% Mgo Determination

Vu Ngo % MgO Determination September 10, 2012 Procedure Reference to lab manual information Mass of Na2EDTA2H2O, g . 9289 Standardization of EDTA Solution Trial 1 Trial 2 Final burette reading, EDTA (mL) 18. 5 36. 7 Initial buret reading, EDTA(mL) 0. 5 18. 5 Determination of % MgO of Unknown Unknown act 4J Sample 1 Sample 2 Sample 3 Mass of sample (g) 0. 2135 0. 2132 0. 2139 Final buret reading, EDTA (mL) 73. 5 74. 2 74. 2 Initial buret reading, EDTA(mL) 0. 5 0 0 Measurement of irrigate blank Final buret reading, EDTA(mL) 14. 5 Initial buret reading, EDTA(mL) 14. 2 Sample Calculation habituated Molar mass of Na2EDTA*2H2O, g/mol 372. 25 Expected M of EDTA solution, mol/L (M) 0. 01 minginess of Zn2+, (M) 0. 0125 10mL*1L1000mL= 0. 01L C1V1=C2V2 .0125M. 010L)=C2(. 018L) C2=. 0125M*. 0100L. 0180L=. 00694M .00694M+. 0687M2=. 00691M C2=. 00691M. 073=5. 04*10-4mol %MgO=5. 04*10-4mol40. 05. 2135g*100=9. 51% Results Standardization of EDTA Solution Trial 1 Trial 2 Volume used, EDTA(mL ) 18. 0 18. 2 Molarity of EDTA solution, (M) 0. 00694 0. 00687 Average Molarity of EDTA solution, (M) 0. 00691 Determination of % MgO of Unknown Sample 1 Sample 2 Sample 3 Volume used, EDTA (mL) 73. 74. 2 74. 2 Mole of Mg2+in sample 5. 04E-04 5. 12E-04 5. 12E-04 % of MgO in sample, % 9. 52 9. 69 9. 66 Average % of MgO in sample, % 9. 62 Error Analysis The measurement of the sample in gram, have +/- . 0001g error. The measurement using the the buret have a +/- . 1mL error. These types of measurement error are ground on the sensitivity of the instrument, during the measurement. These errors could cause the firmness of purpose to deviate from the actual answer. During the experiment, using titration to find the determination point. Because of the end point was unknown, a single record could determine its end point.There might be an extra drop that caused the data to vary as two(prenominal) arrays of the experiment have determined. The first trial of both the experiment, the nu mber is different, because of the unsure number of drops. Using the result from the first trial, the result of the second trial was more(prenominal) accurate. As proven from the experiment of determination of percent of MgO of the unknown. The sample 2 and sample 3 interrogation results in similarity that differ from the sample one. The sample used 73. 0 ml of the EDTA solution, while both samples 2 and 3 used 74. 2 ml of EDTA solution.This will cause a tip in the result toward a lower number used to find the end point. This error is not a major factor since it is only of my 1. 2 ml of the actual result. The percent of only three result of MgO is different under 1 percent different. Thus, a very reasonable result in all three of the experiment. Discussion This experiment is to help us understand the reaction between an anion and the metal cation. It show the Lewis base understanding of ethylenediaminetetraacetic acid (EDTA). The goal was achieved through titration of the sample i n multiple trials in piece to find its endpoint.The end point was found when the pink coloration, due to EBT was added, turn into a blue/ empurpled color. This signified its endpoint of the sample. The result is good quality, because of the deviation from the first trial and last trial that was through with(p) on the same sample. The result is off by . 2ml in the standardization of EDTA solution. In the second part of the determination of % MgO of the unknown the first, second, and third sample the percentage displaces is well under 1% difference. The result is cost 99% confident that the result is good quality, because of the consistency of the data.