Posted by Angel on .
Oh goodness, I'm such a pain! I need some help with these! How do I calculate the percentage? How do I start it?
2. 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:
3. 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:
4. Explain why an overshot endpoint is not a good titration.
The first two questions require me to look at some online interactive lab, but if I know how to do these, I'll be able to do those as well!
Thanks,
Angel

Redox Titration questions! 
DrBob222,
#1.I presume this is titrating Fe(II) to Fe(III).
Write the equation and balance it.
KMnO4 + 5Fe^+2 ==> 5Fe^+3 + Mn+2
You should balance the remainder of the equation.
mols KMnO4 used = M x L = ??
Convert mols KMnO4 to mols Fe by using the coefficients in the balanced equation.
mols Fe = mols KMnO4 x (5 mols Fe^+2/1 mol KMnO4) = ??
Convert mols Fe to grams Fe.
grams = mols Fe x molar mass Fe.
Convert grams Fe to percent.
percent Fe in sample = [grams Fe/mass sample]*100
#2. Worked the same way.
#3. You had the same question last night and I told you to think about it. You WANT to stop at the exact equivalence point. What would undershooting or overshooting the equivalence point mean? 
Redox Titration questions! 
Angel,
Thank you! Oh, question 4 is fine, I just accidentally copied it with the rest of the questions it's repeated in this assignment too. Okay, I'll try and get this!

Redox Titration questions! 
keke,
Explain Why an overshot endpoint is not a good titration.?

Redox Titration questions! 
Yoojin Lee,
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. Could you help me with solving this question? I'm confused.