Please help, This is part of some research I need to do for an elective chem class. Please note, I am taking this as an ONLINE class and have very little instruction and no help. I was able to do some, but I am having problems with the following questions, any help you can give would be wonderful! Thanks, Amy
Redox Titration
Questions:
5. Calculate the percent of iron in the 0.95 gram sample that did not have an overshot endpoint. You will be reporting TWO answers. Use 26.2 ml of KMNO4 for your calculations.
A) Calculate the percent of iron present in a 0.95 gram sample containing iron.
B) Imagine that you ran titration with the iron sample with 0.020 M potassium permanganate, KMnO4 in an acidic solution. The reaction between the iron ion in the sample, Fe2+, and the permanganate ion, MnO4-, is:
8 H+ + MnO4- + 5Fe2+ Mn2+ + 5Fe3+ + 4H2O
We can see from the coefficients in this balanced reaction that it takes 5 iron ions, Fe2+, to react with one permanganate ion, MnO4-. The oxidation half-reaction is:
Fe2+ Fe3+ + e-
The reduction half-reaction is:
8H+ + MnO4- + 5e- Mn2+ + 4H2O
% of iron in sample A:
% of iron in sample B:
6. Imagine that you ran a similar titration using a different iron sample with 0.02 M KMnO4 as the titrant. Calculate the percent of iron in the sample if the sample weighed 0.67 grams, and the volume of the titrant used was 35.7 mL. % of iron in sample:
7.Calculate the percent of iron in a 50.0 gram sample containing iron if 45.6 mL of 2.5 M KMnO4 titrant was used. % of iron in sample:
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