The percentage of iron in an ore can be established by titration. The iron ore is dissolved in chlorhydric acid, iron is reduced to $Fe^{2+}$ which in turn is titrated by potassium permanganate. Knowing that 38.37 mL of a solution of 0.0198 M permanganate is needed to react wholly with 0.6128 g iron ore, it is asked to calculate the percentage of iron in the ore. $MnO_4^-$ $+$ $5Fe^{2+}$ $+$ $..$ $\longrightarrow$ $..$