COMPLEXING OF Ca(II), Co(II), AND Zn(II) BY POLYMETHACRYLIC AND POLYACRYLIC ACID.

An experimental method proposed for the accurate estimate of the nonideal behavior of metal ions in the course of their complexation by polyacids has been shown to be valid. This nonideal behavior, due to the large and variable electrical field at the surface of the polyelectrolyte in the polyion domain, is ascertained from direct examination of the nonideality of mobile hydrogen ions during potentiometric examination of the competing polyacid dissociation reaction. As a consequence of this approach, it has been possible to show that the dominant complex species in Ca(II) - , CO(II) - , and Zn(II) - polymethacrylic (PMA) and polyacrylic (PAA) acids is an ion pair. The respective formation constants of the ion-pair species have been determined.