To determine the concentration of Fe in a given sample of iron ore using the coulometric titration technique with a standard solution of K2Cr2O7, you will need to follow these steps:1. Prepare the sample: Weigh an accurately known mass of the iron ore sample and dissolve it in an appropriate solvent, usually a mixture of hydrochloric acid HCl and water.2. Reduction of iron: Add an excess of tin II chloride SnCl2 to the solution to reduce the iron III ions Fe3+ to iron II ions Fe2+ . This step is crucial because K2Cr2O7 will only react with Fe2+ ions.3. Titration: Titrate the resulting solution with a standard solution of potassium dichromate K2Cr2O7 in the presence of an acidic medium usually sulfuric acid, H2SO4 . The reaction between Fe2+ and Cr2O7 2- ions can be represented by the following balanced equation:6 Fe2+ + Cr2O7 2- + 14 H+ 6 Fe3+ + 2 Cr3+ + 7 H2O4. Endpoint detection: The endpoint of the titration can be detected using an indicator, such as diphenylamine or an amperometric method.5. Calculation: Once you have reached the endpoint, note the volume of the K2Cr2O7 solution used. Use the stoichiometry of the reaction and the concentration of the K2Cr2O7 solution to calculate the moles of Fe2+ in the sample. Then, use the mass of the iron ore sample to determine the concentration of Fe in the sample.Here's the formula to calculate the concentration of Fe in the sample:Concentration of Fe in g/g = Moles of Fe2+ * Molar mass of Fe / Mass of iron ore sampleRemember to convert the concentration to the desired units, such as percentage % , parts per million ppm , or any other unit as required.