非等温等蒸气压法及其在Pt-Zn相关系研究中的应用

非等温等蒸气压法具有集样品制备、活度测定和相关系研究为一体的特点,本文简要阐述了非等温等蒸气压法的实验原理,分析了活度实验测定的误差以及非等温等蒸气压法在合金热力学和相关系研究中的应用,并讨论了相图十分不完善的Pt-Zn二元系的相关系.     

萃取体系的热力学研究(Ⅰ)——磷-32标记TBP分配法测定TBP-惰性溶剂二元体系的活度系数

本文提出用磷-32标记TBP分配法,测定TBP-惰性溶剂(苯、正己烷、四氮化碳、三氯甲烷等)二元体系的活度系数。此法比常用的蒸气压法、溶解度法等操作简便、快速准确和测量浓度范围大、应用体系广。实验测得四种不同溶剂体系中各种浓度TBP的活度系数,并根据实验的结果对溶剂的影响进行了讨论。     

一些苯磺酸钠盐的等压渗透系数和活度系数

用等压法测量了苯亚磺酸钠、苯磺酸钠、对羟基苯磺酸钠、间硝基苯磺酸钠和对氨基苯磺酸钠水溶液在298.15K时的渗透系数和活度系数。由此计算了它们的超额吉布斯自由能。对活度系数随浓度的变化规律进行了讨论     

5,10,15,20-四(对-磺酸苯基)卟啉四钠盐水溶液的稀释热和活度系数的研究

使用LKB 2107微热量计系统和等压法测量仪,分别测量了25℃时5,10,15,20-四(对-磺酸苯基)卟啉四钠盐水溶液的稀释热和活度系数,计算了相对偏摩焓。     

含锂水盐体系热力学性质研究:LiCl-MgCl~2-H~O体系渗透系数和活度系数的等压测定

25℃下,用等压法测定了单盐水溶液(浓度范围分别为0.5-19.8mol.kg^-1,0.3-6.0mol.kg^-1)以及混合水溶液(离子强度范围为0.6-19.4mol.kg^-1)的水活度和渗透系数,同时测定了LiCl的溶解度.该体系的实验等水活度线符合本工作推导出的Zdanovskii规则扩展式,用Gibbs-Duhem方程和改进的Mckay-perring方法计算了单盐和混合盐水溶液的活度系数.由本实验获得的渗透系数拟合了Pitzer单盐和混合作用参数,检验了Pitzer方程对该体系渗透系数、活度系数和溶解度预测的适用性.用Pitzer方程取本工作得到的参数计算的溶解度与文献实验值基本一致.     

含锂水盐体系热力学性质研究:LiCl-MgCl~2-H~O体系渗透系数和活度系数的等压测定

25℃下,用等压法测定了单盐水溶液(浓度范围分别为0.5-19.8mol.kg^-1,0.3-6.0mol.kg^-1)以及混合水溶液(离子强度范围为0.6-19.4mol.kg^-1)的水活度和渗透系数,同时测定了LiCl的溶解度.该体系的实验等水活度线符合本工作推导出的Zdanovskii规则扩展式,用Gibbs-Duhem方程和改进的Mckay-perring方法计算了单盐和混合盐水溶液的活度系数.由本实验获得的渗透系数拟合了Pitzer单盐和混合作用参数,检验了Pitzer方程对该体系渗透系数、活度系数和溶解度预测的适用性.用Pitzer方程取本工作得到的参数计算的溶解度与文献实验值基本一致.     

含锂水盐体系热力学性质研究——LiCl-MgCl_2-H_2O体系渗透系数和活度系数的等压测定

25℃下,用等压法测定了单盐水溶液(浓度范围分别为0.5—19.8mol·kg~(-1),0.3—6.0mol·kg~(-1))以及混合水溶液(离子强度范围为0.6—19.4mol·kg~(-1))的水活度和渗透系数,同时测定了LiCl的溶解度.该体系的实验等水活度线符合本工作推导出的Zdanovskii规则扩展式.用(Gibbs-Duhem方程和改进的Mckay-Perring方法计算了单盐和混合盐水溶液的潘度系数.由本实验获得的渗透系数拟合了Pitzer单盐和混合作用参数,检验了Pitzer方程对该体系渗透系数、活度系数和溶解度预测的适用性,用Pitzer方程取本工作得到的参数计算的溶解度与文献实验值基本一致.     

