Essay About Fe3 And H2C10H

Volumetric Iron Analysis Lab Report
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Lab 7: Volumetric Iron AnalysisAbstract:In this experiment, it was used for determining how much percentage of Fe3+ iron in a sample of ferric iron complex salt. This reaction use with the titration way to slowly added EDTA solution from burette to Fe(HOC6H4COO3)- solution until match an endpoint, which is make Fe(HOC6H4COO3)- solution change color from Intense red-wine color to pale yellow color. In this experiment, it needed to use three closest endpoint(11.5,11.1,10.6) volumes to calculate the mean value and standard deviation of these three closest volumes. Then based on reaction can calculate out the mole value of EDTA and Fe3+, then it could get the mass value of Fe3+ in this complex salt, and using the mass of Fe3+to divide by the salt mass can figure out the how much percentage of Fe3+ iron in this salt. During the calculation, the experiment result below the percent relative standard deviation(%RSD), and from this experiment, it shows the Fe-EDTA bond is stronger than the Fe-indicator bond, because of the solution has color change at endpoint, so the EDTA iron made reaction with Fe3+ iron.Data:EDTA reagent concentration0.02060MMass of ferric salt sample weighted out1.1234gMass of sample transferred in the 25ml pipette0.10414gReplicate titrations of samples in Erlenmeyer flasks(Burette reading in mL)Test 1 Test 2Test 3Final11.822.923.4Initial0.311.812.8Endpoint Volume11.511.110.6Mean of the three closest endpoint volumesV=11.06mLStandard deviation of the three closest endpoint volumes0.4509Millimoles of EDTA in the volume V0.2278Miillimoles of Fe(3) titrated by Vml of EDTA0.2278Mass of Fe(3) titrated by Vml of EDTA0.0127568Percent Fe(3) in the ferric salt12.25%Simple calculation:*100%[pic 1]*100%=12.25%[pic 2]Question:Calculation sample:%RSD=()*100%[pic 3]        %RSD=()*100%=4.07%[pic 4]Due to the percent relative standard deviation is below 0.5%. So the experiment result within the percent error. Which means this experiment data is close to actual data.In this experiment, indicator can determine how much Fe3+ in the ferric mixture. For example, few indication cannot let the solution change color, which is few (H2C10H12N2O8)2- cannot affect Fe(HOC6H4COO3)(aq) solution color. However, when the mole amount of indicator (H2C10H12N2O8)2- match to Fe(HOC6H4COO3)-(aq), the solution from Intense Red-wine color to pale yellow color. If the indicator EDTA((H2C10H12N2O8)2-) were not used in this experiment, that would not get there has any Fe3+ in this solution.The ironic equation should be:Fe(HOC6H4COO3)-+3HOC6H4COO-+2CH3COO-+2H++2Na=2CH3COO-+H2+2Na++ Fe(HOC6H4COO3)-+3HOC6H4COO-Simplify calculation:2CH3COO-+2H++2Na=2CH3COO-+ H2+2Na+ 2H++2Na=2Na++H2Due to the Fe-indicator complex is weaker than the Fe-EDTA-, so when the EDTA met with Fe-indicator could change color like this experiment. However, when the Fe-indicator is stronger than the Fe-EDTA-; it would not change color in general, because the Fe-indicator cannot make react with EDTA solution, so it would not make any color change in this case.Work Cited        Jason J. Evans General Chemistry1, Lab Manual, Third Edition. Print, 2016