Densities and apparent molar volumes of aqueous NaCl–KBr mixtures at 298.15 K

Abstract

Experimental differences in densities Δd of aqueous NaCl–KBr mixtures at I = 1, 2, 3, and 4 mol kg−1 and at 298.15 K are reported from pure NaCl to pure KBr solutions. Mean apparent molar volumes [Formula: see text] are calculated and excess volumes of mixing [Formula: see text] are correlated by Friedman equation, Δd and [Formula: see text] are analysed in terms of recently developed the Pitzer formalism without and with mixing terms. Pitzer equations can estimate the densities of such mixtures with uncommon cations and anions within ±0.02% at the high ionic strength of 4 mol kg−1.