Chapter 5, Problem 65E

An iron ore sample weighing0.6132 g dissolved HCl(aq), and the iron is obtained as ${\text{Fe}}^{\text{24}}\left(\text{aq}\right)$ . This solution is then titrated with 28.72 mL of $\text{0}{\text{.05051 M K}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}\text{.}$ What is the mass percent Fe in the ore sample?
${\text{6Fe}}^{\text{2+}}{\text{+14H}}^{\text{+}}{\text{Cr}}_{\text{2}}\to {\text{6Fe}}^{\text{3+}}{\text{+2Cr}}^{\text{3+}}{\text{+7H}}_{\text{2}}\text{O}$