气液色谱法研究溶质在溶剂中有限浓度活度系数

气液色谱法测量溶质在溶剂中有限浓度活度系数最早为Chueh和Ziegler,Conder和Purnell所探讨,Conder和Purnell提出了一系列有限浓度的普遍化保留理论和实验方法,但是他们所采用的实验设备和数据处理方法都比较复杂。Chueh和Ziegler提出了台阶冲洗法测量有限浓度活度系数的方法,得     

拟静态沸点计法测定非水电解质溶液的渗透系数

本文将非分析循环沸点计［1，2］和拟静态方法[3]应用于非水电解质溶液体系的渗透系数的测定，建立了一套拟静态沸点计法测定非水电解质溶液渗透系数的实验装置．经NaCl、NaBr两个甲醇盐溶液体系的检验，相对标准误差小于1％，与传统的苦态法和等压法比较，拟静态沸点计法是一种快速、准确、方便的方法．用该装置分别测定了29巳15K时，＊d、Me。＊Q和BU4＊Br甲酸盐溶液渗透系数，实验值用Pitier方程关联，用关联得到的Pitier相互作用参数计算了盐的活度系数．1实验部分1．1实验原理在等温的条件下，电解质溶液处于汽液平衡时，如果测出…     

钨酸钠水溶液的活度系数和渗透系数

在周期表第ⅥB族元素Cr、Mo、W六价含氧离子钠盐化合物中,钨酸盐及其在水溶液中的热力学性质是知道得最少的.钨酸钠在水溶液中的活度系数和渗透系数虽然有报道,但由于测量方法不同,给出的结果彼此相差较大.结合着无机盐水溶液热力学性质的研究,我们对钨酸钠在水溶液中的活度系数用等压法进行了测量,浓度范围从0.3到2.5mol·kg~(-1).     

Aqueous guanidinium salts: Part II. Isopiestic osmotic coefficients of guanidinium sulphate and viscosity and surface tension of guanidinium chloride, bromide, acetate, perchlorate and sulphate solutions at 298.15 K

The molality dependence of isopiestic osmotic coefficients of aqueous guanidinium sulphate, Gn₂SO₄ has been reported at 298.15 and analysed by the Pitzer equations. The Pitzer coefficients obtained from the analysis of osmotic coefficients are employed to calculate the activity coefficients. The viscosity and surface tension of aqueous guanidinium chloride (GnCl), bromide (GnBr), acetate (CH₃COOGn), perchlorate (GnClO₄) and sulphate (Gn₂SO₄) have also been measured at 298.15 K. The order in which these salts increase the viscosity and surface tension of water is: Gn₂SO₄>CH₃COOGn>GnCl>GnBr>GnClO₄. The effect of Gn₂SO₄ and CH₃COOGn on the viscosity and surface tension is stronger than that of other guanidinium salts.     

钨酸钠水溶液的活度系数和渗透系数

The activity coefficients and osmotic coefficients of Na_2WO_4 aqueous solution in the concentration range of 0.3--2.5 mol·kg~(-1) have been determined by the isopiestic method. The excess Gibbs free energies are evaluated with the correspording activity coefficientc and osmotic coefficients.     

萘二磺酸钠盐的等压渗透系数和活度系数

芳基磺酸及其盐是化学工业、染料、清洁剂和离子交换树脂等许多方面使用得非常广泛的化学材料之一。在有机化合物分子上引进磺酸基团可大大改善化合物在溶剂中的可溶性等性质.磺酸基在化学和物理现象上所引起的作用已有许多工作者进行过研究。文献[1.2.3]报导了一些苯磺酸及其盐水溶液渗透系数和活度系数的测量结果.为了比     

Thermodynamics of electrolytes. X. Enthalpy and the effect of temperature on the activity coefficients

Heat of dilution and of solution data are fitted to the form of equation corresponding to that used successfully for activity and osmotic coefficients over a wide range of concentrations. The resulting parameters give the change with temperature of the activity and osmotic coefficients. Results are reported for 84 electrolytes of 1-1, 2-1, 3-1, and 2-2 valence types.     

Vapor pressures and osmotic coefficients of the acetone solutions of three bis(tetraalkylammonium)tetrathiomolybdates at 298.15 K measured by head-space gas chromatography

The vapor pressures and osmotic coefficients of solutions of (R₄N)₂[MoS₄] (R = ethyl, n-propyl and n-butyl) in acetone have been measured by head space-gas chromatography (HS-GC). Experimental data for the osmotic coefficients have been expressed by three thermodynamic models including the ionic interaction model of Pitzer, the electrolyte non-random two liquid (e-NRTL) model and the non-random factor (NRF) model. The ability of the models to fit the osmotic coefficient was compared on the basis of the standard deviation of the fittings. The results show that the considered models provide reliable results, but the Pitzer's model gives better results than the NRTL and the NRF methods, especially in the dilute region.     

