A 3.33-g sample of iron ore is transformed to a solution of iron(II) sulfate, FeSO4, and this

Question:

A 3.33-g sample of iron ore is transformed to a solution of iron(II) sulfate, FeSO4, and this solution is titrated with 0.150 M K2Cr2O7 (potassium dichromate). If it requires 43.7 mL of potassium dichromate solution to titrate the iron(II) sulfate solution, what is the percentage of iron in the ore? The reaction is
6FeSO4(aq) + K2Cr2O7(aq) + 7H2SO4(aq) →
3Fe2(SO4)3(aq) + Cr2(SO4)3(aq) + 7H2O(l) + K2SO4(aq)