Polarographic study of the mixed complexes of Cd(II) with oxalate and malonate ions

Abstract

The coordinated mixed Cd(II)-oxalate-malonate system has been polarographically studied in aqueous medium. The ionic strength has been maintained constant at μ = 1.0 mol l^-1 by using NaClO₄. The overall stability constants, determined by using the Schaap and McMasters method, for the coordinated species [Cd(ox)(mal)]^2-, [Cd(ox)(mal)₂]^4- and [Cd(ox)₂(mal)]^4- are respectively β₁₁ = 1.3 . 10⁴ l² mol^-2, β₁₂ = 5.0 . 10⁴ l³ mol^-3 and β₂₁ = 8.7 . 10⁴ l³ mol^-3. The various coordination equilibria are discussed on the basis of statistical aspects.