A compound contains only Fe and O. A 0.2729 g sample of the compound was dissolved in 50 mL of concentrated acid solution, reducing all the iron to Fe2+ ions. The resulting solution was diluted to 100 mL and then titrated with a 0.01621 M KMnO4 solution. The unbalanced chemical equation for reaction between Fe2+ and MnO−4 is given below. MnO−4(aq)+Fe2+(aq)→ Mn2+(aq)+Fe3+(aq) (not balanced) The titration required 42.17 mL of the KMnO4 solution to reach the pink endpoint.