Concentrations of Individual Ionic Species in the C02-NH3-H20 System from C-13 NMR Measurements

小行星9312513 成功描述弱水电解质体系的相平衡需要准确描述液相组成。 在现在使用的模型中，计算了这种液相中所有离子物质的浓度，但这些计算的组成不是基于真实离子组成的实验测定。 为了可靠地评估现有的模型，并开发改进的模型，液相组成的实验测定将是必不可少的。 所提出的研究的目标是确定在一个典型的水性弱电解质系统中的离子物种的浓度。 具体地，建议使用碳-13 NMR来确定CO2 -NH3-H2O系统的液相中平衡的碳酸根、碳酸氢根和氨基甲酸根离子的浓度。 碳酸盐-碳酸氢盐平衡的行为已得到很好的确立。 但是，尽管CO2- NH3-H2O体系在工业和生物学上具有重要性，但涉及氨基甲酸酯的反应的平衡行为尚未在实验上建立。 建议在一定浓度和温度范围内建立这种行为。 ***

9312513 Poling The successful description of phase equilibria in aqueous-weak electrolyte systems requires an accurate description of the liquid phase composition. In models that are now used, concentrations of all the ionic species in such a liquid phase are calculated, but these calculated compositions are not based on experimental determinations of true ionic compositions. To reliably evaluate existing models, and develop improved models, experimental determinations of the liquid phase compositions will be essential. The goal of the proposed research is to determine the concentrations of the ionic species in a typical aqueous-weak electrolyte system. Specifically, it is proposed to use carbon- 13 NMR to determine the concentrations of the carbonate, bicarbonate, and carbamate ions in equilibrium in the liquid phase for the CO2 -NH3-H20 systems. The behavior of the carbonate-bicarbonate equilibrium is well established. But in spite of the industrial and biological importance of the C02- NH3-H20 system, the equilibrium behavior of reactions involving the carbamate has not been established experimentally. It is proposed to establish this behavior over a range of concentrations and temperatures. ***