SIMULTANEOUS DETERMINATION OF EQUIVALENCE VOLUMES AND THERMODYNAMIC ACID DISSOCIATION-CONSTANTS FROM DATA FOR THE ACIDIC REGION OF POTENTIOMETRIC TITRATION CURVES

New iterative methods for the analysis of potentiometric titration dat a of weak monoprotic acids or of mixtures of two monoprotic acids are presented. These methods, using equations without approximations and d ata exclusively resulting from the acidic region of the titration curv e, seem to be valid throughout the acidic strength range. In the titra tion of weak monoprotic acids, the proposed procedures are able to ext ract accurate values of the equivalence volume and also the thermodyna mic dissociation constant. On the other hand. in the titration of mixt ures of two monoprotic acids, the proposed approach is able to extract accurate values of the concentrations and the thermodynamic dissociat ion constants of the component acids even when their acidity strengths are similar. The test of the proposed procedures by means of ideal si mulated data (free from any extraneous ''noise'') and Monte Carlo simu lated data revealed that these methods are fairly applicable even when the titration data are considerably obscured by ''noise''. Further, f or acids having pK greater-than-or-equal-to 4 the proposed procedures lead to accurate results even when the pH data contain an important sy stematic error. The proposed procedures were also successfully applied to experimental titration data for weak acids. A procedure for the an alysis of titration data carried out in binary water-dimethylformamide solvent systems is also presented.