Thermodynamic studies of binary methanol and ethanol solutions of 1-dodecanol and 1-tetradecanol at 25°C

The osmotic coefficients of binary methanol and ethanol solutions of 1-dodecanol and 1-tetradecanol wer measured at 25°C up to 8 mol-kg^–1 in methanol and 5.5 mol-kg^–1 in ethanol. The activity coefficients of the solute were calculated from Bjerrum's relation. From the osmotic and activity coeficients the excess Gibbs energies of solution as well as the respective partial molar functions of solute and solvent and the virial pair interaction coefficients for the excess Gibbs energies were calculated. In addition, the difference in the Gibbs energy of solvation for the solvent in solution relative to the pure solvent was calculated, as well as the partial molar volumes and excess partial molar volumes of solutes at infinite dilution, and the coefficients of pairwise contributions to the excess volume were determined. The thermodynamic parameters obtained are discussed on the basis of solute-solvent and solute-solute interactions.     

Representation of activity coefficients of fundamental biochemicals in water by the UNIFAC model

The assignment of UNIFAC parameters has been newly examined to represent the activity coefficients of fundamental biochemicals in aqueous solutions containing sugars, imino acids, urea, amino acid salts, inorganic salts, and sugar salts.

In this work, several new groups have been introduced to represent the activity coefficients for many biochemicals with better accuracy. For sugars, a portion containing asymmetric carbon atoms in an aldohexose molecule was defined as a new group for many stereoisomers. In the case of electrolytes like amino acid salts, the Pitzer-Debye-Hückel term was added to the UNIFAC equation to take the long-range electrostatic interaction into account.

All new interaction parameters for the fundamental biochemicals have been determined from osmotic coefficient as well as activity coefficient data reported in the literature. The new parameters provided good calculated results for these biochemicals.

In addition, the activity coefficient data for the ternary systems water/amino acid/urea and water/amino acid/sucrose were used to determine the interaction parameters between the constituent groups of an amino acid and those of the second solute, urea or sucrose. The correlated results for the system containing urea were in satisfactory agreement with the literature data.     

Thermodynamic behaviour of binary mixture of 1,3-dimethoxyimidazolium bis(trifluoromethyl-sulfonyl)imide and water

The osmotic coefficient value of binary aqueous solution containing ionic liquid was obtained by using vapour-pressure osmometry technique. The change in activity and vapour pressure depression of solvent on addition of 1,3-dimethoxyimidazolium bis(trifluoromethylsulfonyl) imide ((OMe)₂Im:NTf₂) to water have been estimated at two different temperatures (T =313 K and 323 K). The experimental osmotic coefficient values of (OMe)₂Im:NTf₂ at different molality were correlated by extended Pitzer model of Archer and the ion interaction parameters were evaluated. The correlation coefficients obtained from this model were used to estimate the mean molal activity coefficient, and excess Gibbs free energy of this mixture. The osmotic coefficient values were decreased with increase in molality of the ionic liquid within the solution. The osmotic coefficient values were found to be increased with increase in temperature of the system.     

Thermodynamic properties of the system NH4NO3 + (NH4)2SO4 + H2O at 298.15 K

In this investigation, the mixed aqueous electrolyte system of nitrate and sulfate with common ammonium cation has been studied with the hygrometric method at the temperature 298.15 K. The water activities of the system [yNH₄NO₃ + (1 − y)(NH₄)₂SO₄](aq) are measured at total molalities from 0.4 mol kg⁻¹ up to saturation for different ionic-strength fractions y of NH₄NO₃ with y = 0.2, 0.5 and 0.8. The obtained data allow the deduction of osmotic coefficients. The experimental results are compared with the predictions of the Zdanovskii–Stokes–Robinson (ZSR), Leitzke and Stoughton (LSII), Kusik and Meissner (KM), and Pitzer models. From these measurements, new Pitzer mixing ionic parameters are determined and used to predict the solute activity coefficients in the mixture. The obtained results are used to calculate the excess Gibbs energy at total molalities for different ionic-strength fractions y.