Today I was conducting a redox titration with $\ce{MnO4}$ and unknown amount of $\ce{FeX}$ which through qualitative observation looked like $\ce{FeO(s)}$. I titrated the $\ce{FeX}$(which was dissolved with 10mL $\ce{H2O}$ and 5mL $\ce{H2SO4}$). I had two questions about this experiment:
1) If I am trying to find the molarity of the unknown $\ce{Fe^2+}$ ions (redox reaction), would the increase in volume (mL) of $\ce{MnO4-}$ increase the yield of $\ce{Fe^2+}$ ?
2) When conducting this experiment I did not rely on any indicators yet relied on the $\ce{KMnO4}$ for colour change. I really don't know what the possible sources of error for this experiment are. I need some help trying to come up with 2.
