Enthalpies Of Binary Mixtures Research Articles

Excess Molar Volumes and Enthalpies of Binary Mixtures Containing Furan and Toluene, 1-Octanol or n-Hexane at Temperatures Up to 383.15 K and Pressure Up to 1.6 MPa

Excess Molar Volumes and Enthalpies of Binary Mixtures Containing Furan and Toluene, 1-Octanol or n-Hexane at Temperatures Up to 383.15 K and Pressure Up to 1.6 MPa

Thermophysical properties of the binary mixtures (1,8-cineole + 1-alkanol) at T = (298.15 and 313.15) K and at atmospheric pressure

This work presents the measurements of the density, speed of sound, refractive index and enthalpy of binary mixtures containing {1,8-cineole + 1-alkanol (ethanol, 1-propanol, 1-butanol, and 1-pentanol)} at two temperatures (298.15 and 313.15) K and atmospheric pressure. The determination of excess molar volume, speed of sound deviation, refractive index deviation, molar refraction, molar refraction deviation, excess isentropic compressibility, and excess molar enthalpy are also given. Redlich–Kister equation was used to fit these derivate properties. The experimental data of the constituent binaries were analysed to discuss the nature and strengths of intermolecular interactions. Eventually some models, SAFT and PC-SAFT for density, Free Length and Collision Factor for speed of sound, Gladstone-Dale Arago-Biot for refractive index, and UNIFAC for excess molar enthalpy, among others, were successfully applied.

(Vapour+liquid) equilibria and excess molar enthalpies for binary mixtures containing N,N-dialkylamides and 1-chloroalkanes

Abstract Isothermal (vapour + liquid) equilibria (VLE) and excess molar enthalpies H m E have been measured for liquid (N,N-dimethylformamide or N,N-dimethylacetamide + 1-chlorobutane, or + 1-chlorohexane, or + 1-chlorooctane mixtures). The VLE data have been reduced using the Redlich–Kister equation taking into consideration the vapour phase imperfection in terms of 2nd molar virial coefficients. The experimental results show that both H m E and G m E are positive and increase with increasing chain length of the 1-chloroalkane.

Excess molar enthalpies of binary mixtures of trichloroethylene with six 2-alkanols at 25°C

Excess molar enthalpies HE have been measured for the binary mixtures trichloroethylene + 2-propanol, + 2-butanol, + 2-pentanol, + 2-hexanol, + 2-heptanol, and + 2-octanol using an isothermal microcalorimeter at 25°C. All the mixtures present exothermic events and showed minimum negative HE values around 0.50–0.60 mole fraction of trichloroethylene. Minimum values of HE vary from 450 J-mol−1 up to 530 J-mol−1 depending on the molecular weight of alkanol. The results are explained in terms of the strong self-association exhibited by the 2-alkanols and the formation of aggregates between unlike molecules through O···HO hydrogen bonding. The experimental results for mixtures are well represented by the Redlich–Kister, NRTL, and Wilson equations, respectively.

Excess Enthalpies of Binary Mixtures of Propanediamine+Propanediol at 298.15 K

Abstract The molar excess enthalpies of 1,2- and 1,3-propanediamine+1,2- and 1,3-propanediol have been determined at 298.15 K by using a twin-microcalorimeter which requires each component liquid 1 to 1.5 cm3 for a series of runs over the whole range of mole fraction. All excess enthalpies are exothermic and large. An equilibrium constant K1 expressed in terms of mole fractions and standard enthalpy of formation of 1:1 complex have been evaluated by ideal mixtures of momomeric molecules and their associated complexes.

Excess Enthalpies of Binary Mixtures of Formamide with Secondary Amides

The excess molar enthalpies HE of binary mixtures of formamide with N-methylformamide, N-ethylformamide, N-methylacetamide, N-ethylacetamide and N-methylpropion-amide have been measured as functions of the mole fraction at 308.15 K, using an isoperibol rotating calorimeter. The experimental values of HE are negative for all mixtures over the whole composition range. Intermolecular interactions in these mixtures are discussed through comparison of the results with those for corresponding binary mixtures of water.

Vapor−Liquid Equilibria and Excess Enthalpies for Binary Mixtures of N-Methylacetamide with 1-Octene, Dipropylamine, Triethylamine, Pyridine, and Methanol at 125 °C

Isothermal P−x data and excess enthalpies have been measured at approximately 125 °C for the binary mixtures of N-methylacetamide with 1-octene, dipropylamine, triethylamine, pyridine, and methanol...

