苯+环己烷、苯+正庚烷和环己烷+正庚烷的蒸汽压和过量Gibbs自由焓研究

本文采用简单的装置,测定了苯+环己烷(313.25K),苯+正庚烷(308.19K)和环已烷+正庚烷(298.15K)三个体系的蒸汽压-液相组成关系,并由此求得了体系的过量Gibbs自由焓,结果良好。     

部份互溶体系4-甲基-2-戊醇和水的过量焓研究

使用LKB-2107型流动式微量量热计测定了4-甲基-2-戊醇和水这一部份互溶体系在293.15 K、298.15 K和303.15 K的常压过量焓。测量结果用Redlich-Kister方程作了关联。另外,还用该体系富醇区的过量焓数据拟合NRTL模型的参数与温度关系,推算较高温度下该体系的常压汽液平衡(VLE)组成及泡点。推算值与文献值是接近的。实验试剂4-甲基-2-戊醇由粗品经三次蒸馏提纯,沸点为404.95 K,折光率n_D~(20)1.4113,密度d~(20)0.8067 g cm~(-3),与文献值一致。无水乙醇、尿素均为分析纯。液体试剂在使用前均     

含醇二元体系热力学性质的研究 Ⅱ.C_1～C_5正链醇+1,4-二氧六圜的过量焓

本工作利用Picker混合型流动微量量热器测量了298.15K时,1,4-二氧六圜+甲醇,+乙醇,+正丙醇,+正丁醇和+正戊醇的摩尔过量焓。仪器以苯+环已烷和苯+四氯化碳两个体系校验,x=0.5时的混合热数值,与文献值相符在1％以内。试剂按常规方法处理,纯化液体的折光率,与文献值一致。将测得各体系的摩尔过量焓,拟合为如下的多项式:     

正丁醇、乙酸乙酯、正己烷的二元及三元体系的超额焓测量和关联

用等温稀释量热计测定了正己烷+正丁醇、正己烷+乙酸乙酯二元体系在303.15K、308.15K及正丁醇+乙酸乙酯+正己烷三元体系在303.15K的超额焓,用Kretschrner-Wiebe理论组合UNIQUAC方程所得数学模型对二元体系在303.15K的超颠焓进行了关联,并预测了所测三元体系在303.15K的超额焓,预测结果与实验值比较,平均偏差为6％。     

α-蒎烯+对伞花烃和β-蒎烯+对伞花烃二元体系超额焓的测定

采用BT2.15型Calvet微量量热计常压下测定了α-蒎烯+对伞花烃和β-蒎烯+对伞花烃两个二元体系在298.15 K、308.15 K及318.15 K下的超额焓. 实验数据采用Redlich-Kister方程进行关联, 标准偏差较小. 该两个二元体系的超额焓在全浓度范围内均为正值, 其最大值在摩尔分数x1=0.5附近. 温度对超额焓有一定的影响, 超额焓随温度的升高而增大. 相同温度下, α-蒎烯+对伞花烃体系的超额焓比β-蒎烯+对伞花烃体系的大.     

铁-铬-钒三元系固态合金的量热研究

本文介绍一种自制环境等温型高温量热计, 其原理基于差热分析。在1300 K下所测纯铁等相变热与文献值吻合甚好, 证明仪器可靠。应用此仪器系统测量了Fe-Cr-V三元系九种不同成份的α-合金生成焓, 以及它们的α-α相变焓。为该体系的热力学研究提供了一些必要的热化学数据。     

溶解量热法测三氧化钼标准生成焓

用溶解量热法,以KIO_4和KOH组成的弱碱性溶液为量热溶剂,设计3个不同的热化学循环,用RD-1型热导式自动量热计测定了MoO_3的标准生成焓,并推荐其值为ΔH_(t(moO_3))~0(298.15K)=-765.0±6.8kJ·mol~(-1)。     

库水硼镁石2MgO.3B2O3.15H2O的65-310K间的比热测定及其热力学性质的计算

用真空绝热量热计测定了库水硼镁石2MgO.3B2O3.15H2O在65-310K间的比热.根据Debye-Einsein函数组合式, 计算了0-65K间的比热, 其误差为0.4%.在65-310K范围内, 每隔5K, 计算了熵、焓和自由能函数.     

铁-镍-钒三元系固态合金的量热研究——双子、差示、高温量热计

本文介绍一种自制双子、差示、高温量热计,此仪器用于测量固态合金的生成焓和相变焓。最高工作温度可达1200℃。通过测定已知焓值的纯铁的相变焓,证明量热计可靠。用这台量热计测量了8种不同成份的Fe-Ni-V固态合金的生成焓,其中包含σ相和γ相。为该体系的热力学研究提供了必要的热化学数据。     

