用电势法测定混合电解质溶液中各个组分的活度系数

本文用无液接电势电池：Ｎａ－ＩＳＥ（或Ｋ－ＩＳＥ）｜（ＮａＣｌ（ｍＡ），ＫＣｌ（ｍＢ），Ｈ２Ｏ｜Ｃｌ－ＩＳＥ同时测定了２９８．１５Ｋ，溶液离子强度Ｉ：０．１、０．５、１．０、１．５、２．０和２．５ｍｏｌ／ｋｇ时，钠电极与氯电极组成的电池和钾电极与氯电极组成的电池的可逆电势值，根据Ｎｅｒｎｓｔ方程分别求出ＮａＣｌ－ＫＣｌ－Ｈ２Ｏ体系中，ＮａＣｌ和ＫＣｌ的平均活度系数。用Ｐｉｔｚｅｒ方程拟合两套实验数据，求出两套基本一致的Ｐｉｔｚｅｒ混合参数θＮａ－Ｋ和。将混合参数代回Ｐｉｔｚｅｒ方程，分别求出另一组分的平均活度系数，计算值与实验值比较，标准偏差分别为：０．００８１（ＮａＣｌ）和０．００７３（ＫＣｌ）。     

混合电解质体系反渗透膜性能的预测

建立了一种混合电解质体系膜性能的预测方法。依据这种方法，只需一套膜规格化数据，即纯水渗透常数Ａ，氯化钠的渗透参数ＤＡＭ／Ｋδ和传质系数Ｋ，就可预测膜对任意混合电解质体系的分离性能，选用了６种醋酸纤维膜对４种混合体系（ＮａＣｌ－ＣａＣｌ２－Ｈ２Ｏ－，ＮａＣｌ－ＮａＮＯ３－Ｈ２Ｏ，ＫＩ－ＣａＣｌ２－Ｈ２Ｏ，ＮａＢｒ－ＭｇＣｌ２－Ｈ２Ｏ）的分离实验，验证了预测方法的正确性。     

HCl－NaCl－DMS－OH_2O体系中HCl的活度系数

采用电动势法测定了ＨＣｌ＋ＮａＣｌ＋ＤＭＳＯ＋Ｈ_２Ｏ体系在２９８．１５～３１８．１５Ｋ范围内，总离子强度分别恒定在Ｉ＝０．１，０．２，０．５ｍｏｌ·ｋｇ~（－１）情况下的ＨＣｌ的活度系数。应用最小二乘法拟合，表明ＨＣｌ的活度系数遵守Ｈａｒｎｅｄ规则。从粒子间微观相互作用出发阐明了Ｈａｒｎｅｄ参数α_Ａ的物理意义，并给出了α_Ａ与温度和溶液离子强度之间的关系。     

CaSO4—Na2SO4—NaCl—H2O四元体系相平衡数据的热力学关联

测定了３５℃时ＣａＳＯ４－Ｎａ２ＳＯ４－ＮａＣｌ－Ｈ２Ｏ四元体系相平衡数据，并应用Ｐｉｔｚｅｒ电解质溶液理论计算了该体系的相平衡数据，计算值与实验值吻合较好。     

离子选择性电极测定混合电解质溶液中离子活度系数

应用离子选择性电极法测定混合电解质溶液中离子活度系数,由实验结果对该方法的可行性和混合电解质水溶液活度系数随温度和浓度的变化关系进行了讨论,并对单一电解质溶液和混合电解质溶液中离子的活度系数进行了对比分析。结果表明,该方法快速、简便、灵活、成本低,是测定混合电解质溶液离子活度系数的有效方法。     

低浓度NaCl—KCl—H2O混合体系的电导

低浓度ＮａＣｌ－ＫＣｌ－Ｈ２Ｏ混合体系的电导王亭李浩然陈庚华韩世钧（浙江大学化学系，杭州３１００２７）关键词电解质溶液电导混合效应１前言Ｏｎｓａｇｅｒ－Ｆｕｏｓｓ电导理论［１～４］能够预测低浓度下多种离子共存的混合水溶液中各离子的当量电导。在１９９...     

