From restricted towards realistic models of salt solutions: Corrected Debye–Hückel theory and Monte Carlo simulations

摘要: The properties of bulk salt solutions over wide concentration ranges are explored by a combination simple physical theory and Monte Carlo (MC) simulations. corrected Debye–Huckel (CDH) which incorporates ion size effects in linear response approximation is extended to yield free energy other thermodynamic integration the chemical potential concentration. Charging usually used obtain an electrostatic contribution total electrolytes avoided this new direct approach. MC simulations performed with modified Widom particle insertion method, also provides directly ionic activity coefficients. validity CDH tested comparison simulation data for 1:1, 2:1, 2:2 3:1 restricted primitive model (RPM) range at various sizes. Mean osmotic coefficients calculated RPM electrolyte fitted experimental adjusting only mean diameter. Good fits up 1 molal (m) obtained large number solutions. unrestricted (UPM) 1:1 2:1 varying cation radius while keeping anion fixed crystallographic value. success approach found be specific. For example good 2 3.5 m concentrations were LiCl LiBr, respectively. However case less dissociated salts such as NaCl KI could one Possibility extending applicability >2 including dependent dielectric constant measured experiments. successfully 3 Difficulties encountered simultaneously fitting discussed.