The electromotive force of a galvanic cell

As described previously, the galvanic cell is a system constructed from a set of thermodynamic phases such that an electric current can exist and a chemical reaction can proceed in the system. It seems to be a reasonable starting point to describe a system in which two different electrolyte solutions are placed in contact with another. The remaining two boundaries are formed from solid materials and the loop is closed by some inert metal which does not enter in the reaction scheme. Fig. 25 gives a schematic representation of a special system which involves the constituents Na, K, Cl, and I together with water. In Fig.25 the Fig. 25Schematic representation of the galvanic cell described in this section. Here and in the following figures showing galvanic cells, the set up is really drawn as a closed loop. The portion of the loop drawn as a dashed line represents a device making the electric current sufficiently small. galvanic cell has indeed been drawn as a closed loop. This is to remind the reader that the galvanic cell is a device shaped in a particular way in which a chemical reaction proceeds. In the following pages we shall repeatedly give this schematic representation of a galvanic cell as a “reaction vessel”. This is in contrast to the abbreviated form of representation which is commonly used in conventional treatments and also in the heading of this section.