等压法活度测定装置与溶解度预测

建立了一套玻璃材质的多歧管联球式等压法活度测定装置。测定了２９８．１５Ｋ和３２３．１５Ｋ时Ｎａ＋，Ｋ＋∥Ｃｌ－，ＮＯ－３－Ｈ２Ｏ四元体系及其二三元子体系的渗透系数，利用Ｐｉｔｚｅｒ模型预测了该１－１型四元体系的溶解度，所得结果令人满意。     

NaCl在混合溶剂(DMF-H2O)中热力学性质的研究

应用钠离子选择性电极和Ag-AgCl电极组成可逆电池,通过测定电池的电动势,应用Debye-Hückel极限公式,求得不同温度下NaCl在混合溶剂(DMF-H2O)中的活度系数(γ±),计算了NaCl在混合溶剂(DMF-H2O)中的相对偏摩尔自由能,并据电解质溶液的溶剂化理论对NaCl溶液的活度系数及相对偏摩尔自由能的变化规律进行了初步的讨论。     

电动势法确定水-丙酮-氯化钠-氯化镁体系热力学性质

采用自行设计的无液体接界电池测定了多组分电解质在水溶液和混合溶剂中不同组成时电池的电动势.利用Pitzer模型拟合实验数据,获得电池的标准电动势E(○)及电解质的活度系数.此外,计算了电解质从纯水到混合溶剂中的迁移吉布斯函数,求得了Pitzer模型的计算参数.获得了NaCl和MgCl2混合电解质的混合参数θ(NaCl)...     

混合电解质单个离子活度系数和平均活度系数的近似计算

水处理过程中所遇到的混合电解质溶液绝大多数离子强度都不高。本文简化了混合电解质溶液中单个离子活度系数和电解质平均离子活度系数的Pitzer计算式。所得简化式可方便地直接用于实际混合电解质溶液体系中活度系数的近似计算。     

NaCl在聚电解质溶液中活度系数的实验测定

引　言聚电解质是指在极性溶剂中能够电离形成聚离子和反离子的高分子[1] ,在生物体中广泛存在 ,如蛋白质、ＤＮＡ和ＲＮＡ等都是聚电解质 ,聚丙烯酸盐和聚苯乙烯磺酸盐则是典型的人工合成聚电解质 .在聚电解质的水溶液中 ,由于聚离子带有大量的电荷 ,对反离子具有很强的静电吸引作用 ,即使在极低的浓度下溶液仍具有很大的非理想性 ,这与普通电解质溶液显著不同[2 ,3 ] .建立聚电解质溶液热力学性质的计算方法一直是溶液理论研究的热点 ,现已取得长足进展 ,如Ｍａｎｎｉｎｇ的反离子凝聚理论[2 ,3 ] 、柱状胞腔模型基础上的ＰＢ方程理论[4 ,…     

电解质混合溶剂体系汽液平衡的推算

本文建立了由混合溶剂中电解质活度系数推算汽液平衡的数值计算方法。在电解质活度系数测定的盐浓度范围内,NaBr(1)-H_2O(2)-MeOH(3)和HCl(1)-H_2O(2)-MeOH(3)两体系在101.3 kPa下的汽液平衡计算结果与文献值平均绝对偏差分别为:汽相摩尔分率,平衡温度和,对前一体系还能正确地推测出交叉的盐效应规律。     

Electrical conductivities for four ternary electrolyte aqueous solutions with one or two ionic liquid components at ambient temperatures and pressure

Thiswork provides amethod to explore the transport property of the electrolyte aqueous solutionswith one or two ionic liquids, especially focus on their electrical conductivity. The conductivities were measured for the ternary systems NaCl–[C₆mim][Cl] (1-hexyl-3-methylimidazolium chloride)–H₂O, [C₆mim][BF₄]–[C₆mim][Cl]–H₂O, NaNO₃–[C₆mim][BF₄](1-hexyl-3-methylimidazolium tetrafluoroborate)–H₂O, and [C₄mim][BF₄] (1-butyl-3- methylimidazolium tetrafluoroborate)–[C₆mim][BF₄]–H₂O, and their binary subsystems NaNO₃–H₂O, NaCl–H₂O, [C₆mim][BF₄]–H₂O, [C₆mim][Cl]–H₂O, and [C₄mim][BF₄]–H₂O, respectively. The conductivities of the ternary systems were also determined using generalized Young's rule and semi-ideal solution theory in terms of the data of their binary solutions. The comparison showed that the two simple equations provide good predictions for conductivity of mixed electrolyte solutions and the mixed ionic liquid solutions based on the conductivity of their binary subsystems.     

