共查询到20条相似文献,搜索用时 15 毫秒
1.
在288.15~318.15K范围内,用等压法测定了四苯硼钠在不同浓度水溶液中的平均活度系数和渗透系数,计算了不同浓度时的超额自由能、相对偏摩尔焓、偏摩尔热容。经计算机曲线拟合给出热力学性质的经验计算公式。 相似文献
2.
Kamalendra N. Das M. Habibullah K. S. Uddin P. Barua 《Journal of solution chemistry》2006,35(7):1017-1028
The Grunberg-Nissan type interaction parameters have been used to treat volumetric and viscometric excess function data. Calculations have been made easier by using the reduced excess functions. The composition and temperature dependencies of the interaction parameters were found to depend on the nature of the dominant constituent. Using the Eyring theory of viscosity and the ERAS model, the reduced excess viscosity was equated with the Gibbs energy of mixing. A two-term Guggenheim Polynomial was used to explain the composition dependence of the excess functions. 相似文献
3.
咪唑啉型表面活性剂组成微乳液的热力学性质 总被引:3,自引:0,他引:3
由咪唑啉型表面活性剂、醇、水和正十六烷组成微乳液,探讨了该微乳液中醇从油相转移到界面相时的自由能变化及温度对自由能变化的影响,算得了熵变和焓变。 相似文献
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信息拓扑指数与烷烃分子热力学性质的关系 总被引:13,自引:0,他引:13
Two topological information indices were constructed based on Randic and Wiener indices, and the values of topological information indices for 85 alkanes were calculated. The thermodynamic properties such as the standard enthalpies of formation, the standard entropies and the standard free energies of formation for these alkanes were also correlated with these topological and information indices. It is found that the thermodynamic properties calculated for both gaseous and liquid states of the 85 alkanes are in excellent agreement with the experimental values through the regression analysis. 相似文献
6.
Densities and apparent molar volumes of aqueous 2-chloroethanol were determined at temperatures from 15.0 to 34.4°C using digital densimetry. The results of the volumetric measurements have been used to calculate the following thermodynamic quantites at 25°C: V
2
o = 55.05 ± 0.02 cm3-mol–1, (V
2
o/T)p = 0.01486 ± 0.00318 cm3-K–1-mol–1, and (2
V
2
o/T
2)p = 0.02972 ± 0.00318 cm3-K–2-mol–1. Partial molar volumes of transfer from water to 1 mol-dm–3 2-chloroethanol have also been determined for L-glycine, L-alanine, L-serine, L-glutamic acid, and L-aspartic acid at 35.0°C. The transfer results have been explained in terms of the nature of the interactions of the groups in the solute and solvent. Hydration numbers of L-glycine and L-alanine have also been calculated in aqueous 2-chloroethanol. 相似文献
7.
稀土气态配合物的热力学性质 总被引:1,自引:0,他引:1
稀土气态配合物的热力学性质王林山,王之昌(东北大学化学系,沈阳,110006)关键词稀土气态配合物,热力学性质,钆断目前,对稀土液相和固相配合物已有了较为全面的研究,并总结出其热力学性质与原子序数或离子基态之间有钆断、四分组、斜W等实验规律或效应[1... 相似文献
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在乙醇和水混合溶剂中恒定乙醇质量分数x=0.2,应用经典的电动势方法测定无液体接界电池的电动势:
Pt,H2(1.013×105 Pa)│HCl(0.01 m),乙醇(x),H2O(1-x)│AgCl-Ag(A)
Pt,H2(1.013×105 Pa)│GHCl(m1),G±(m2),乙醇(x),H2O(1-x)│AgCl Ag(B)
其中GHCl代表甘氨酸的盐酸盐,根据电池(A)和(B)的电动势,用传统的 Debye Hückel外推方法和该文提出的多项式逼近法,确定了甘氨酸在278.15~318.15 K范围内5个温度下的一级热力学解离常数,两种方法得出的结果在实验误差范围内一致.计算了甘氨酸一级解离过程的其它热力学参数. 相似文献
10.
采用平面波赝势密度泛函理论,利用第一性原理的方法研究了EuS的晶体结构、高压相变以及弹性性质.计算结果和实验值以及前人利用不同计算模型得到的理论值相吻合.研究了EuS的弹性常数、弹性模量和弹性的各向异性等力学性质随压力变化的趋势.同时研究了泊松比、德拜温度及纵波和横波的弹性波速随压力的变化趋势.基于德拜模型,进而研究了EuS在0-800K和0-60GPa下相变前后的热膨胀系数、热熔、Gruneisen参数等热力学性质. 相似文献
11.
