Crossing the bridge between thermodynamics and electrochemistry. From the potential of the cell reaction to the electrode potential

Abstract

Thermodynamics plays a similar role in physical chemistry like mathematics in science, however, the inherent link between thermodynamics and electrochemistry is not entirely obvious. Less attention is paid to such physical quantities as pressure, volume, enthalpy, chemical potential etc. in electrochemistry; on the other hand new quantities (charge, current, electric potential etc.) and terms (galvanic cell. electrode, ion etc.) appear. It is the main goal of this lecture to present a systematic thermodynamical treatment regarding the electrochemical cells; and to give the definitions accepted presently for physical quantities, e.g., potential of the cell reaction, electrode potential, electrochemical potential as well as terms such as electrode.

The inherent coupling of charge transfer and mass transport processes: the curious electrochemical reversibility

“…In previous contributions [1,2], we dealt with the thermodynamic and kinetic aspects of redox reactions occurring either by direct contact of the reagents with each other or inside an electrochemical cell. Both the cases of a spontaneous process in a galvanic cell and of a forced one in an electrolytic cell were considered, especially focusing the attention to the oxidation or reduction half-reaction at a single electrode, i.e.…”

“…The second electrode is the so-called auxiliary electrode. In the three-electrode arrangement (three-electrode cell), a reference electrode (RE) is also present, allowing the best control of the potential of the WE [1]. Therefore, we will focus on the events occurring at a single electrode.…”

“…In previous contributions [1,2], thermodynamics and kinetics have been treated 'separately' from the other steps of the whole charge-transfer process. However, whenever electric current crosses the 'electron conductor|electrolyte' interface, the following issues need being considered: (1) How is the reactant transported to the interface and how does the product leave it, i.e.…”

“…However, whenever electric current crosses the 'electron conductor|electrolyte' interface, the following issues need being considered: (1) How is the reactant transported to the interface and how does the product leave it, i.e. what manages the mass transport to and from the electrode surface?…”

Another beauty of analytical chemistry: chemical analysis of inorganic pigments of art and archaeological objects

“…According to the physical or chemical principia in which the method is based, it can be classified into five main groups, as shown in Fig. 8: (a) classical chemical analysis [11,12,28,33,43], (b) spectroscopic techniques [10,11,17,44,45], (c) activation techniques [10,11,19], (d) electrochemical methods [14, [46][47][48][49][50], and (e) thermoanalytical techniques [11,18,51].…”