由二元亚系的数据预测混合电解质水溶液的活度系数

The simple equation relating the activity coefficient of each solute in mixed electrolyte solution to its value in binary solutions under isopiestic equilibrium was tested by comparison with the experimental data for the 18 electrolyte solutions consisting of 1：1, 1：2, and 1：3 electrolytes. The isopiestic measurements were made on the quaternary system BaCl2-NH4Br-NaI-H2O and its ternary subsystems NaI-NH4Br-H2O, NaI-BaCl2-H2O, and NH4Br-BaCl2-H2O at 298.15K. The results were used to test the applicability of the Zdanovskii＇s rule to the mixed electrolyte solutions which contain no common ions, and the agreement is excellent. The activity coefficients of the solutes in the above quaternary and ternary systems calculated from the above-mentioned simple equation are in good agreement with the Pitzer＇s equation.     

含盐溶液汽液平衡预测

本文提出一种新的预测含盐溶液汽液平衡的方法。对Pitzer(1980年)模型进行扩展后,将其简化成单参数形式,推广至多元电解质溶液;经过适当假定,得到计算含盐挥发性强电解质和水体系及含盐水醇体系的活度系数公式,这些公式仅含有二元相互作用参数;由二元溶液的活度关联出参数后,可用于含盐体系各温度下汽液平衡的预测。关联了四十个二元电解质水溶液及七个电解质甲醇溶液298.15K时的简化Pitzer方程的单参数;用以推算六个水盐体系和二个甲醇盐体系在320-403K的蒸汽压,得到满意的结果,182个数据点的平均偏差小于0.65kPa;用以预测五个不同类型的含盐三元体系的等温、等压汽液平衡,所得的平均偏差对于汽相组成、沸点、压力分别为0.015、1K、1.92kPa。     

Comparison of activity coefficient models for electrolyte systems

Three activity coefficient models for electrolyte solutions were evaluated and compared. The activity coefficient models are: The electrolyte NRTL model (ElecNRTL) by Aspentech, the mixed solvent electrolyte model (MSE) by OLI Systems, and the Extended UNIQUAC model from the Technical University of Denmark (DTU). Test systems containing a single salt (NaCl), multiple salts, and mixed solvent aqueous electrolyte solutions were chosen. The performance of the activity coefficient models were compared regarding the accuracy of solid–liquid and vapor–liquid equilibrium calculations for the test systems. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

TERNARY NaCl+LiCl+H2O MIXED ELECTROLYTE SYSTEM: DETERMINATION OF ACTIVITY COEFFICIENTS BASED ON POTENTIOMETRIC METHOD

The mean activity coefficients for NaCl in a ternary electrolyte system were determined by the potentiometric method, at 25°C, using a solvent polymeric (PVC) sodium-selective membrane electrode (Na⁺ ISE), containing N,N′-dibenzyl-N,N′-diphenyl-1,2-phenylenedioxydiacetamide as ionophore, and combined with an Ag/AgCl electrode. The potentiometric measurements were performed at the same ionic strengths in different series of mixed salt solutions, each characterized by a fixed salt molal ratio r (where r = m₁/m₂ = 1, 10, 50, 100). The nonideal behavior of the ternary NaCl(m₁) + LiCl(m₂) + H₂O electrolyte system was described based on the Pitzer ion-interaction model for mixed salts over the ionic strength ranging from 0.01 up to about 4 mol/kg. Two- and three-particle Pitzer interaction parameters for a mixed electrolyte system were determined based on potentiometric data, and the critical role of potentiometric selectivity coefficient (K ₁₂) of ISE as limiting factor in the potentiometric measurements was analyzed.     

含盐溶液汽液平衡预测(Ⅰ)——Pitzer模型的扩展及其在多元体系中的应用

本文提出一种新的预测含盐溶液汽液平衡的方法.对Pitzer(1980)模型进行扩展后,将其简化成单参数形式,推广至多元电解质溶液;经过适当假定,得到计算含盐挥发性强电解质和水体系及含盐水醇体系的活度系数公式,这些公式仅含二元相互作用参数;由二元溶液的活度关联出该参数后,可用于含盐体系各种温度下汽液平衡的预测.关联了40个二元电解质水溶液及7个电解质甲醇溶液298.15K时的简化Pitzer方程的单参数;用以推算6个水盐体系和2个甲醇盐体系在320-403K的蒸汽压,得到满意的结果,182个数据点的平均偏差小于0.65kPa;用以预测5个不同类型的含盐三元体系的等温、等压汽液平衡,所得的平均偏差对于汽相组成、沸点、压力分别为0.015、1K和1.92kPa.