Eric J. Reardon Niel Plummer Eurybiades Busenberg Pierre D. Glynn 1992 <p><span>In reply to the Critical Comment of R. K. Stoessell (this issue), limiting activity coefficients of bromide in halite (</span><i>γ</i>_<i>NaBr</i><span>) have been calculated by least-squares fitting of </span><span class="small-caps">Simons</span><span> et al.'s (1952) bromide distribution coefficient data for the Na(Cl,Br)-NaOH-H</span>₂<span>O system at 35°C. Regular and subregular solidsolution model fits give </span><i>γ</i>_<i>NaBr</i><span> = 7.4 and </span><i>γ</i>_<i>NaBr</i><span> = 8.8, respectively. The Br contents of halite at equilibrium with seawater at initial halite saturation, calculated from the regular and subregular fits, are 17 ppm and 14 ppm, respectively. A survey of literature data for trace bromide in halite shows a wide spread in distribution coefficients, with lower values (</span><i>D</i>_<i>Br</i><span>≈ 0.01) reported by </span><span class="small-caps">Bloch</span><span> and </span><span class="small-caps">Schnerb</span><span> (1953), </span><span class="small-caps">Puchelt</span><span> et al. (1972), and </span><span class="small-caps">Lutz</span><span> (1975), and higher values (</span><i>D</i>_<i>Br</i><span>− ≈ 0.03) reported by </span><span class="small-caps">Braitsch</span><span> and </span><span class="small-caps">Herrmann</span><span> (1963), </span><span class="small-caps">Kühn</span><span> (1968), </span><span class="small-caps">Herrmann</span><span> (1972), </span><span class="small-caps">Herrmann</span><span> (1980), </span><span class="small-caps">Mccaffrey</span><span> et al. (1987), </span><span class="small-caps">valiashko</span><span> et al. (1976), </span><span class="small-caps">Valiashko</span><span> and </span><span class="small-caps">Lavrova</span><span> (1976), and Fontes (pers. commun., 1990). The measurement of stoichiometric saturation states for halite (or sylvite) with trace bromide mole-fractions is not practical, given the insensitivity of the measured solubilities on the bromide mole-fractions. Distribution coefficient measurements, with proof of thermodynamic equilibrium, need to be obtained instead, to conclusively determine the thermodynamic-mixing properties of both Na(Cl,Br) and K(Cl,Br) solidsolution series at very low mole-fractions of bromide. The applicability of the stoichiometric saturation concept to the interpretation of precipitation processes is questionable, primarily because the concept requires solid-solutions to behave as one-component solids with fixed composition. Lippmann diagrams are useful in depicting stoichiometric saturation, endmember saturation, and thermodynamic equilibrium states in binary-solid-solution aqueous-solution systems. Lippmann diagrams can contribute a better understanding of these systems, regardless of the concentration of the endmember components.</span></p> application/pdf 10.1016/0016-7037(92)90210-A en Elsevier Reply to Dr. Stoesselfs comment on “Reaction paths and equilibrium end-points in solid-solution aqueous-solution systems” article