Ampholyte dissociation theory and properties of ampholyte aqueous solutions

Two different approaches (stepwise and parallel mechanism) for describing the dissociation of amphoteric protolytes are described. Additionally, the classification of the possible model on the basis of the ampholyte lifetime state is proposed. The possibility of application of different schemes is discussed. It is suggested that the correct description may be based only on highly relaxing models. The formulas describing the properties of ampholyte solutions are derived for the case of two ionogenic groups. It is demonstrated that the incorrect choice of the dissociation model may result in essential mistakes in calculation of such values as buffer capacity, electrophoretic mobility, and conductivity. On the basis of the theory here developed, the interpretation of natural pH-gradient conductivity is given. Some terminology questions are also discussed.