SUBSOLUTIONS IN MULTICOMPONENT SYSTEMS: APPLICATIONS TO SOME TERNARY AQUEOUS ACID SULFATE SYSTEMS AT UNIVARIANCE

Abstract

A method is described by which univariant composition data for multicomponent solutions may be tested for consistency or accuracy, and used to estimate or verify invariant points, by reference to the vapor pressure data for an appropriate binary subsolution derived from the system. A subsolution is defined as any homogeneous part of a multicomponent solution, such that it is composed of a smaller number of the components than the total but in which the relative masses of these components are the same as in the parent solution.Published data for ternary systems containing sulfuric acid, water, and the metal sulfates MnSO4, FeSO4, ZnSO4, BeSO4, Na2SO4, and CuSO4 are examined. Some new data for the CuSO4 system are also presented. The subsolution in each case is the binary H2SO4–H2O solution, for which adequate vapor pressure data are available.