7) A 3.33 g sample of iron ore is transformed into a solution of iron (II) sulfate. And this solution is titrated with 0.0150 M potassium dichromate. If it requires 41.40 mL potassium dichromate solution to titrate the FeSO4, find the percentage of iron in the ore? The mole ratio between FeSO4 and K2Cr2O7 is 6 to 1.