Fe2+ in the iron pills. For the standardization data, the different titrations is the in hooked variable, and the volumes of KMnO4 is the dependent variable. In order to find the percentage by composition of Fe2+ in the iron pills, the KMnO4 needed to be titrated and the starting, final, and solution used needed to be recorded. The solution used will later be used in liters to find the molarity of each flask of KMnO4. The data above the table is how much FAS was in each flask when it was tarred, and with the flask itself.For the iron pills data, the different titrations is the dependent variable, and the volumes of KMnO4 is the dependent variable. For each titration, the initial, final, and solution used is recorded on this data table also. The solution used will later be used in liters to determine the grams of Fe2+. The data above the table is how much iron was in each flask measured in grams. CALCULATIONS Flask 1 0. 485g (1 mol FAS/392. 16g) (2 mol KMnO4/10 mol FAS) = 2. 473*10-4 mol KMnO4 Flask 2 0. 496g (1 mol FAS/392. 16g) (2 mol KMnO4/10 mol FAS) = 2. 530*10-4 mol KMnO4 Flask 3 0. 467g (1 mol FAS/392. 6g) (2 mol KMnO4/10 mol FAS) = 2. 340*10-4 mol KMnO4 Flask 1 (2. 473*10-4 mol KMnO4/0. 02544L) = 0. 00972M Flask 2 (2. 530*10-4 mol KMnO4/0. 02636L) = 0. 00960M Flask 3 (2. 340*10-4 mol KMnO4/0. 02431L) = 0. 00980M Average M = 0. 00971M Flask 1 0. 01809L (0. 00971 mol/1L) = 1. 7565*10-4 mol MnO4- 1. 7565*10-4 mol MnO4- (0. 00971 mol/1L) (5 mol/1 mol) = 8. 78270*10-4 mol Fe2+8. 78270*10-4 mol Fe2+ (55. 85g Fe2+/1 mol Fe2+) = 0. 04905g Fe2+ Flask 2 0. 018171L (0. 00971 mol/1L) = 1. 7643*10-4 mol MnO4- 1. 7643*10-4 mol MnO4- (5 mol/1 mol) (0. 00971mol/1L) = 8. 8215 mol Fe2+ 8. 8215 mol Fe2+ (55. 85g/1 mol) = 0. 492g Fe2+ (0. 04905g Fe2+/0. 286g Fe2+) * 100 = 17. 15% (0. 0492g Fe2+/0. 293g Fe2+) * 100 = 16. 82% 17. 15% + 16. 82% = 33. 97% (33. 97% / 2) = 16. 99% DISCUSSION The results from the lab procedure fully support the lab results expected. If the validity of the lab was non reliable, then the percentage of iron in the iron pills would not be 17%. The results from the lab was 16. 99% which is extremly close to the actual percentage of iron. The results match with the manufacturers stated vcalue of %Fe because the results were over the percentage opticalised by the company by . 31%. There were 389. 5mg in each pill, and 16. 9% of this would be 66. 18mg. Compared to 65mg which was determined by taking 10 pills, weighing them, and dividing by 10, the desired yield was reached. Any mistake in random variable greater than 5% would be a mistake in the titration process or misweighed mass. Titration was used in this lab to oxidize the Fe2+ to Fe 3+ in the FAS, using potassium permanganate solution. It was then used to determine the concentration of Fe2+ in iron pills. The results supported the scientific concept of titration because the process was make mightily and carefully in order to get the closest results to 17% as possible.There was one validity error made in the lab though while the titration process was being done. With flask 2, the stopcock on the buret was not turned parallel to the ground in term and too much KMnO4 was added to the flask. This caused the color to be more of a blank magenta color, instead of a peachy or salmony color kindred flask 1 and 3 were. As explained before, this did not interfere with the results of the percentage of iron in the iron pills, as it was . 01% away from being on the dot correct. It is still a validity error, and needs to be taken into account.For the coterminous time this lab is performed, the person doing the titrating should be extremly careful to do it right and take their time, in order to get the best results possible. (Picture To the left is flask 1, the middle is flask 2 and shows the validity error, and to the right is flask 3. Flask 1 had a unadorned peachy color, flask 2 had a translucent light magenta color, and flask 3 had a translucent salmon color (the lightest). ) CONCLUSION This lab definitely explains how to do a titration, but also gives a hands on know and visual of the chemical reaction of iron oxidizing from Fe2+ to Fe3+.It also gives a hands experience and visual of determining the concentration of Fe2+ in iron pills. This lab was decimal because it refers to how much the amount of the present element or compound on that point is. The theoritical data compares to the experimental data because the theoretical data gave the conclusion that on that point was 17% iron in the iron pills. The experimental results gave a very similar result at 16. 99%. With those results, this lab was a success and brought to the conclusion that even with a small error with the titration, the validity of this lab is very reliable.