Excess molar volumes and viscosities of binary mixtures of cyclohexane and n-alkane at 298.15 K

Awwad, A.M. and Salman, M.A., 1986. Excess molar volumes and viscosities of binary mixtures of cyclohexane and n-alkane at 298.15 K. Fluid Phase Equilibria, 25: 195-208.Excess molar volumes, viscosities, excess molar viscosities, and excess molar activation energies of viscous flow were determined for binary mixtures of cyclohexane + n-pentane, + n-hexane, + n-heptane, + n-octane, + n-nonane, + n-decane, + n-dodecane, + n-tetradecane and + n-hexadecane at 298.15 K. The effect of orientational order of n-alkane on solution molar volumes and viscosities is investigated as well as the adequacy of the Flory theory and free volume theories used to predict solution molar volumes and viscosities. For longer n-alkanes V^E, η^E and ΔG*^E are positive and associated with the orientational order.     

Excess molar volumes of methylcyclohexane+benzene, +methylbenzene, +1,4-dioxane,and +tetrahydrofuran at 303.15 K

Excess molar volumes V_m^E as function of mole fraction x for methylcyclohexane + benzene, + methylbenzene, + 1,4-dioxane, and + tetrahydrofuran are reported at 303.15 K. The excess molar volumes are positive and indicate the presence of weak interactions.     

Excess molar volumes and viscosities of binary mixtures of 1,2-diethoxyethane with chloroalkanes at 298.15 K

Excess molar volumes (V _m ^E ) and viscosities (η) of the binary mixtures of 1,2-diethoxyethane with di-, tri- and tetrachloromethane have been measured at 298-15 K and atmospheric pressure over the entire mole fraction range. The deviations in viscosities (δlnη) and excess energies of activation (δG*^E) for viscous flow have been calculated from the experimental data. The Prigogine-Flory-Patterson (PFP) model has been used to calculateV _m ^E , and the results have been compared with experimental data. The Bloomfield and Dewan model has been used to calculate viscosity coefficients and these have also been compared with experimental data for the three mixtures. The results have been discussed in terms of dipole-dipole interactions between 1,2-diethoxyethane and chloroalkanes and their magnitudes decreasing with the dipole character of the molecules. A short comparative study with results for mixtures with polyethers and chloroalkanes is also described.     

Excess volumes for trichloroethene + benzene, + toluene, + p-xylene, + tetrachloromethane,and + trichloromethane at 303.15 K

Excess volumes V^E for trichloroethene (CCl₂CHCl) + benzene, + toluene, + p-xylene, + tetrachloromethane, and + trichloromethane have been measured at 303.15 K, by direct dilatometry. V^E has been found to be positive for trichloroethene + benzene, and + trichloromethane, and negative for trichloroethene + toluene, and + p-xylene. For trichloroethene + tetrachloromethane V^E is positive at low mole fractions of C₂HCl₃ and negative at high mole fractions.     

Excess molar volumes of binary mixtures of γ-butyrolactone and a glycol at 303.15 K

Excess molar volumes at 303.15 K for the binary mixture of ethylene glycol+, diethylene glycol+, triethylene glycol+ and tetraethylene glycol+ γ-butyrolactone were determined from precise density measurements over the whole mole fraction range. The excess molar volumes are positive over the whole mole fraction range for ethylene glycol and diethylene glycol systems. For triethylene glycol and tetraethylene glycol systems, V^E curves are sigmoid with a positive lobe at low mole fraction of glycol and a negative lobe at high mole fraction. The excess molar volumes V^E, results are interpreted qualitatively in terms of several opposing effects.     

Excess molar volumes of 1-alcohol + aliphatic monoethers at 298.15 K

Excess molar volumes V^E at 298.15 K and atmospheric pressure for 1-propanol and 1-hexanol + butyl methyl ether, + dipropyl ether or + dibutyl ether with a vibrating-tube densimeter. The V^E are negative over the whole mole-fraction range and nearly have been calculated from densities measured symmetrical for all the systems investigated. For each monoether, the V^E decreases as the chain length of the 1-alcohol increases. For each 1-alcohol, the V^E increases as the chain length of the symmetrical di-n-alkyl ethers increases. Moreover, for the butyl methyl ether (an asymmetrical monoether), the V^E is more positive than of the immediately higher symmetrical dipropyl ether. These results, together with previously published excess molar enthalpies H^E, suggest the formation of hydrogen bonds between the functional group (---OH) of the 1-alcohol and the (---O---) atoms of the monoethers.     

