摘要

Liquid water has a density maximum at T (max)(H2O) = 277.13 K, and around this temperature the structure of the liquid changes significantly. In order to investigate the impact of such an unusual solvent density behavior upon the temperature dependence of Henry fugacities (also known as Henry's law constants) and related quantities of aqueous solutions of gases, that is, in particular, in order to solve the question of the existence of a point of inflection in curves vs. T near T (max)(H2O), we use results of high-precision gas solubility measurements in water of He, Ne, Ar, N-2, and O-2, where data have been reported for reasonably large and reasonably fine temperature grids around T (max)(H2O). Focusing on the temperature region , the discussion is essentially based on analysing difference quotient plots vs. . These plots summarize solubility results obtained at adjacent temperatures and , with being the average temperature, and are closely related to plots of vs. , with being the partial molar enthalpy change on solution of the gas in water. The question is essentially resolved through including in the discussion insight gained from calorimetrically determined enthalpies of solution, i.e., through use of high-precision results obtained from flow-calorimeters originally designed by Gill and Wadso in 1982 and 1984, respectively. Careful analysis of experimental results accumulated so far on the temperature dependence of the Henry fugacity around T (max)(H2O) and on corresponding enthalpies of solution do not support any unusual behavior of in this temperature region.

  • 出版日期2018-2