Posted by Fai on Sunday, January 27, 2013 at 3:23pm.
5Fe^2+ + MnO4^- ==> Mn^2+ + 5Fe^3+
mols FeSO4 = g/molar mass FeSO4
mols KMnO4 = 5 times that (look at the coefficients in the balanced equation)
M KMnO4 = mols KMnO4/L KMnO4. You know mols and M, solve for L and convert to mL.