The Individual Activity Coefficients of a Solvent Primitive Model Electrolyte Calculated from the Inverse Grand-Canonical Monte Carlo Simulation and MSA Theory

Stanisław Lamperski (1) , Monika Płuciennik (2)

1 UAM - Uniwersytet im. Adama Mickiewicza w Poznaniu = Adam Mickiewicz University in Poznań
2 Faculty of Chemistry

The recently developed inverse grand-canonical Monte Carlo technique (IGCMC) [S. Lamperski. Molecular Simulation, 33, 1193 (2007)] and the MSA theory are applied to calculate the individual and mean activity coefficients of ions and solvent for a solvent primitive model (SPM) electrolyte. In the SPM electrolyte model the anions, cations and solvent molecules are represented by hard spheres immersed in a dielectric continuum whose permittivity is equal to that of the solvent. The ions have a point electric charge embedded at the centre. A simple 1:1 aqueous electrolyte is considered. The ions are hydrated while the water molecules form clusters modelled by hard spheres of the diameter ds. The diameter ds depends on the dissolved salt and is determined by fitting the mean activity coefficient lnγ± calculated from IGCMC and from the MSA to the experimental data. A linear correlation is observed between ds and the Marcus parameter ΔGHB which describes the ion influence on the water association.

Mots clés: Physical Sciences

Stanisław Lamperski, Monika Płuciennik. The Individual Activity Coefficients of a Solvent Primitive Model Electrolyte Calculated from the Inverse Grand-Canonical Monte Carlo Simulation and MSA Theory. Molecular Physics, 2011, 109 (01), pp.49-54. ⟨10.1080/00268976.2010.544264⟩. ⟨hal-00661252⟩