Application of Pitzer's equations to dissociation constants of ammonium ion in lithium chloride–sodium chloride mixtures

Abstract

The Pitzer equations have been used to calculate the dissociation constants of NH⁺₄ ions in concentrated LiCl–NaCl solutions at 25 °C. The calculated values agreed with the observed values within experimental uncertainties provided all the higher-order interaction terms (θS and ψS) concerned were introduced. The θ(NH₄Na) and ψ(NH₄NaCl) values, which are not available in the literature, were determined from isopiestic measurements of NH₄Cl–NaCl solutions.