SPECTROPHOTOMETRIC STUDIES TO DETERMINE THE DISTRIBUTION COEFFICIENT OF SOME METAL IONS ON ANION EXCHANGE RESIN IN PRESENCE OF E.B.T. DYE.

Document Type : Original Article

Authors

Chemistry Dept. Girls, College of Education, P. O. Box 114176, Jeddah – 21381 Kingdom of Saudi Arabia

Abstract

       The absorption spectra of various concentrations of some metal nitrate salts; Co(II), Ni(II), Cu(II) and Cr(III) nitrate, with different concentrations of Eriochrome Black T (E.B.T) dye solutions were studied in the presence and absence of Dowex – S.B.R. anion exchange resin ( nitrate form ) . The calculated values of distribution coefficient kd illustrate the importance of the E.B.T dye solution as complexing agent for the removal of different metal ions on the Dowex – S.B.R. anion exchange resin. The same studies have been performed for samples in different molarities of nitric acid at constant concentration of E.B.T. and metal ion solution for only Co (II ) and Ni ( II ) ions since Cu ( II ) and Cr ( III ) ions precipitate in the presence of E.B.T. The nitric acid imported also a marked influence on Co and Ni ions complex formation and consequently on their kd values. Ethanol and acetone were used in different proportions to evaluate the effect of changing the dielectric constant of the medium on the kd values of the Co and Ni with E.B.T. in the studied solutions. The kd values are markedly higher in acetone – dye – metal ion - water media as compared with those obtained in aqueous – ethanol – dye – metal ion mixture at the same concentrations. The effects of pH on the absorption and kd behavior for Co (II) and Ni (II) ions in presence of E.B.T. dye on the Dowex – S.B.R. anion exchange resin were studied and discussed.

Keywords

Main Subjects