ELECTROCHEMICAL OXIDATION OF MERCURY IN CONTACT WITH BROMIDE AND CHLORIDE IN ACETONITRILE SOLUTIONS

C. DE PAULI,; M. C. GIORDANO; B. LÓPEZ,

JOURNAL OF ELECTROANALYTICAL CHEMISTRY - (Print)

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 1975 vol. 60 p. 81 - 88

1572-6657

Mercury oxidation in presence of bromide and chloride in MeCN solutions has been studied by direct and reverse chronopotentiometry under a wide range of experimental conditions. The reactions follow the same scheme already postulated for iodide solutions with mercury halide complex formation of the type HgXn(2n-1)  The instability constants for the HgX4 (2-) complexes are in the sequence Cl- > Br->I- . Mercury dissolution is facilitated by halide adsorption at the interface. The adsorption sequence is I~ >Br >C1~ and adsorption is enhanced by Et4N + . Thepossibility of ion pairing between the complexing agent and the catión of the supporting electrolyte is analysed to explain the different behavior observed with chloride solutions in presence of Li+ ions.1 C.