Steady-state electrolysis of an ampholyte solution and possibility of violation of the "law of pH monotony"

The problem of stationary electrolysis of a single-component ampholyte solution is analyzed. The effect of nonconstant relative mobility is taken into account. It is demonstrated that an incorrect dissociation model (i.e., expressing the resulting ampholyte flux by the arithmetic sum of the fluxes for "cationic" and "anionic" species) may lead to the violation of the so-called "law of pH monotony".