Enthalpies of Solution of Sodium Chloride and Potassium Sulfate in Water. Thermodynamic Properties of the Potassium Sulfate Plus Water System

Published

February 1, 2002

Author(s)

Donald G. Archer, D R. Kirklin

Abstract

An adiabatic calorimeter was used to measure enthalpies of solution into water of sodium chloride ({equal to or nearly equal to} 0.13 mol.kg^-1) at nominal temperatures of 298.15 K, 303.15 K, and 308.15 K and of potassium sulfate ({equal to or nearly equal to} 0.039 mol. Kg^-1) at nominal temperatures of 298.15 K and 303.15 K. The results of sodium chloride were compared to a previous equation of state so as to validate the use of values from that equation of state for calibration of, or checks on the accuracy of, solution calorimeters. Thermodynamic properties from the literature for the potassium sulfate + water system and the present measurements were used to generate equations that represented the thermodynamic properties of this system from the freezing point of the aqueous solution to 500 K. The measured values included in the fitted equations spanned the range of temperature of approximately 271 K to 530 K for K₂SO₄ (aq) and 13 K to 854 K for K₂SO₄ (cr). New equations and/or values for the following properties are given in the present work: 1)thermal properties of K₂SO₄ (cr) from 0 K to near the orthorhombic to hexagonal transition at 857 K, 2) the change in chemical potential for both K₂SO₄ and H₂O in K₂SO₄ (aq) as a function of temperature and molality, valid from 271 K to 500 K, 0 mol.kg^-1 to the saturation molality, and to pressures of 40 Mpa and 3) standard-state properties for the aqueous solution process.

Citation

Journal of Chemical and Engineering Data

Volume

47

Issue

No. 1

Pub Type

Journals

Keywords

enthalpy of solution, potassium sulphate, sodium chloride, thermodynamic properties

Citation

Archer, D. and Kirklin, D. (2002), Enthalpies of Solution of Sodium Chloride and Potassium Sulfate in Water. Thermodynamic Properties of the Potassium Sulfate Plus Water System, Journal of Chemical and Engineering Data (Accessed November 8, 2024)