ChemInform Abstract: Cyanide Thermodynamics. Part 4. Enthalpies and Entropies of Cyanide Complexation of CuI, AgI, ZnII, and CdII.

Abstract

1996 thermodynamic functions, thermochemistry thermodynamic functions, thermochemistry E 3000 -008Cyanide Thermodynamics. Part 4. Enthalpies and Entropies of Cyanide Complexation of CuI, AgI, ZnII, and CdII. -Enthalpies of complexation by cyanide of the title metal ions in both aqueous NaCl and NaClO4 media at an ionic strength of 1 mol/l at 25 . degree.C are determined by titration calorimetry. Entropy changes associated with the complexation are obtained by combining the present δH data with the appropriate δG (stability constant) data from the literature. The δH values show little dependence on the medium. The considerable variation of the δS values is attributed to competitive complexation of some of the metal ions by Cl-. The great stability (negative δG values) for the formation of cyanide complexes in aqueous solution is due to the highly favorable . delta.H term as δS is negative. -(SOLIS, J. S.; MAY, P. M.; HEFTER, G.; J. Chem. Soc., Faraday Trans.: Phys. Chem.