ELECTROCHEMICAL STUDY OF THE PROPERTIES OF IRON IONS IN ZNCL2-DEGREES-C(2NACL MELT AT 450)

The electrochemical properties of Fe(II) in the ZnCl2 + 2NaCl melt at 450 degrees C have been studied using a glassy carbon electrode. Iron oxidation states II and III have been shown to exist in the mixture an d the stability of metallic iron has been confirmed. The kinetics of t he electrodeposition and electrocrystallization of iron were studied f inding that the process is quasi-reversible. In the same way, the Fe(I II)/Fe(II) exchange was found to be quasi-reversible. The values of th e kinetic parameters, k(o) and alpha for both reactions were obtained. Mass transport towards the electrode is a simple diffusion process. T he diffusion coefficient was found (1.3 +/- 0.4) X 10(-5) cm(2) s(-1). Potential step measurements indicate instantaneous nucleation and gro wth of iron (I against t(1/2)) followed by diffusion control (Cottrell equation).