Thermodynamics of binary mixtures containing aldehydes. excess enthalpies of n-alkanals + benzene and + tetrachloromethane mixtures

Molar excess enthalpies H^E have been measured as a function of mole fraction at atmospheric pressure and 298.15 K for the binary liquid mixtures of ethanal, propanal, butanal and pentanal + benzene or + tetrachloromethane. The results show that the excess enthalpies decrease with increasing the n-alkanal chain length, with negative values for n-pentanal.     

Excess enthalpies of the ternary mixtures: tetrahydrofuran + (diisopropyl ether or 2-methyltetrahydrofuran) + n-heptane at 298.15 K

Excess molar enthalpies, measured at 298.15 K in a flow microcalorimeter, are reported for the ternary mixtures (tetrahydrofuran + diisopropyl ether + n-heptane) and (tetrahydrofuran + 2-methyltetrahydrofuran + n-heptane). Smooth representations of the results are described and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. The latter are compared with diagrams obtained when the model of Liebermann and Fried is used to estimate the excess enthalpies of the ternary mixtures from the physical properties of the components and their binary mixtures.     

The thermodynamic properties of binary mixtures containing carbon disulphide I. Phase diagrams and excess volumes

Phase diagrams and excess volumes at 298.15 K have been measured for the four binary mixtures carbon disulphide+cyclohexane, +n-hexane, +1,5-hexadiene, and +1,5-hexadiyne. The results are discussed qualitatively in the light of recent theoretical calculations of the structure and thermodynamic properties of mixtures containing anisotropic molecules.     

Excess volumes for n-alkanols + n-alkanes I. Binary mixtures of methanol,ethanol, n-propanol,and n-butanol + n-heptane

Excess volumes V^E measured at 298.15 K in a successive-dilution dilatometer are reported for binary mixtures of the n-alkanols C₁ to C₄ + n-heptane. For ethanol +, and n-butanol + n-heptane, the measurements were extended to high dilutions of alkanol. V^E is positive for all of the mixtures but decreases rapidly in magnitude for increasing chain length of the n-alkanol. The results were used to estimate the excess partial molar volumes of the components.     

Thermodynamic properties of binary mixtures containing aldehydes. II. Liquid-vapor equilibria in normal or branched alkanal + normal alkane mixtures: Analysis in terms of a quasichemical group-contribution model

Recent liquid-vapor equilibrium data for three alkanal + n-alkane mixtures are examined on the basis of the surface-interaction version of the quasichemical group-contribution theory used in Part I to correlate and predict excess enthalpies and excess Gibbs energies for such mixtures. The predictions prove to be accurate to better than 10%. Using the new data, revised interaction parameters are proposed for the estimation of liquid-vapor equilibrium for normal or branched alkanal + normal alkane mixtures.     

Thermodynamics of complex formation in ternary liquid mixtures containing acetonitrile

Vapor—liquid and liquid—liquid equilibria and excess enthalpies for ternary mixtures formed from acetonitrile, benzene, n-heptane, toluene, and carbon tetrachloride are successfully correlated with a modified version of the associated solution theory proposed by Lorimer and Jones in 1977, which assumes two types of self-association for acetonitrile and binary complexes between acetonitrile and unsaturated hydrocarbons and does not include any ternary parameters.     

Measurements of vapour-liquid equilibria,densities, viscosities and dielectric properties of cyclohexanone + triethylamine mixtures with respect to keto-enol tautomerism

Densities, ?, kinematic viscosities ν, refractive indices n_D referred to the sodium D-line, static relative permittivities ε, specific conductances κ and vapour-liquid equilibrium data for cyclohexanone + triethylamine mixtures have been determined at two temperatures. Excess properties of mixing calculated from these data indicate that in such mixtures considerable amounts of enol-amine associates are formed. The permittivity data indicate that the formation of associates is an exothermic process, which also has a marked influence on the thermodynamic excess properties of the mixtures. The enol-amine associates may undergo electrolytic dissociation. A common evaluation of static relative permittivities and specific conductances shows that for the mixture the conductance data are affected considerably by the formation of undissociated ion pairs in the sense of Bjerrum theory, especially at concentrations of the mixture where it is less polar. The conductance data are also influenced considerably by the fact that the ion pairs are solvated if the molar ratio of triethylamine exceeds 0.5.     

Cation transport at 25°c from binary Tl+Mn+ and K+Mn+ nitrate mixtures in a H2OCHCl3H2O liquid membrane system containing a series of macrocyclic polyether carriers

Carrier-mediated cation fluxes were determined using a H₂OCHC1₃H₂O liquid merebrane system for TlNO₃ and for binary mixtures of either TlNO₃ or KNO₃ with alkali metal ions, alkaline earth metal ions, and Pb²⁺ (in the case of TlNO₃). Both macrocyclic polyether and cryptand ligands were used as carriers. In Tl⁺Mⁿ⁺ mixtures, selective transport of Tl⁺ was found over all cations studied, except in the cases of Ag⁺ by 2.2 and of Pb²⁺ by 18C6, DC18C6, ClDKP18C6, and 2.2. Generally, K⁺ was transported selectively from K⁺Mⁿ⁺ mixtures, except in the cases of K⁺Tl⁺ mixtures in which Tl⁺ was transported selectively in all cases. A model relating cation flux to log K(CH₃OH) for Mⁿ⁺—macrocycle interaction and to ion-partitioning between the organic and aqueous phases was successful in rationalizing selective cation transport in most of the systems studied.     

