Interaction between hexacyanoferrate(II) ion and mercury(II) and silver(I) ions

Abstract

The interaction between hexacyanoferrate(II) ion and mercury(II) or silver(I) ion was studied conductometrically in aqueous solution. The maximum decrease in conductivity occurred at a 1 : 2 mole ratio of K₄[Fe(CN)₆] : HgCl₂ or at a ca. 1 : 4 mole ratio of K₄[Fe(CN)₆] : AgNO₃. The decrease in conductivity is considered to be due to complex formation between hexacyanoferrate(II) ion and the metal ions. The salt effect on the Hg^II-catalysed dissociation of [Fe(CN)₆]^4– to [Fe(CN)₅H₂O]^3– is positive at low, but negative at high, ionic strength. The mechanism of this reaction is discussed.