The stability constant of Pd-EDTA.
The literature value of the stability constant of the palladium-ethylenediaminetetra-acetate complex (log K(Pd-EDTA) = 18.5), is open to question. From replacement experiments with thorium a value log K(Pd-EDTA) = 26.4 has been found. This value is in better agreement with experimental facts from protonation studies at low pH and with the fact that excess of EDTA can be back-titrated in presence of Pd-EDTA at pH 1-2 with ions such as Bi(3+), Tl(3+) and Th(4+). Some preliminary results are given for ternary complex formation between Pd(2+), EDTA and Cl(-).
Kragten
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Natuurkundig Laboratorium, Universiteit van Amsterdam, Valckenierstraat 65, Amsterdam-C, The Netherlands.