The “Overlapping Equilibria” Effect in the Processes of the Electrolytic Dissociation of Weak Multibasic Organic Acids

The "overlapping equilibria" effect observed in the processes of electrolytic dissociation of many weak multibasic organic acids determines the character of these processes. In this communication, the degree of "overlapping equilibria" in case of weak dibasic organic acids is quantitatively characterized by the values of "partial" degree of dissociation for second step and ratio of the concentrations of dianion and monoanion. It has been shown that these dissociation parameters are directly connected with the values of the second dissociation constant. It has been also shown that the contribution of third dissociation step in the "overlapping equilibria" effect is especially appreciable in case of penta and hexabasic weak organic acids causing the double "overlapping" phenomenon.