On the use of cation exchangers for the study of complex systems—II: The systems bismuth (III)-bromide, iodide and fluoride

Abstract

Distribution measurements of bismuth-210, between 1·890 M perchloric acid solution and the cation exchangers Dowex 50W-X8 and X16, were explored as functions of the added HF-, Br −-, and I −-concentrations. For the F- and Br-systems stability constants and distribution coefficients for a number of the complexes could be calculated by a method previously described. (1) For the Br-system we found: β 1 = (2·30 ± 0·05) × 10 2, β 2 = (2·6 ± 0·2) × 10 4, β 3 = (1·8 ± 0·3) × 10 6, β 4 = (5 ± 2) × 10 7, and for the F-system: β 2H = 27 ± 1 and β 2H = 58 ± 4 from which the approximate values β 1 ≈ 5 × 10 4 and β 2 ≈ 2 × 10 8 are calculated. The distribution curves for the Bi 3+I − system, in contrast with the other systems, showed points of inflection. It is suggested that this is caused by absorption of, for example, a negatively charged bismuth-iodide complex. From measurements on the highest cross-linked resin a value of β 1 = 800 ± 200 could be determined for the complex BiI 2+.