硝酸钕和钐的水合物在水中溶解热的测定

本文用补偿式数字量热计测定了六水、四水硝酸钕和六水、五水硝酸钐298.15K时在水中的溶解热,求得了它们的标准生成热、相应的标准脱水焓和晶格能。     

聚四氟乙烯等温稀释型量热计

过量焓是溶液的基本热力学性质,近廾年来不少学者对它进行了大量的研究,取得了引人注目的成绩。目前应用较多的为等温稀释型及流动型量热计。尽管后者具有速度快、试剂用量省等优点,但前者结构简单、操作方便和实验精度高,因此得到广泛的应用。传统的等温稀释型量热计的本体为玻璃杜瓦瓶,当活塞上下移动时常常引起破裂,另一方面由于使用汞封,使实验物料受到很大限制。为了克服这些缺点,我们用聚四氟乙烯作为量热计本体,取得满意的效     

Excess molar enthalpies of 1,3-dioxolane,or 1,4-dioxane with isomeric butanols

Using a flow-mixing calorimeter, excess molar enthalpies of 1,3-dioxolane, or 1,4-dioxane, with isomeric butanols were determined at the temperatures of 298.15 K and 313.15 K. All the studied systems show positive excess molar enthalpies. The results are compared with calculated values from the UNIFAC model.     

Measurement and correlation of excess molar enthalpy at various temperatures acetonitrile + diethylamine or <Emphasis Type="Italic">s</Emphasis>-butylamine mixtures

Summary As a continuation of our studies on excess functions of binary systems containing acetonitrile-amines mixtures, in this work excess molar enthalpy (H_m^E) of acetonitrile+diethylamine or s-butylamine mixtures have been determined as a function of composition at 288.15, 293.15, 298.15 and 303.15 K at atmospheric pressure using a modified 1455 Parr adiabatic calorimeter. The excess enthalpy data are positive for both systems over the whole composition range. ERAS-Model calculations allowing for self-association and cross-association of the components were performed. The results of the calculations and the influence of temperature and isomers chains on the excess enthalpy behavior are discussed.     

环己酮-醇二元系统超额焓测定和关联的研究

用MS-80型Calvet微热量计首次测定了环己酮＋乙醇、＋正丙醇、＋正丁醇、＋环戊醇、＋环己醇系统在293.15、298.15、303.15及308.15 K四个温度下的超额焓HE,并拟合为平滑方程,拟合方差很小.环己酮和醇组成的二元混合系统的超额焓在全浓度范围内都为正值,其最大值都处在醇浓度为50％附近.超额焓随着醇分子中含碳原子数的增多而增大；超额焓值受温度的影响很大,且随着温度的升高而增大.     

Molar excess enthalpies of ethyl acetate + alkanols at T = 298.15 K, p = 10.0 MPa

A commercial flow-mixing isothermal calorimeter was tested by measuring heat of mixing curves for exothermic, endothermic, S-shaped and double minimum molar excess enthalpy mixtures at high pressure. The results show this calorimeter is able to produce good quality data. Molar excess enthalpies for ethyl acetate mixed with a series of simple alkanols were measured at T = 298.15 K and p = 10 MPa.     

The excess enthalpy of (tetrachloromethane + carbon disulphide) and (tetrachloromethane + dichloromethane) over a range of temperatures and pressures

Measurements of the excess molar enthalpy of (tetrachloromethane + carbon disulphide) and (tetrachloromethane + dichloromethane) have been made using an isothermal high-pressure flow calorimeter. The measurements for (tetrachloromethane + carbon disulphide) cover the range 283.15 to 323.15 K at pressures between 0.1 and 30 MPa. The excess molar enthalpies for (tetrachloromethane + dichloromethane) are reported at 298.15 K at 0.1, 15, and 30 MPa, and at 323.15 K at 0.2 MPa. The thermodynamic consistency of the results is shown by deriving the temperature dependence of the excess molar Gibbs free energy from them and comparing with published experimental values.     

水与正丁醇二元体系最低共沸混合物的热容

Molar heat capacities of n-butanol and the azeotropic mixture in the binary system [water （x=0.716） plus n-butanol （x=0.284）] were measured with an adiabatic calorimeter in a temperature range from 78 to 320 K. The functions of the heat capacity with respect to thermodynamic temperature were estabhshed for the azeotropic mixture. A glass transition was observed at （111.9±1.2） K. The phase transitions took place at （179.26±0.77） and （269.69±0.14） K corresponding to the solid-hquid phase transitions of n-butanol and water, respectively. The phase-transition enthalpy and entropy of water were calculated. A thermodynamic function of excess molar heat capacity with respect to temperature was estabhshed, which took account of physical mixing, destructions of self-association and cross-association for n-butanol and water, respectively. The thermodynamic functions and the excess thermodynamic ones of the binary systems relative to 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity and the calculated excess heat capacity with respect to temperature.     

Excess enthalpies of ether + alcohol + hydrocarbon mixtures: Binary and ternary mixtures containing dibutyl ether (DBE), 1-butanol and benzene at 298.15 K and 313.15 K

Experimental excess molar enthalpies of the ternary systems dibutyl ether (DBE) + 1-butanol + benzene and the corresponding binary systems at T = 298.15 K and T = 313.15 K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and the ternary systems show endothermic character. The experimental data for the binary and ternary systems have been fitted using the Redlich-Kister equation and the NRTL and UNIQUAC models. The values of the standard deviation indicate good agreement between the experimental results and those calculated from the equations.