Excess molar volumes of carboxylic acid mixtures: binary mixtures of formic,acetic, propionic,n-pentanoic and iso-pentanoic acids at 298.15 K

Systematic measurements of density were performed in six binary mixtures of carboxylic acids. Derived from the densities the excess molar volumes V^E are always positive, with the exception of the formic acid+acetic acid system where V^E is negative for x<0.75 and positive for mixtures rich in formic acid. The extremal values of V^E are about −0.06 and +0.02 cm² mol⁻¹. As a rule, the excess molar volume curves are slightly asymmetrical with respect to composition having the maximal values of about 0.15 cm³ mol⁻¹ in the formic acid+propionic acid system; 0.10 cm³ mol⁻¹ in the acetic acid+ propionic acid system; 0.35 cm³ mol⁻¹ in the acetic acid+n-pentanoic acid system; 0.65 and 0.62 cm³ mol⁻¹ in the systems of n-pentanoic and iso-pentanoic acids with formic acid. A qualitative interpretation of the presented results is given taking into account almost complete dimerization of carboxylic acids and the formation of mixed dimers of these acids.     

Excess molar enthalpies at 298.15 k of the binary mixtures

We have determined the excess molar enthalpies H _m ^E at 298.15 K and normal atmospheric pressure for the binary mixtures containing tert-butyl methyl ether (MTBE)+(methanol, ethanol, 1-propanol, 1-pentanol) using a Calvet microcalorimeter. This revised version was published online in July 2006 with corrections to the Cover Date.     

Excess volumes and excess enthalpies of cyclohexanone with alkanes,benzene, toluene and tetrachloromethane at 298.15 K

Excess volumes and excess enthalpies have been measured for binary liquid mixtures of cyclohexanone with n-hexane, n-heptane, 2,2,4-trimethylpentane, benzene toluene and tetrachloromethane at 298.15 K. The results have been discussed in terms of the difference in molecular shape and specific interactions between unlike molecules. The Prigogine—Patterson—Flory equation of state theory has been used to evaluate the free volume and interactional contributions of the excess properties, and to predict excess volumes and excess enthalpies. The calculated values of V^E and H^E are in qualitative agreement with the experimental data in all the systems.     

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.     

Excess molar volumes and viscosities of mixtures of some n-alkoxyethanols with dialkyl carbonates at 298.15 K

Excess molar volumes V_m^E and viscosities η have been measured as a function of composition at atmospheric pressure and 298.15 K for nine {an alkoxyethanol+dimethyl carbonate (C₃H₆O₃), diethyl carbonate (C₅H₁₀O₃), or propylene carbonate (C₄H₆O₃)} mixtures. The alkoxyethanols were 2-methoxyethanol (CH₃OCH₂CH₂OH), 2-(2-methoxyethoxy)ethanol {CH₃(OCH₂CH₂)₂OH}, and 2-{2-(2-methoxyethoxy)ethoxy}ethanol {CH₃(OCH₂CH₂)₃OH}. The V_m^E for each of the carbonate mixtures studied decrease in magnitude as the polar head group of the alkoxyethanol increases. From the experimental results, deviation in the viscosity (Δlnη) have been calculated. The experimental results have been correlated using the Redlich–Kister equation to estimate the coefficients and standard errors. The experimental and calculated quantities are used to discuss the mixing behaviour of the components.     

Excess molar enthalpies of binary mixtures for (tributyl phosphate+methanol/ethanol) at 298.15 K

Excess molar enthalpies of binary mixtures for tributyl phosphate (TBP)+methanol/ethanol were measured with a TAM air Isothermal calorimeter at 298.15 K and ambient. The results for xTBP+(1–x)CH₃OH are negative in the whole range of composition, while the values for xTBP+(1–x)C₂H₅OH change from positive values at low x to small negative values at high x. The experimental results have been correlated with the Redlich–Kister polynomial. IR spectra of the mixtures were measured to investigate the effect of hydrogen bonding in the mixture.     

Excess properties of binary mixtures hexane,heptane, octane and nonane with benzene,toluene and ethylbenzene at T = 283.15 and 298.15 K

Densities, speeds of sound and the refractive indices of binary systems containing alkanes (hexane, heptane, octane and nonane) with aromatic compounds (benzene, toluene and ethylbenzene) at T = 283.15 and 298.15 K under atmospheric pressure were determined over the whole composition range. From the experimental results, the derived and excess properties (excess molar volumes, isentropic compressibility, excess molar isentropic compressibility and refractive index deviations) at T = 283.15 and 298.15 K were calculated and satisfactorily fitted to the Redlich–Kister equation.     

