ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Influence of composition of the methanolic-aqueous solvent on properties of the cadmium and chloride ion-selective electrode

M. Mamczák, J. Harvanová, and A. Hanudeľ

Department of Physical and Analytical Chemistry, Faculty of Natural Sciences, P. J. Šafárik university, CS-041 67 Košice

Abstract: The influence of methanolic-aqueous solvent (x_CH3OH=0.1—0.8) on electromotive voltage of the galvanic cell consisting of a cadmium or chloride ion-selective electrode and a saturated calomel electrode has been studied. The electrode potential of the cadmium ion-selective electrode is linearly dependent on composition of the solvent for the solution of 10^-2 M-Cd(Cl0₄)₂ and is governed by the following equation E_cd^ISE = 96.5+131.5x_CH3OH By the method of least squares the standard electrode potentials of the cadmium ion-selective electrode have been calculated. They are linearly dependent on composition of the solvent as follows E°_Cd = 144.8+113 х_снзон The dependence of the standard Gibbs energy of transport of the cad­mium ion from water into methanolic-aqueous solvent at 298 К can be expressed by the following equation ∆G°_tr  = 27 . 9 - 192.3 E°_m where  E°_m is standard electrode potential in a given binary solvent. The Gibbs energy of transport increases with the content of methanol in the solvent.

Full paper in Portable Document Format: 444a519.pdf

Chemical Papers 44 (4) 519–525 (1990)