Chemical speciation of aqueous hydrogen fluoride at various temperatures from 298.15 K to 353.15 K
Chemical speciation of aqueous hydrogen fluoride at various temperatures from 298.15 K to 353.15 K
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DOI：
10.1016/j.fluid.2019.112244
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发表时间：
2019-11-01
影响因子：
2.6
通讯作者：
Khamar, Lhachmi
中科院分区：
文献类型：
--
作者：
EL Guendouzi, Mohamed;Faridi, Jamal;Khamar, Lhachmi
研究了不同温度下氢氟酸水溶液的化学形态。对HF-H_2 O体系进行了定性和定量形态分析的实验和计算。综述了氟化氢水溶液的热力学和形态研究的文献，指出了在不同温度下存在的不足。HF在水溶液中的解离不完全，表现出浓度依赖的化学计量系数，直接影响热力学性质。忽略这种浓度依赖性会导致弱电解质溶液的错误渗透系数。用湿度计法测定了HF-H_2 O体系在298.15 ~ 353.15 K温度范围内，在0.10 ~ 6.00 mol·kg ~（-1）摩尔浓度范围内的水活度。在此基础上，根据氟F-19核磁共振谱和化学平衡，分别对氢氟酸水溶液进行了定性和定量形态分析。基于离子相互作用模型，建立了HF水溶液行为的预测方法，考虑了HF -H-F-HF 2-H2 F3- H2O三元体系。在不同温度下测定了计算物种HF（aq）、H+、F-、HF 2-和H2 F3。从互补技术和开发的模型，结果反映了目前的物种，并允许描述氢氟酸水溶液的行为。(C)2019爱思唯尔B. V.保留所有权利。
The chemical speciation of aqueous hydrofluoric acid solutions was investigated at various temperatures. The experimental results and calculations were carried out to study a qualitative and quantitative speciation of the system HF-H2O. Literature review of thermodynamic and speciation studies of aqueous hydrogen fluoride were reported and revealed some deficiencies at various temperatures. The dissociation of HF in the aqueous solution is not complete, which exhibits a concentration-dependent stoichiometric coefficient and directly influences the thermodynamic properties. Neglecting this concentration dependence leads to erroneous osmotic coefficients for solutions of weak electrolytes. The water activities of the HF-H2O system were measured within the molality range from 0.10 mol kg(-1) to 6.00 mol kg(-1) at different temperatures from 298.15 K to 353.15 K using the hygrometric method. From these measurements, on the basis of the fluorine F-19 nuclear magnetic resonance and the chemical equilibriums, the qualitative and quantitative speciation aqueous hydrofluoric acid solutions were performed respectively. The deployed approach was developed based on ion interaction model to describe the behavior of HF aqueous solutions, considering a polyelectrolyte system HF - H - F - HF2- H2F3- H2O. The calculated species HF(aq), H+, F-, HF2- and H2F3 were determined at various temperatures. From the complementary techniques and the developed model, the results reflect the present species and allow describing the behavior of hydrofluoric acid aqueous solutions. (C) 2019 Elsevier B.V. All rights reserved.