共查询到18条相似文献,搜索用时 62 毫秒
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由于非水溶剂的应用日趋广泛,促使物理化学工作者对于溶剂和溶液性质进行研究,同时开展了有关物理化学数据的测定和积累工作,以利于指导实践[1]。目前文献报道含水混合溶剂中的电解质活度系数较多,但非水混合溶剂中电解质活度系数报道较少。电解质浓溶液活度系数的计算方法目前应用较广的是Pitzer半经验算法[2]。Pitzer的算法中具体物系的β(0)、β(1)等系数需从实测活度系数数据拟合求得。孙仁义等通过测定汽液平衡盐效应的方法研究了盐在混合溶剂中的活度系数[3-4]。最近孙仁义等[5]提出了双液比固定条件下含盐体系汽液平衡数据热力学一… 相似文献
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三元无限稀释活度系数的实验测定 总被引:1,自引:0,他引:1
三元无限稀释活度系数的实验测定鲍坚斌,周秋红,李昂,韩世钧(浙江大学化学系,杭州,310027)关键词三元无限稀释活度系数,气提法,汽液平衡,液液平衡传统的无限稀释活度系数一般是指二元无限稀释活度系数,即(i为无限稀释单组分溶质,j为单组分溶剂),它... 相似文献
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如果溶剂是高挥发性物质,当用气提法测定无限稀释活度系数时需要加预饱和釜以消除气提时因溶剂量损失过大而带来的问题.本文就丙酮-甲基环戊烷、丙酮-环己烧和丙酮-甲基环己烷3个体系在298.2~318.2K温度范围内的γ~∞作了测定,用所得数据作全浓度范围的汽液平衡推算,与文献中实验值对比,发现Wilson方程结果最佳. 相似文献
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活度系数和活度是物理化学教学中要求掌握的基本概念,溶液活度系数的测定是物理化学实验的基本内容之一,但在一般实验指导书中仅介绍气液色谱法测无限稀活度系数.而用静态平衡釜测定二元系恒温下的总压~液相组成(P~X)数据的实验,在基础物理化学实验室中是没有条件进行 相似文献
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电动势测定的应用之一——电解质离子的平均活度系数测定,是物理化学课程的基本内容。如能在基础物理化学实验中开设此实验,将有助于学生对该法的深刻理解。文献中所介绍的装置多数是带有双液封的H-型电池结构或更为复杂的电池结构.这类电池结构不仅仪器加工困难,而且由于电池结构复杂,造成体系中溶解氧不易赶出的“死角”(如连接两电极管的“桥”中的溶液),致使电池电动势难以达到平衡值。又因要采用两条通氢管路,使操作复杂 相似文献
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GLPC法测定二元系中挥发组分有限浓度时的活度系数曾为Chueh和Ziegler、Conder和Purnell、Chch和Parcher等所探讨,但因后续工作太少,迄今未能成熟,将这一方法得到肯定,对于研究二元溶液的热力学是有意义的,经过反复比较,我们决定对Chueh和Ziegler的方法作进一步探讨。 相似文献
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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 相似文献
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等压法测定298.15K下LiCl-CaCl2-H2O体系的活度系数 总被引:1,自引:0,他引:1
The isopiestic method was used to determinate isopiestic molality and osmotic coefficients in single-salt solutions of LiCl-H2O(molality range from 0.5 to 9.0 mol· kg-1),CaCl2-H2O(molality range from 0.35 to 5.2 mol· kg-1) and multisalt solution LiCl-CaCl2-H2O(ionic strength range from 0.5 to 15.7 mol· kg-1) at 298.15K,from which Pitzer's interaction parameters of single salt ,mixed salts of the systems were obtained.The mean ionic activity coefficients of LiCl、 CaCl2 in pure and mixed solutions were reported. 相似文献
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本文采用热解吸调制器作毛细管气相色谱直接顶空进样测定二元液体混合物苯-甲苯和丙酮-氯仿的活度系数。热解吸调制器是在毛细管柱前端的一段短的加热段。调制器段外部镀以一薄层导电膜。所体样品连续不断地流经调制器和毛细管柱。 相似文献
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Activity coefficients of KCl and NaCl were determined in the quaternary system KCl-NaCl-water-ethanol, for 10 and 20% (w/w) ethanol in the solvent, from experimental electromotive force data. The molalities varied from 0.1 mol kg–1 to near saturation and measurements were taken in the temperature range 20 to 50°C. The Pitzer-Simonson equations were used to describe the nonideal behavior of both electrolytes and the corresponding activity coefficients were determined for each solvent and temperature. 相似文献
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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. 相似文献
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Armin C. Schneider Christoph Pasel Michael Luckas Klaus Gerhard Schmidt Jan-Dirk Herbell 《Journal of solution chemistry》2004,33(3):257-273
The single ion activity coefficients of hydrogen and chloride ions in aqueous HCl solutions have been estimated at 25°C at concentrations up to 1 mol-kg–1, using potentiometric measurements with ion-selective electrodes and appropriate calibration procedures. Two methods are described for an internal calibration of the electrodes in the extended Debye–Hückel concentration range. The results are compared to the conventional pH calibration with external buffer solutions. Since the latter calibration method does not account for the liquid junction potential E
J which arises at the reference electrode, the resulting activity coefficients are quite different in HCl solutions of higher concentration. These differences between internal and external calibration decrease significantly, when a correction for E
J is introduced into the conventional pH calibration. Hence, in solutions of higher ionic strength the accuracy of the conventional pH electrode calibration using buffer solutions is very limited, when exact H+ activities are required. The consistency of the results indicates that the liquid junction potentials in the examined systems calculated by the Henderson/Bates approximation are of reasonable precision. 相似文献
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The activity coefficients of phenol in a number of hydrocarbons were determined from experimental data on phenol distribution between aqueous and hydrocarbon liquid phases, using data on the limiting activity coefficients of phenol in water. Ten systems containing saturated and aromatic hydrocarbons were examined in the temperature range 283–328 K.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 2, 2005, pp. 214–218.Original Russian Text Copyright © 2005 by I. Dobryakova, Yu. Dobryakov. 相似文献