A 0. 500 g sample of an impure iron ore is converted entirely into fe2+, which is then titrated with kmno4 (source of mno4- ions) in the following reaction: 5fe2+ + mno4- + 8h+ → 5fe3+ + mn2+ + 4h2o it requires 32. 0 ml of 0. 0200 m kmno4 to react completely with all the fe2+ in the solution. What is the percent by mass of iron in the ore?.