How to solve: A solution of K2Cr2O7 is standardized againstFe(NH4)2(SO4)2 6H20. Exactly 0.625g of the iron salt are equivalentto 22.5 mL of the dichromate solution. A sample of unknown iron(II) is then titrated with the dichromate. Exactly 25.0 mL of theiron are equivalent to 18 mL of the K2Cr2O7 solution. Calculate thenumber of millimoles of iron per mL of unknown solution. The answeris 2.98 mg/mL
