Scholarlink

Abstract <p>The liquid–solid and liquid–vapor phase equilibria in the oxalic acid (H<sub>2</sub>Ox)–citric acid (H<sub>3</sub>Cit)–water system at a temperature of 298.15 K (25°C) and 298.15–308.15 K, respectively, are studied. The stability regions of the H<sub>3</sub>Cit⋅H<sub>2</sub>O and H<sub>2</sub>Ox⋅2H<sub>2</sub>O crystalline hydrates are determined. Experimental data on water activity for solutions of the oxalic acid–citric acid–water ternary system are obtained; the saturated vapor pressure above solutions of the H<sub>3</sub>Cit–H<sub>2</sub>Ox–H<sub>2</sub>O system is measured by the static method; water activity is determined by the dew point method. It is shown that water activity depends on temperature only slightly in a temperature range of 298.15–308.15 K. The solubility products of H<sub>3</sub>Cit⋅H<sub>2</sub>O and H<sub>2</sub>Ox⋅2H<sub>2</sub>O are calculated using the Pitzer model. A model that describes the thermodynamic properties of solution and phase equilibria in the H<sub>3</sub>Cit–H<sub>2</sub>Ox–H<sub>2</sub>O ternary system with an accuracy that is not inferior to the experimental accuracy is developed.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Phase Equilibria and Thermodynamic Properties in the Oxalic Acid–Citric Acid–Water System

  • 期刊论文

  • 发表日期：

    2025年10月28日

查看全文
  • Luo Yongxu,
  • A. A. Novikov,
  • S. V. Kurdakova,
  • E. V. Belova,
  • I. A. Uspenskaya

摘要

Abstract

The liquid–solid and liquid–vapor phase equilibria in the oxalic acid (H2Ox)–citric acid (H3Cit)–water system at a temperature of 298.15 K (25°C) and 298.15–308.15 K, respectively, are studied. The stability regions of the H3Cit⋅H2O and H2Ox⋅2H2O crystalline hydrates are determined. Experimental data on water activity for solutions of the oxalic acid–citric acid–water ternary system are obtained; the saturated vapor pressure above solutions of the H3Cit–H2Ox–H2O system is measured by the static method; water activity is determined by the dew point method. It is shown that water activity depends on temperature only slightly in a temperature range of 298.15–308.15 K. The solubility products of H3Cit⋅H2O and H2Ox⋅2H2O are calculated using the Pitzer model. A model that describes the thermodynamic properties of solution and phase equilibria in the H3Cit–H2Ox–H2O ternary system with an accuracy that is not inferior to the experimental accuracy is developed.