Excess molar volumes and excess molar enthalpies of binary mixtures for 1,2-dichloropropane + 2-alkoxyethanol acetates at 298.15 K

The excess molar volumes and excess molar enthalpies over the whole range of composition have been measured for the binary mixtures formed by 1,2-dichloropropane (1,2-DCP) with three 2-alkoxyethanol acetates at 298.15 K and atmospheric pressure using a digital vibrating-tube densimeter and an isothermal calorimeter with flow-mixing cell, respectively. The 2-alkoxyethanol acetates are ethylene glycol monomethyl ether acetate (EGMEA), ethylene glycol monoethyl ether acetate (EGEEA), and ethylene glycol monobutyl ether acetate (EGBEA). The of the mixture has been shown positive for EGMEA, ‘S-shaped’ for EGEEA, being negative at low and positive at high mole fraction of 1,2-DCP, and negative for EGBEA. All the values for the above mixtures showed an exothermic effect (negative values) which increase with increase in carbon number of the 2-alkoxyethanol acetates, showing minimum values varying from −374 J mol⁻¹ (EGMEA) to −428 J mol⁻¹ (EGBEA) around 0.54–0.56 mol fraction of 1,2-DCP. The experimental results of and were fitted to Redlich–Kister equation to correlate the composition dependence of both excess properties. In this work, the experimental excess enthalpy data have been also correlated using thermodynamic models (Wilson, NRTL, and UNIQUAC) and have been qualitatively discussed.     

Studies of viscosity and excess molar volume of binary mixtures: 4. 1-Alkanol + tri-n-butylamine mixtures at 303.15 and 313.15 K

The excess molar volume V^E, the viscosity deviation Δη and the excess Gibbs energy of activation ΔG^1E of viscous flow are calculated from density and viscosity measurements of six mixtures of 1-propanol, 1-butanol, 1-pentanol, 1-heptanol, 1-octanol and 1-decanol with tri-n-butylamine over the entire range of mole fractions at 303.15 and 313.15 K. The values of V^E of all six systems are very large and negative. Except for 1-propanol+tri-n-butylamine, the magnitude of negative deviations in viscosity increases with chain length of alkanol. The results have been explained considering mixed associated species of type A_iB involving alkanol (A) with tri-n-butylamine (B) through OH⋯N bonds. The viscosity data have been correlated with the equations of Grunberg and Nissan, Tamura and Kurata, Hind, McLaughlin and Ubbelohde, Katti and Chaudhri, McAllister, Heric, and of Auslaender.     

Studies of viscosity and excess molar volume of binary mixtures: 2. Butylamine+1-alkanol mixtures at 303.15 and 313.15 K

The excess molar volume V^E, viscosity deviation Δη, excess viscosity η^E, and excess Gibbs energy of activation ΔG*^E of viscous flow have been investigated from the density ρ and viscosity η measurements of eight binary mixtures of butylamine with ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol and decanol over the entire range of mole fractions at 303.15 and 313.15 K. The viscosity data have been correlated with the equations of Grunberg and Nissan [L. Grunberg, A.H. Nissan, Nature 164 (1949) 799–800], Tamura and Kurata [M. Tamura, M. Kurata, Bull. Chem. Soc. Jpn. 25 (1952) 32–37], Hind et al. [R.K. Hind, E. McLaughlin, A.R. Ubbelohde, Trans. Faraday Soc. 56 (1960) 328–334], Katti and Chaudhri [P.K. Katti, M.M. Chaudhri, J. Chem. Eng. Data 9 (1964) 442–443], McAllister [R.A. McAllister, AIChE J. 6 (1960) 427–431], Heric [E.L. Heric, J. Chem. Eng. Data 11 (1966) 66–68], and of Auslaender [G. Auslaender, Br. Chem. Eng. 10 (1965) 196]. The systems studied exhibit very strong cross association through strong O–H⋯N bonding between –OH and –NH₂ groups. As a consequence of this strong intermolecular association, all eight systems have very large negative V^E. Except butylamine+ethanol mixture, the magnitude of negative deviations in viscosity increases with chain length of alkanol.