Excess Enthalpies of Binary Mixtures of 2-Propen-1-Ol with Chloroalkanes and Chloroalkenes at 298.15 K

Abstract Excess molar enthalpies of binary mixtures of 2-propen-1-ol with 1,2-dichloroethane, 1,1,1,-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene and tetrachloroethylene have been measured at 298.15 K using a 1451 Parr model solution calorimeter. The excess enthalpy values are positive in all the systems over the entire range of mole fraction except for the system involving 1,1,2,2-tetrachloroethane. All the excess enthalpy curves are found to be S shaped. Comments on the effect of intramolecular interactions on the intermolecular interactions have been made on the basis of the experimental results.

Excess molar enthalpies of binary mixtures containing dimethylcarbonate, diethylcarbonate or propylene carbonate + three chloroalkenes at 298.15 K

Excess molar enthalpies H E m of dimethylcarbonate, diethylcarbonate or propylene carbonate + trans -1,2-dichloroethylene, + trichloroethylene, and + tetrachloroethylene, respectively have been determined at 298.15 K using an LKB flow-microcalorimeter. Experimental data have been correlated by means of the Redlich-Kister equation and adjustable parameters have been evaluated by least-squares analysis. The H E m values range from a minimum value of −1000 J mol −1 for diethylcarbonate + trans -1,2-dichloroethylene up to a maximum of 920 J mol −1 for dimethylcarbonate + tetrachloroethylene. For each series of mixtures, a systematic increase in H E m with an increase in the number of Cl atoms in the chloroalkene molecule has been noted. The results are discussed in terms of the molecular interactions.

Prediction of excess enthalpies of ketone-alkane systems from infinite dilution activity coefficients

A new approach to predicting excess enthalpies of binary mixtures from infinite dilution activity coefficients is proposed. Owing to the use of infinite dilution activity coefficients, this approach can provide the sole predicted values of excess enthalpies for a considered system at a specific temperature. It has been successfully applied to predicting the excess enthalpies of 23 ketone-alkane systems.

Excess enthalpies of binary mixtures of 2-, 3-, 4-picoline+n-alkane (C6H14-C10H22) at 298.15 K. Comparison with theory

The molar excess enthalpies measured for binary mixtures of 2-, 3-, 4-picoline +n-alkane (C6H14-C10H22) at 298.15 K have been compared with the Prigogine-Flory-Patterson theory and the Extended Real Associated Solution model estimations.

Excess heat of mixing of binary mixtures of pyridine withn-alkanes at 313.15 K

The molar excess enthalpies of binary mixtures of pyridine with C6–C9n-alkanes have been measured at 313.15 K in the entire composition range. The measuredHE values were compared with those calculated by means of the Prigogine-Flory-Patterson theory and by the ERAS method.

Enthalpic McMillan–Mayer coefficients from literature data on excess enthalpies. Application to solutions of alkanes in alkan-1-ols

A method is described to calculate enthalpic McMillan–Mayer pair-interaction coefficients from literature data on excess enthalpies of binary mixtures. The calculation also yields the enthalpies of solution at infinite dilution. A test of the method of mixtures, for which directly measured enthalpic interaction coefficients are known, shows that the method gives results of reasonable accuracy. However, the method is able to obtain a large number of interaction coefficients in a relatively simple manner. This makes interpretation and correlation analyses of the results possible, and this is illustrated by the application of the method to alkane + alkan-1-ol mixtures. Results for alkanes dissolved in alkan-1-ols are discussed in terms of the Savage–Wood group-additivity treatment using one parameter for each solvent. In addition we present an empirical relation which makes it possible to correlate 49 enthalpic interaction coefficients of 6 different alkanes dissolved in 10 different alkan-1-ols with only one adjustable parameter.

Thermodynamic properties of binary mixtures of 2,4-lutidine and iso-aliphatic alcohols

The molar excess enthalpies of binary mixtures of 2,4-lutidine with isopropanol, isobutanol and 2-butanol at 293.15 and 303.15 K, and withtert-butanol at 303.15 K, were measured over the whole composition range.

Calculation of excess enthalpies for binary mixtures of liquid metal halides

A semi-empirical equation, based on simple regular solution theory and involving only dispersion and charge–dipole interactions, is deduced for the excess enthalpy, HE, of a family of molten salt mixtures. The hard-core separation, λ, calculated from scaled particle theory, is adopted for the anion-cation separation in the melt. When the excess enthalpies at the equimolar composition, calculated from the derived equation, are compared with the experimental HE values available for 37 of the possible 40 binary alkali halide mixtures with a common anion, almost perfect agreement is obtained.