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Sean MurphyGroup 3Dr. WeiDetermination of Fe by UV-Vis SpectrometryIntroduction:A complex of iron (II) is formed with 1,10-phenanthroline, Fe(C12H8N2)32+, and the absorbance of this colored solution is measured with a spectrophotometer. The spectrum is plotted to determine the absorption maximum. Hydroxylamine (as hydrochloride salt to increase solubility) is added to reduce Fe3+ to Fe2+ and to maintain it in that state.4 Fe3+ + 2NH2OH → 4Fe2+ + N2O + 4H+ + H2OMaterials:•1, 10-Phenanthroline solution•Standard iron (II) stock solution•Hydroxylammonium chloride solution•Sodium acetate solution•Unknown: 12mL for each group•Volumetric Flasks•5, 10, and 25mL volumetric pipetsProcedure:1.Into each of the five 100mL volumetric flasks, pipet 5, 10, 15, 20, and 25 mL of the standard iron (II) stock solution into the flasks.2.Pour 50mL of DI-water into a 6thflask to serve as the “blank”.3.Obtain 12mL of the unknown sample, place in a 7thflask and treat it in the same manner as the standards.