Molar Volume of Molten Binary CaCl₂-NaCl, LaCl₃-NaCl, and LaCl₃-CaCl₂ and Ternary LaCl₃-CaCl₂-NaCl Systems

Abstract

Molar volumes of molten CaCl 2 -NaCl, LaCl 3 -NaCl, LaCl 3 -CaCl 2 and the quasi-binary systems LaCl 3 -nNaCl · mCaCl 2 (mole ratio n : m = 1:3.2, 1:1, and 2.6:1) have been measured by the dilatometric method, and expressed as functions of both temperature and mole fraction by means of least squares regression. The molar volumes of molten LaCl 3 -NaCl and LaCl 3 -CaCl 2 showed positive and negative deviations, respectively, from additivity, while CaCl 2 -NaCl and the three quasi-binary systems satisfied approximately the additivity. The isotherm of molar volume for ternary LaCl 3 -CaCl 2 -NaCl system at 900 °C was represented according to the isotherms of three binary and three quasi-binary systems.