Once More About the Analysis of the Ag/AgI Electrode Impedance

The reliability of different electrode admittance equations in the case of the Ag/Ag I electrode is critically discussed. It is shown that the admittance equation already derived for the metal amalgam/metal-Ion reversible electrode reaction coupled with reactant adsorption offers some advantages compared to the admittance equation for the reversible electrode reaction on the metal/metal-ion electrode. New results of impedance measurements of the Ag/Ag I electrode are reported

On the Warburg Parameter of the Ag/AgI Electrode

The possible origins of frequent deviations from the calculated and experimentally obtained values of the Warburg parameter of the Ag/AgI electrode are discussed. Following the considerations of possible conditions for classical Warburg impedance to appear in solid AgI, it is suggested that the overall Warburg impedance of the Ag/AgI electrode could be considered as the sum of the Warburg impedances in series, one in the solid, and the other in the solution phase. In addition, the influence of diffusion controlled adsorption of I- ions in parallel with diffusion controlled ion-transfer on the experimentally obtained values of the Warburg parameter is discussed. A different theoretical approach to the analysis of the Warburg impedance of the Ag/AgI electrode is suggested, different from those formerly applied

Electrochemical Separation of Carrier-free Iron

The separation of vario us e lements by electrodeposition using a mercury cathode has b een presented in a summarised form1 • However, as stated by Lavrukhina such investigations, especially in the case of trace elements, have not been carried out systematically. Hovewer, it is well known that the d eposition of iron group elements onto a Hg-cath ode is followed by an overvoltage. A number of papers3 - 7 present the application of this method to various systems, but a method to be applied for the separation of trace amounts of iron from large amounts of manganese using a constant potential mercury cathode system has not been described as yet

Impedance of Fe80B20 Glassy Alloy in Sulphuric Acid

Experimental investigations of corrosion behavior of glassy metal Fesolfco in 1.0 mol dm"3 H2SO4 are described. Results are presented on voltametric and impedance measurements in three distinct anodic potential ranges. Two relaxation processes have been observed and identified: i) a kinetically controlled interfacial charge transfer mediated by adsorption of some intermediate species in the active dissolution range; ii) the same process, but with a blocking effect due to adsorption of the passivating species in the passivation or transition range; and iii) ion migration in a high electric field within the passive layer with adsorption of surface states in the passive range. Using a general impedance of the resistance, the measured impedances have been characterized in terms of parameters of compatible equivalent circuits

Impedance of Fe80B20 Glassy Alloy in Sulphuric Acid

Experimental investigations of corrosion behavior of glassy metal Fesolfco in 1.0 mol dm"3 H2SO4 are described. Results are presented on voltametric and impedance measurements in three distinct anodic potential ranges. Two relaxation processes have been observed and identified: i) a kinetically controlled interfacial charge transfer mediated by adsorption of some intermediate species in the active dissolution range; ii) the same process, but with a blocking effect due to adsorption of the passivating species in the passivation or transition range; and iii) ion migration in a high electric field within the passive layer with adsorption of surface states in the passive range. Using a general impedance of the resistance, the measured impedances have been characterized in terms of parameters of compatible equivalent circuits