Some remarks on the titration equation of weak polyacids

Abstract

The titration equation for weak polyacids, derived by Overbeek in 1948 using a specific model for a polyion and making some assumptions on the addivity of conformational and electrostatic free energy, is shown to be generally valid for polyelectrolyte systems in which all intermolecular interactions except electrostatic ones are neglected. The proof is based on a statistical mechanical evaluation of the change in total free energy with degree of ionization.