A 25.00-mL sample of well water containing dissolved iron was treated with hydroxylamine hydrochloride, pH 5 buffer, and 1,10-phenanthroline, and diluted to 100.0 mL. Absorbances were measured at 510 nm using a 1.00-cm cell. • The prepared sample had an absorbance of 0.584 (all absorbances measured relative to water as reference). • A standard solution prepared in the same fashion, containing 5.00 mL of 5.00 x 10-4 M Fe(ClO4)3 and the reagents (no sample) had an absorbance of 0.284. • The reagent blank had an absorbance of 0.007. Calculate the molar concentration of iron in the original well water sample.