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
See you post above under a different screen name. Don't screw things up by using different screen names.
In this lab, you weighed out samples of sodium oxalate (Na2C2O4) and potassium ferric oxalate (K3Fe(C2O4)3) and performed titration experiments with potassium permanganate (KMnO4) to determine their molarities.
To start, you calculated the moles of permanganate ion (MnO4-) that reacted with the sodium oxalate using the balanced equation:
2MnO4- + 5H2C2O4 + 6H+ --> 2Mn2+ + 10CO2 + 8H2O
To do this, you utilized the fact that 1 mole of permanganate ion reacts with 5 moles of oxalic acid. By knowing the volume of sodium oxalate solution (0.0335 L) and the molarity of the permanganate solution, you were able to determine the number of moles of permanganate ion that reacted.
Similarly, you used the second balanced equation:
5Fe(C2O4)3 + 6MnO4- + 48H+ --> 5Fe2+ + 6Mn2+ + 30CO2 + 24H2O
To find the number of moles of potassium ferric oxalate (K3Fe(C2O4)3), you needed the number of moles of permanganate ion used in the titration with K3Fe(C2O4)3. By knowing the average volume of K3Fe(C2O4)3 solution titrated (0.0169 L) and the molarity of the permanganate solution, you could calculate the moles of permanganate ion.
The reason you used the average titrated volumes is to improve the accuracy of your calculations. Typically, multiple measurements are taken to account for any random errors that may occur during the titration process. Taking the average of these volumes helps minimize the impact of any outliers and provides a more reliable value for your calculations.
In summary, by using stoichiometry and the volumes of solutions titrated, you were able to determine the moles of permanganate that reacted with both sodium oxalate and potassium ferric oxalate. From there, you can use the moles of sodium oxalate to determine the moles of potassium ferric oxalate using the stoichiometry of the balanced equation.
I hope this explanation helps you understand the reasoning behind the calculations in the lab. If you have any further questions, feel free to ask!