Thermodynamics of molecular interactions in binary mixtures of non-electrolytes. Molar excess volumes

Molar excess volumes, V^E, for pyridine (A) + α-picoline (B), + β-picoline (B) and + γ-picoline (B) and benzene (A) + toluene (B), + o-xylene (B) and + p-xylene (B) and carbon tetrachloride (A) + n-heptane (B) have been measured dilatometrically as a function of temperature and composition and have been utilized to study B—B and B—B—B interactions in the presence of A via the Mayer—McMillan approach. A model has also been presented to account for these B—B and B—B—B interactions. The V^E data at 308.15 K have also been analysed in terms of the “graph theoretical” approach which describes the V^E data well for all these mixtures at 308.15 K. The “graph theoretical” approach has further been extended to successfully evaluate V^E data for a mixture at any temperature, T₂, when the V^E data at T₁ are known.     

Critical Loci for binary chloroalkane-n-alkane mixtures.I.1,2-dichloroethane with C3-C9n-alkanes

Gas—liquid critical temperature and pressure were determined experimentally at several compositions for the seven mixtures formed by 1,2-dichloroethane with propane through to n-nonane. The results are presented on the p - T, T - x and p - x planes which reveal a regular pattern of behaviour as the size of the n-alkane varies.     

On the thermodynamics of alcohol solutions. Phase equilibria of binary and ternary mixtures containing any number of alcohols

Nagata, I., 1985. On the thermodynamics of alcohol solutions. Phase equilibria of binary and ternary mixtures containing any number of alcohols. Fluid Phase Equilibria, 19: 153–174.Binary vapor—liquid and liquid—liquid equilibrium data for alcohol solutions includin one or two alcohols are correlated with the UNIQUAC associated solution theory (Nagata and Kawamura). The theory uses pure liquid association constants determined by the method of Brandani and a single value of the enthalpy of the hydrogen bond equal to ?23.2 kJ mol ^?1 for pure alcohols. For alcohol-active nonassociating component mixtures and alcohol—alcohol mixtures the theory involves additional solvation constants. The theory is extended to contain ternary mixtures with any number of alcohols. Ternary predictions of vapor—liquid and liquid—liquid equilibria are performed using only binary parameters. Good agreement is obtained between calculated and experimental results for many representative mixtures.     

Thermodynamic properties of 3-pentanol + diethylamine mixtures

Values for excess functions (H^E,V^E,G^E, TS^E) are reported for 3-pentanol+ diethylamine mixtures at 298.15 K. The results indicate formation of three hydrogen bonds per molecule 3-pentanol in excess diethylamine, and of two hydrogen bonds per molecule diethylamine in excess 3-pentanol.     

Solid + liquid phase diagrams,NMR and colorimetric measurements of mixtures

Solid+liquid equilibrium, NMR and colorimetric measurements have been made for the mixtures of o-phenylenediamine+phenol, p-phenylenediamine+hydroquinone, m-phenylenediamine+phenol, m-phenylenediamine+hydroquinone, p-phenylenediamine+phenol, and p-phenylenediamine+hydroquinone. The types and melting temperatures of the complexes formed in these mixtures were ascertained from phase diagrams. The nature of the complexes was ascertained from colorimetric and NMR data.     

p, T, x, y data of benzene + n-hexane and cyclohexane + n-heptane systems

The isothermal vapour—liquid equilibria of the benzene + n-hexane and cyclohexane + n-heptane systems have been studied using a dynamic method. The thermodynamic consistency of the data has been tested and the prediction from several empirical and semitheoretical models have been compared with the experimental values of different excess properties.     

Application of the principle of congruence to ternary alkane mixtures

Excess enthalpies and excess volumes at 298.15 K and atmospheric pressure have been measured for mixtures of n-hexane + (an equimolar mixture of n-tridecane + n-nonadecane). The agreement of the results with the corresponding results for mixtures of n-hexane + n-hexadecane is interpreted as confirmation of the applicability of the principle of congruence to multicomponent mixtures.     

Vapor–liquid critical properties of multi-component mixtures containing carbon dioxide and n-alkanes

Vapor–liquid critical temperatures, pressures and densities of multi-component mixtures containing CO₂ and n-alkanes (C4–C7) were measured in a high-pressure view cell by direct visual observations. The molar ratio of alkanes was fixed during the experiment while the composition of CO₂ was varied over the whole range. The critical loci show type I fluid phase behavior if the n-alkanes mixture is treated as a pseudo-continuous component, while correspondingly, CO₂ is a discrete component. The critical properties were calculated by Redlich–Kwong–Soave equation of state (SRK) combined with a renormalization group correction (RG). The predictions of critical properties by SRK + RG are in good agreement with the experimental results.