纯液体饱和蒸气压测定实验中新型平衡管的应用

通过设计新型结构的平衡管,解决了液体饱和蒸气压的测定实验中存在的平衡管加样及清洗困难、气体倒灌、蒸气不纯等问题,一次加样就可完成饱和蒸气压测定工作,操作便利,效率提高,所得实验数据准确性好。     

液体饱和蒸气压测定实验的改进

从测定介质、实验方法、条件、手段及实验数据采集等方面对纯液体饱和蒸气压测定实验加以改进 ,使这一实验转变为绿色实验 ,实验水平得到提高     

“液体饱和蒸气压测定”实验新装置

“液体饱和蒸气压测定”实验新装置李慎新（自贡师范高等专科学校６４３０００）国内许多物理化学实验教材中，“液体饱和蒸气压测定”实验均采用类似图１所示的装置。这种装置主要存在下列缺点：①等压计拐弯多且一端封闭，操作不便、费时，且易损坏。②实验过程中，当调...     

饱和蒸气压测定实验中气流量调控装置的改进

In the static method of saturated vapor pressure measurements, the key operation is to adjust the pressure of the system. Because of the invisibility of the gas, it is difficult to control the air flow, which often results in air pouring into the system due to excessive air flow in the constant pressure adjustment process. By designing a mini gas flow control device, the control operation is visualized; thus, problems associated with controlling the air flow can be avoided. Furthermore, frequent adjustment of the air flow becomes unnecessary, greatly reducing the lab hour.     

参比注射法测定液体的饱和蒸气压

参比注射法测定液体的饱和蒸气压赵国华，张舟，赵国菁，李光明（同济大学化学系，上海２０００９２）物理化学实验教学中，传统测定液体饱和蒸气压的方法主要有静态法、动态法和气体饱和法等三种￣［１，２］。由于这些方法大多采用了真空系统，整套实验装置体积较大，操...     

液体饱和蒸气压测定实验仪器的改进

利用U型水银压力计做“电接点定压计” ,集多组缓冲瓶于一身 ,实现了集成供压自动化。实验证明该集成化仪器方便、易用 ,在基础实验中具有应用的实际意义     

“纯液体饱和蒸气压测定”实验装置的改进

本文对“纯液体饱和蒸气压测定”实验装置进行了系列改进，较好地处理了以往实验中的难点，提高实验的成功率，使１ｎＰ￣１／Ｔ直线的相关系数由０．９６上升到０．９９９９。     

纯液体饱和蒸气压测定实验的改进

对纯液体饱和蒸气压测定实验进行了装置创新设计,该装置解决了该实验的一些关键问题:保证相平衡时的气相为纯液体蒸气;准确测定相平衡时的温度;方便有效地调节外压与液体蒸气压相等。改进后的装置设计合理,操作简单、快捷,消除了安全隐患,大大缩短了实验时间,可一人单独操作。     

水的饱和蒸气压测定新方法——绿色化教学改革研究

通过对液体饱和蒸气压实验装置的改进和实验方案的选择,确定了一种可用于测定水的饱和蒸气压的新方法。改进后的实验不仅减少了环境污染,降低了实验成本,而且操作方便。用经过改进以后的实验方法测定温度范围为50～75℃的水的平均摩尔气化热,数量级与文献值一致,相对误差小于3%。     

微流量调节阀在液体饱和蒸气压测定实验中的应用

在液体饱和蒸气压测定实验装置中,引入微流量调节阀对缓冲储气罐进行改造,使导入系统的空气流量精确可控,解决了调压时需反复调节、操控难、空气倒灌等问题,缩短了实验时间。使用该装置以静态法测定了乙醇的饱和蒸气压,在实验教学中获得了良好的效果。     

由成核率数据拟合饱和蒸汽压力

Saturated vapor pressure was calculated from the nucleation experimental data using the thermodynamically consistent nucleation theory in which the effect of real gas is considered. The cubic polynomial fit equations of saturation pressure for several substances were obtained based on the calculation. The results of the calculations were compared to those of thermodynamic equilibrium equation and the empirical equation and applied to the predictions of the classical nucleation theory. The results show that the saturation pressures estimated from the nucleation data agree fairly well with those of empirical equations for the substances investigated, and this indicates that the predictions from the classical nucleation theory are close to the experimental data.     

