Partial Saturated Vapor Pressure of Sodium Nitrite Over the System NaNO2-KNO3

The partial pressure of sodium nitrite in the system NaNO₂-KNO₃ was measured at 798, 823, and 848 K. The dependence of the logarithm of the NaNO₂ pressure on inverse temperature is presented. Coefficients A and B of the Clausius-Clapeyron equation and the partial molar heats of vaporization are calculated. The activity and activity coefficient of sodium nitrite are determined. The dependences of ac- tivity and activity coefficient of sodium nitrite and potassium nitrate are presented as functions of composition of the NaNO₂-KNO₃ system. The consistency of the activity coefficients is verified using the Redlich-Kister integral.     

Saturated Vapor Pressure over the Melts of the NaNO2-NaNO3 System

The partial pressures of sodium nitrite and sodium nitrate over the system NaNO₂-NaNO₃ were determined at 798, 823, and 848°C. For sodium nitrate, A and B coefficients of the Clausius-Clapeyron equation, partial molar heats of vaporization, activities, and activity coefficients were calculated as functions of composition.     

Saturated Vapor Pressure Over Melts of the Binary System NaNO2-KNO3

The partial pressures of sodium nitrite and potassium nitrate over melts of the binary system NaNO₂-KNO₃ were measured at 798, 823, and 848 K. Negative deviations of the vapor pressure from Raoult's law, which decrease with increasing temperature, are established. Coefficients A and B of the Clausius-Clapeyron equation, partial molar heats of vaporization, activity and activity coefficient are calculated as functions of composition for potassium nitrate.     

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.     

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.     

Saturated Vapor Pressure in a System Constituted by Anthranilic Acid and Hydrogen Fluoride

The saturated vapor pressure in a system constituted by anthranilic (o-aminobenzoic) acid and hydrogen fluoride was studied by the static method in the temperature range 0-90°C. The isotherms of vapor pressure as a function of solution composition were approximated using the least-squares method.     

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。     

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.     

新型调压装置在液体饱和蒸气压测定实验中的应用

引入可控进气量和具有独立操作的增、减压缓冲瓶的调压装置,使气压调节缓慢可控,能连续调节缓冲瓶内气体压力以适应不同温度点的液体饱和蒸气压;可通过控制U形液柱缓慢移动来读取气液平衡状态下饱和气压值,较好地克服了以往实验中存在的调压操作困难、易发生空气倒灌及未知蒸气饱和的问题,取得了良好的实验效果,提高了实验数据的准确性。     

Temperature Dependences of the Saturated Vapor Pressure of Lantanum Complexes Based on 2-(2-Benzoxazol-2-yl)phenolate Ligand

Russian Journal of General Chemistry - Temperature dependences of the saturated vapor pressure of lanthanum complexes based on 2-(2-benzoxazol-2-yl)phenolate ligand have been obtained using the...     

Gibbs Energy and Entropy of Mixing in the NaNO2-KNO3 System

The activity and activity coefficients of the components of the NaNO₂-KNO₃ system, determined from the experimental data on the saturated vapor pressure at 798, 823, and 848 K, are used to calculate the relative and excess partial molar Gibbs energies (G _i and G _i ^{e x c}), entropies (S _i and S _i ^{e x c}), and integral relative and excess thermodynamic functions (G, G ^{e x c}, S, and S ^{e x c}) of the system.     

The Equilibrium Partial Pressure of HgI2 over and Thermodynamic Properties of Hg3Te2I2 1)

The high temperature vaporization pattern of Hg₃Te₂I₂(s,l) shows four distinctly different regimes, similar to those of the HgTe vaporization. The most predominant species in the vapor phase in all four regimes is HgI₂(g), followed by Hg(g) and, possibly, Te₂I₂(g). The width of the “homogeneity range” of Hg₃Te₂I₂(s) was determined to be less than about 0.17 mole‐% HgI₂. Applying the second‐law method to the vaporization of HgTe‐saturated Hg₃Te₂I₂(s) at higher temperatures yields the heat and entropy of vaporization of 20.9 ± 2.3 (kcal/mole) and of 27.5 ± 2.8 (cal/mole K), respectively, with estimated total uncertainties of less than ± 5.8 (kcal/mole) and ± 7.6 (cal/mole K), at an average temperature of 722 K. With an estimated heat capacity function of Hg₃Te₂I₂(s) and estimated thermodynamic values for HgI₂‐saturated HgTe(s), the heat of formation and absolute entropy of Hg₃Te₂I₂(s) are computed to be = ?49.7 ± 1.1 (kcal/mole) and = 97.3 ± 1.4 (cal/mole K), with estimated total uncertainties of ± 8.3 (kcal/mole) and ± 14.0 (cal/mole K). The combined results of this investigation provide valuable information for the crystal growth of this material from the vapor and molten phase.     

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 .     

完全不互溶双液系的蒸气压*

对完全不互溶双液系的饱和蒸气压进行了实验研究与理论讨论,认为完全不互溶双液系的平衡蒸气压随两组分相互溶解度减小而趋于但总是小于两纯组分的饱和蒸气压之和;当完全不互溶两液相一起静置时,上层液体能有效但不能完全阻止下层液体的挥发,这种阻止作用源于缓慢溶解、扩散和挥发这些动力学过程;提出了阻止下层液体挥发的方法,即用与之完全不互溶且密度小的液体来覆盖,并且2种液体充满容器,阴凉处密闭静置保存。     

热力学模拟LiNO_3-NaNO_3-KNO_3和KCl-LiCl-CaCl_2体系的三元共晶点（英文）

热力学建模可以作为有力的工具预测熔盐混合体系的共晶点,进而获得低熔点的熔盐混合物.本文作者分别采用Kohler模型和Toop模型预测了三元体系LiNO3-NaNO3-KNO3和KCl-LiCl-CaCl2的三元共晶点,预测值与实验文献报道值吻合,这证明了模型与模型参数预测相图的可靠性.基于预测的LiNO3-NaNO3-KNO3和KCl-LiCl-CaCl2体系的完整相图,找到了空位的三元共晶点.     

Oxidation of 2-Cyanothioacrylamides with Sodium Nitrite in Acidic Medium

Russian Journal of General Chemistry - (E)-3-Aryl-2-cyanoprop-2-entioamides, prepared by Knoevenagel condensation between aromatic aldehydes and cyanothioacetamide, react with sodium nitrite in...     

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。     

Ag／SiO2催化剂上气相合成3-甲基吲哚

考察了Ag/SiO2催化剂对常压下苯胺和1,2-丙二醇气相合成3-甲基吲哚的催化活性.当Ag/SiO2在500℃焙烧4h并且反应中水蒸气与氢气摩尔比为0.750时,3-甲基吲哚的收率可达35%.X射线衍射结果表明,具有银微晶的Ag/SiO2催化剂有利于3-甲基吲哚的合成。