Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

The solid-liquid equilibrium (SLE) in the ternary system 2-keto-l-gulonic acid (HKGA) + sodium-2-keto-l-gulonate (NaKGA) + water was studied experimentally at temperatures between 275 and 313 K and ambient pressure. At these conditions, HKGA and NaKGA precipitate as monohydrates: HKGA*H2O and NaKGA*H2O, respectively. Phase diagrams with one eutonic point are found for all temperatures. A thermodynamic model of the SLE that is based on an extended version of the Debye-Hueckel theory was developed and the dissociation constant of HKGA as well as the solubility products of HKGA*H2O and NaKGA*H2O were determined. The agreement between the experimental data and the results from the model is excellent.