The 3.33 gram sample of iron ore is distorted to a solution of iron (II) sulfate and this solution is titrated with the 0.150 M potassium dichromate. It is needed 41.4 mL of potassium dichromate solution to titrate with the iron (II) solution, calculate the percentage of iron in the ore?
Fe]2+ + CrO7]2- >>> Fe]3+ +Cr]3+