Authors: Joseph A Rard Simon L Clegg Donald A Palmer
Publish Date: 2007/10/06
Volume: 36, Issue: 11-12, Pages: 1347-1371
Abstract
Isopiestic vaporpressure measurements were made for Li2SO4aq from 01069 to 28190 mol⋅kg−1 at 29815 K and from 01148 to 27969 mol⋅kg−1 at 32315 K with NaClaq as the reference standard Published thermodynamic data for this system were reviewed recalculated for consistency and critically assessed The present results and the more reliable published results were used to evaluate the parameters of an extended version of Pitzer’s ioninteraction model with an ionicstrength dependent thirdvirial coefficient as well as those of the standard Pitzer model for the osmotic and activity coefficients at both temperatures Published enthalpies of dilution at 29815 K were also analyzed to yield the parameters of the ioninteraction models for the relative apparent molar enthalpies of dilution The resulting models at 29815 K are valid to the saturated solution molality of the thermodynamically stable phase Li2SO4⋅H2Ocr Solubilities of Li2SO4⋅H2Ocr at 29815 K were assessed and the selected value of msat=313±004 mol⋅kg−1 was used to evaluate the thermodynamic solubility product K sLi2SO4⋅H2O cr 29815 K = 262±019 and a CODATAcompatible standard molar Gibbs energy of formation Δf G m o Li2SO4⋅H2O cr 29815 K = −15646±05 kJ⋅mol−1
Keywords: