A 10 cm aliquot of a Fe³⁺ unknown is diluted to 50 cm. A 5 cm portion of this solution is then treated with 1,10-phenanthroline; the resulting complex ion has an absorbance of 0.233 at 512 nm. A 2.2 x 10-S M standard solution of Fe treated with the same chelating agent has an absorbance of 0.577 at the same wavelength, in a cell of the same path length. Calculate the molarity of Fe+ in the 10 cm aliquot of unknown.+
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