Crystal structure and thermochemical properties of potassium pyruvate C_lus-plus">3H_lus-plus">3O_lus-plus">3K(s)

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• 作者：You-Ying Di ; Yu-Han Zhang ; Yu-Xia Kong…
• 关键词：Potassium pyruvate ; Crystal structure ; Pitzer theory ; Molar enthalpy of dissolution at infinite dilution ; Enthalpy of hydration
• 刊名：Journal of Thermal Analysis and Calorimetry
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：127
• 期：2
• 页码：1523-1532
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Physical Chemistry; Analytical Chemistry; Polymer Sciences; Inorganic Chemistry; Measurement Science and Instrumentation;
• 出版者：Springer Netherlands
• ISSN：1588-2926
• 卷排序：127

文摘

One important compound potassium pyruvate C₃H₃O₃K(s) is synthesized and characterized by chemical analysis, elemental analysis, and X-ray crystallography. X-ray single-crystal structural analysis reveals that the compound is formed by one CH₃COCOO− anion and one metal cation K+. An obvious feature of the crystal structure of the compound is the formation of the five-membered chelate ring, and it is good for the stability of the compound in structure. The lattice potential energy of the compound and ionic volume of the anion CH₃COCOO− are obtained from crystallographic data. The lattice potential energy is determined to be: U_POT[C₃H₃O₃K(s)] = 567.7 kJ mol−1. The V₋ (the volume of the anion CH₃COCOO−) is estimated to be 0.088 nm3. Molar enthalpies of dissolution of the compound at various molalities in the double-distilled water are measured by use of an isoperibol solution-reaction calorimeter at 298.15 K. According to Pitzer’s electrolyte solution theory, molar enthalpy of dissolution of C₃H₃O₃K(s) at infinite dilution is derived to be 22.9 kJ mol−1. The values of relative apparent molar enthalpies (ΦL), relative partial molar enthalpies (\( \bar{L}_{2} \)) of the compound, and relative partial molar enthalpies (\( \bar{L}_{1} \)) of the solvent (water) at different concentrations m/(mol kg−1) are derived from the experimental values of the enthalpies of dissolution of the compound. Finally, the molar enthalpy of hydration of the anion CH₃COCOO−(g) is calculated to be −227.8 kJ mol−1 by the design of the thermochemical cycle.