The results of recent developments on modelling of supramolecular ordering and physicochemical properties of molecular mixtures
have been reviewed. The main attention is paid to the unified approach based on a generalized quasichemical model for a set
of thermodynamic, dielectric and optical properties of mixtures, self-organized by specific bonding. Interrelations between
thermodynamic, as well as dielectric, and optical properties of liquid mixtures, reflecting different molecular parameters,
and the characteristics of quasichemical processes are presented. Applications for thermodynamic functions of mixing, permittivity,
coefficients Rayleigh light scattering in molecular mixtures are considered. Data on thermodynamics of aggregation in mixtures
have been obtained.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
The catalytic properties of all proteinogenic, acyclic amino acids for direct aldol reaction in H2O, assisted by various surfactants, were investigated. The basic and neutral amino acids were shown to be efficient catalysts, giving rise to good‐to‐excellent yields of adducts (up to 95%), with moderate‐to‐good diastereoselectivities (up to 86%), L ‐arginine being the most‐effective catalyst. The syn/anti diastereoisomer ratio could be readily tuned by proper choice of the amino acid used. Also, the range of substrates that underwent the reaction was extended to less‐reactive aldehydes carrying electron‐donating Br substituents. 相似文献
13.
Recently,therehasbeenagreatdealofinterestinbiosurfactants,i.e.,surthce-activecompoundsproducedbymicroorganisms'orisolatedenzymes'.BiosurthctantspossessanLlmberofpotentialadvantagesovertheirchemicallymanufacturedcounterparts,includinglowtoxicity',biodegradability,awidevarietyofpossiblestructuresandeaseofsynthesisti.olninexpensive.renewablerawmaterials.Consequently,biosurfactantsmayhaveimportantapplicationsinnumerousareas,suchasfoods,cosmetics,personal-careproducts.alldpharmaceuticalformulation… 相似文献
14.
利用表面张力法, 研究了非离子表面活性剂Triton X-100和离子表面活性剂十六烷基三甲基溴化铵(CTAB)混合体系在混合极性溶剂乙二醇/水(乙二醇的体积分数分别为5%、10%和20%)中的热力学性质和胶团化行为. 结果表明, 混合体系在乙二醇水溶液中存在协同效应, 临界胶束浓度随乙二醇含量的增加而增大. 利用Rubingh和Maeda模型计算了混合物中各组分在胶团相中的组成、相互作用参数以及自由能的贡献. 在实验研究的乙二醇浓度范围内, 发现该非离子/离子混合体系在离子组分摩尔分数约为0.3时, 协同效应最强. 相似文献
15.
A generalized thermodynamic equation is presented in this paper. 相似文献
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应用参考作用格位模型理论计算了二甲基亚砜(DMSO)摩尔分数为0.002时不同温度下溶液的微观结构和热力学性质. 计算结果表明, DMSO加入到水中能够增强溶液的分子网络结构. 温度升高, 配位数减小, 溶液中分子排布趋向无序. 平均力势的波动增大表明分子间的诱导力表现为斥力. 计算得到的各种热力学性质显示: 温度升高, 溶液的熵和溶剂化自由能增加, 相互作用能和过剩化学位也增加, 即高温下溶液越来越偏离理想溶液; 空位形成能降低表明溶液分子结构在高温下更容易重组. 相似文献
19.
Relative densities,
, and heat capacity ratios,
of aqueous L-histidine, L-phenylalanine, L-tyrosine, L-tryptophan, and L-2,3-dihydroxyphenylalanine (L-dopa) have been measured at 15, 25, 40, and 55°C and 0.1 MPa. Apparent molar volumes, V
2,, apparent molar heat capacities, CP2,, partial molar volumes at infinite dilution,
, and partial molar heat capacities at infinite dilution,
, have been calculated from these measurements and compared to available literature values. The partial molar properties at infinite dilution for these systems have been added to those previously obtained for amino acids and peptides in water and the combined set used as input to a novel additivity analysis. The model we develop is based upon the equations of state of Helgeson, Kirkham, and Flowers (HKF) and has been constructed with additive parameters. The model may be used to predict thermodynamic properties of many aqueous biochemicals over an extended temperature range. Group contributions to the parameters in our model and effective Born coefficients are reported for 24 aqueous amino acid and peptide systems. Our results are compared to data previously published in the literature. 相似文献
20.
Ultrasonic velocities and densities at five different temperatures over the entire composition range for aqueous solutions of 1,2, 1,3, 1,4, and 2,3 butanediols were measured. Excess volumes and adiabatic compressibilities were calculated using the experimental data. Apparent and partial molar volumes and compressibilities were analyzed to evaluate the departure from ideal solution behavior. From the analysis of the results, the interactions of isomeric butanediols with water are discussed in terms of the placements of hydroxyl groups in the isomeric butanediol molecules. 相似文献