Your question is somewhat lengthy and sorta runs in circles; however, I assume the question boils down to why are you using the average. I think the answer is this.
You may use individual titrations, calculate EACH run for molarity (or whatever you're calculating) and after running say four of these you calculate the average M of the solution. OR you can take the average volume of the titrations and do ONE calculation to find the average M of the solution. I think the idea is that by using the average volume you can save some calculation time.
In lab, I weighed out and found the molarity of 1.108g Na2C2O4 and 1.100g K3Fe(C2O4)3. I titrated an average of 0.0335L of the sodium oxalate solution with KMnO4(potassium permanganate). I then titrated an average of 0.0169L of K3Fe(C2O4)3 X 3H2O with potassium permanganate. I used 2MnO4 + 6H + 5H2C2O4 = 8H2O + 2Mn + 10CO2 for the first stoichiometry part to find out the moles of permanganate ion. I then used 5Fe(C2O4)3 + 6MnO4 + 48H = 5Fe + 6Mn + 30 CO2 + 24 H2O. For the second stoichiometry part to find out the number of moles of K3Fe(C2O4)3. I tried this several different ways, but what I can come up with is that I used the moles/L of sodium oxalate and since the sodium oxalate solution is the same as the oxalic acid which is used in the first formula to find the moles of the permanganate ion which is used in the second formula to find the number of moles of K3Fe(C2O4)3 I reacted.I don't understand and don't know why I have to use my average titrated volumes. Please help. I have reread the lab so many times I cannot wrap my mind around it
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