Collect. Czech. Chem. Commun. 1999, 64, 1925-1936

Adsorption of Iodide Ion from Aqueous NaI-NaClO4- Butan-1-ol at the Mercury-Electrolyte Interface

Jadwiga Saba*, Kazimierz Sykut, Jolanta Nieszporek and Jan Szaran

Faculty of Chemistry, M. Curie-Skłodowska University, 20031 Lublin, Poland


Properties of the adsorption layers I--ClO4--H2O and I--ClO4--H2O-butan-1-ol on the mercury electrode were described using adsorption and kinetic parameters for the Zn(II) ion reduction. The systems were characterized by the measurements of differential capacity, zero charge potential and surface tension at this potential. The data were analysed to obtain the surface pressure and the charge due to specific adsorption of I- ions as a function of charge and concentration of I- ions. The standard Gibbs energy of adsorption ∆G0ad and parameter B obtained from the virial isotherm were compared. The rate constants of Zn(II) ion reduction as an ion affecting the adsorption equilibrium were determined.

Keywords: Mixed adsorption layer; Electroreduction Zn(II) ions; Polarography; Electrochemistry.