Electrochemical Diagrams Traditional

Because the location of the cathode and the anode as well their polarities (positive and negative) are usually well known, this information may not be shown in the elec-trochanical diagrams. 

While the electrochemical diagrams of the CU/CI2 EC and H2/CI2 GC given previously are very common, they have a serious problem of not showing a three-phase boundary, which commonly occurs in electrochemical cells. A new type of electrochemical diagram is proposed in this book and described here. 

---

Electrochemical diagrams show the materials (chemicals) and phases of electrochemical cell. The traditional diagrams have some challenges, so a new type of diagrams is suggested in this book. 

If an electrochemical cell consists of an SHE and a Ag/AgCl electrode imbedded in the same solntion of HCl(aq), that is, a cell without transfer, then this cell is called the Harned cell. The Hamed cell can be used for measuring the standard thermodynamic properties and mean activity coefficients of HCl(aq) without any complications/uncertainties due to a salt bridge and corresponding diffusion potential in the cell with transfer. The traditional electrochemical diagram of the Harned cell is as follows ... 

Let us estimate E and EP of the Hj/Clj galvanic cell shown in Figure 2.2. The traditional electrochemical diagram... 

The traditional electrochemical diagram for a PEMFC shown in Figure 3.7... 

The traditional electrochemical diagrams cannot properly address the three-phase boundary problem. A new type of electrochemical diagrams is proposed to properly describe the three-phase boundary issue. 

The proposed approach leads directly to practical results such as the prediction—based upon the chemical potential—of whether or not a reaction runs spontaneously. Moreover, the chemical potential is key in dealing with physicochemical problems. Based upon this central concept, it is possible to explore many other fields. The dependence of the chemical potential upon temperature, pressure, and concentration is the gateway to the deduction of the mass action law, the calculation of equilibrium constants, solubilities, and many other data, the construction of phase diagrams, and so on. It is simple to expand the concept to colligative phenomena, diffusion processes, surface effects, electrochemical processes, etc. Furthermore, the same tools allow us to solve problems even at the atomic and molecular level, which are usually treated by quantum statistical methods. This approach allows us to eliminate many thermodynamic quantities that are traditionally used such as enthalpy H, Gibbs energy G, activity a, etc. The usage of these quantities is not excluded but superfluous in most cases. An optimized calculus results in short calculations, which are intuitively predictable and can be easily verified. 

---