Observable electric potential in a KCl salt bridge

The theoretical description of nonequilibrium electrochemical systems invol ves nonobservable variables such as diffusion potential (dp). In the recent years, a new way based on the observable electric potential (oep) has been developed. In this work we provide an illustration of the potential applic ations of the oep formalism by considering a system of great practical inte rest: the salt bridge. This system has been chosen because, in spite of its widespread use for many decades, a sound theoretical base for the salt bri dge concept is still lacking. The oep is offered as a good alternative in t he salt bridges. Moreover it involves a ternary electrolyte system, with a common anion at uniform temperature and pressure, which complexity is enoug h to make useful this application example of the oep formalism. (C) 2000 Th e Electrochemical Society. S0013-4651(00)02-062-0. All rights reserved.