Marine Science Faculty Publications

Ultraviolet Spectroscopic Study of Ferric Equilibria at High Chloride Concentrations

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Hydrolysis, ferric chloride, ferric hydroxide, UV spectroscopy, complexes, ion pairs

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The equilibria among the species Fe3+, FeCl2+, FeCl2 +, FeOH2+ and Fe(OH)2 + have been examined by ultraviolet absorption spectroscopy. Our results indicate that previous workers have generally overestimated the stability constant of FeCl2+ and that the association of Fe3+ and Cl is predominantly inner sphere. The formation constant of FeOH2+ obtained in 0.68 m NaCl is in good agreement with our earlier results obtained in 0.68 m NaClO4. Our results indicate that formation of FeOHCl+ is much less significant than has been previously reported. Molar absorptivities for the species Fe3+, FeCl2+, FeCl2 + and FeOH2+ are reported for wavelengths between 220 and 400 nanometers.

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Citation / Publisher Attribution

Journal of Solution Chemistry, v. 10, p. 51-67