静态法和动态法测量乙醇饱和蒸气压的比较

物质的蒸气压是化学、化工、冶金、医药等领域的重要基础数据。测量饱和蒸气压是大学物理化学实验教学中的一个基础实验,测量方法主要有静态法和动态法,但两种方法的比较尚未见报道。本文通过比较,得出了两种方法的优缺点以及注意事项。     

Saturated Vapor Pressure of Iridium(III) Acetylacetonate

The temperature dependency of the saturated vapor pressure of Ir(acac)₃ has been measured by the method of calibrated volume (MCV), the Knudsen method, the flow transpiration method, and the membrane method. The thermodynamic parameters of phase transition of a crystal to gas were calculated using each of these methods, and the following values of ΔH _T ⁰ (kJ mol⁻¹) and ΔS _T ⁰ (J mol⁻¹K⁻¹), respectively, were obtained: MCV: 101.59, 156.70; Knudsen: 130.54, 224.40; Flow transpiration: 129.34, 212.23; Membrane: 95.45, 149.44 Coprocessing of obtaining data (MCV, flow transportation method and Knudsen method) at temperature ranges 110−200°C as also conducted:ΔH _T ⁰ =127.9±2.1 (kJ mol⁻¹ ); ΔS _T ⁰ =215.2±5.0 (J mol⁻¹ K⁻¹ ). This revised version was published online in August 2006 with corrections to the Cover Date.     

The Use of Isothermal Heat-Conduction Calorimetry in Direct Measurements of Solvent Vapor Pressure

Principles for applying isothermal heat-conduction calorimetry for direct studies of vapor/liquid equilibria are presented. The ideas have been tested by measurements of the vapor pressure of water over aqueous NaCl(aq) solutions at 25°C. Seven different stock solutions were used with a composition ranging from 0.0879 mol-kg^–1 to saturated solution. The imprecision and inaccuracy were not dependent on the composition and were found to be about ±2 Pa over the entire composition range. The sample solution was placed in a container separated from the pure solvent which was kept in the calorimetric cell. Solvent vapor was transported isothermally between the container and the cell by means of an inert carrier gas. The vapor pressure was evaluated by measuring the heat-flow rate associated with the process where the vapor equilibrated with a NaCl(aq) solution is fully saturated by passing through pure solvent. Corrections for treating vapor phase imperfections are presented. The method was found to be fast, accurate, and easy to use. The concept developed here can easily be applied in any commercial heat-conduction calorimeter of modular design.     

建构主义理论应用于普通化学的教学实践*——以“蒸气压下降”的教学为例

在“蒸气压下降”的教学中以建构主义理论为指导,采用先具象后抽象的知识呈现方式、结合现实情境扩大知识的应用、纵向联系新旧知识的教学设计,巩固了学科知识,激发了学习兴趣,培养了学生分析问题和灵活运用理论知识解决实际问题的能力。     

Saturated Vapor Pressure and Crystal Structure of Bis-(2-imino-4-pentanonato)copper(II)

A comprehensive study of copper(II) bis-ketoiminate including tensimetric analysis of sublimation and structure solution has been carried out. The temperature dependence of saturated vapor pressure over Cu(ki)₂ crystals derived by the flow method is expressed by the equation lnP_(atm)} = 25.31-13750/T, H _subl = -114.2 ± 1.3 kJ· mole^-1, S_subl =210.2 ± 3.0> J· mole^-1 · K^-1. Crystal data for CuO₂N₂C₁₀H₁₆: a=15.143(3), b=16.681(8), c=13.795(32) , space group Ccca, Z=12, d _calc = 1.47 g/cm³, R=0.029. The structure is molecular and consists of crystallographically independent Cu(ki)₂ complexes of two types, one with a cis structure and the other with a cis–trans disordering. The copper atom has a plane square environment of two oxygen and two nitrogen atoms. In the cis isomer, Cu–O 1.938 and Cu–N 1.895 ; in the disordered complex, all four Cu–O(N) distances are 1.901 .