Ultrasonic velocities and isentropic compressibilities of N-methyl-2-pyrrolidone with ketones and branched alcohols at 303.15 K

The ultrasonic sound velocities and densities are measured for the binary mixtures of N-methyl-2-pyrrolidone (NMP) with ketones and branched alcohols at 303.15?K. The ketones include methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone and cyclohexanone. The branched alcohols include 2-propanol, 2-methyl-1-propanol, 3-methyl-1-butanol, 2-butanol and 2-methyl-2-propanol. The ultrasonic sound velocity data were used to compute isentropic compressibilities (k _s). The deviations in the value of k _s from ideal value were computed. Except cyclohexanone all the binary mixtures formed by NMP with ketones at 303.15?K exhibit negative deviation from ideal behaviour over the entire range of composition. Cyclohexanone with NMP exhibit positive deviation over the entire range of composition. An inversion in the sign of Δk _s from positive to negative was observed for 2-propanol system and negative deviation was observed in four binary mixtures formed by NMP with other branched alcohols at 303.15?K. The ultrasonic sound velocities of these mixtures have been analysed is terms of Free Length Theory (FLT), Collision Factor Theory (CFT) and Nomoto's relation.     

Excess molar volumes,viscosity deviations and isentropic compressibility changes in glycylglycine–NiCl2 aqueous ethanol mixtures

The densities, viscosities and ultrasonic velocities for glycylglycine–NiCl₂ in aqueous ethanol mixtures have been studied in the temperature range 288.15–318.15 K. The excess molar volumes, viscosity deviations and changes in isentropic compressibility for the binary mixtures have been calculated and discussed in terms of hydrogen bonding and structure-breaking effect. The computed results are fitted to the Redlich–Kister polynomial. The results clearly indicate that there is a strong association in the mixtures studied.     

Measurement of Some Thermodynamic and Acoustic Properties of Binary Solutions of N,N-Dimethylformamide with 1-Alkanols at 30°C and Comparison with Theories

Densities, and ultrasonic velocities, uof binary mixtures of N,N-dimethylformamide (DMF) + methanol, + ethanol, + 1-propanol, + 1-butanol, + 1-pentanol, and + 1-hexanol have been measured at 30°C. The ultrasonic velocities have been compared with values calculated from the free-length theory ( FLT) due to Jacobson and collision-factor theory ( CFT) due to Schaaffs. The measured data are used to compute adiabatic compressibility (k _s), deviation in adiabatic compressibility (k _s), intermolecular free length (L _f), molar volume (V _m), and available volume (V _a). The excess molar volume ( V _m ^E) and excess free length (L _f ^E) are also evaluated. For all systems, these results were satisfactorily correlated by the Redlich–Kister polynomial. These parameters are used to discuss dissociation of the self-associated 1-alkanol molecules and the formation of aggregates between unlike molecules through C=O...H–O hydrogen bonding.     

Volumetric, Ultrasonic and Transport Properties of Binary Liquid Mixtures Containing Dimethyl Formamide at 303.15 K

Excess volumes （v^E）, ultrasonic velocities （u）, isentropic compressibility （△Ks） and viscosities （η） for the binary mixtures of dimethyl formamide （DMF） with 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,2,4-trichlorobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-nitrotoluene and m-nitrotoluene at 303.15 K were studied. Excess volume data exhibit an inversion in sign for the mixtures of dimethyl formamide with 1,2- and 1,3-dichlorobenzenes and the property is completely positive over the entire composition range for the mixtures of dimethyl formamide with 1,2,4-trichlorobenzene, o-nitrotoluene and m-nitrotoluene. On the other hand, the quantity is negative for the mixtures of dimethyl formamide with chlorotoluenes. Isentropic compressibility （Ks） has been computed for the same systems from precise sound velocity and density data. Further, deviation of isentropic com- pressibility （△Ks） from ideal behavior was also calculated. AKs values are negative over the entire volume fraction range in all the binary mixtures. The experimental sound velocity data were analysed in terms of Free Length Theory （FLT） and Collision Factor Theory （CFT）. The viscosity data were analysed on the basis of corresponding state approach. The measured data were discussed on the basis of intermolecular interactions between unlike molecules.     

Studies of some Thermodynamic Properties of Binary Mixtures of Acrylonitrile with Aromatic Ketones at <Emphasis Type="Italic">T</Emphasis>=308.15 K

Densities (ρ), ultrasonic speeds (u), and excess molar volumes (V_m^EV_{\mathrm{m}}^{\mathrm{E}}) of binary mixtures of some aromatic ketones in acrylonitrile have been measured over the entire range of composition at 308.15 K. From these experimental results, parameters such as the isentropic compressibilities K _S , interaction parameter χ ₁₂, Flory parameters, A _i coefficients, standard deviations σ(Y ^E), and molar sound velocities R _m have been estimated. The excess functions were fitted to Redlich-Kister type polynomial equations. The experimental ultrasonic speeds were analyzed in terms of Jacobson’s Free Length Theory (FLT), Schaaff’s Collision Factor Theory (CFT), Nomoto’s relation, and Van Dael’s ideal mixture relation. The intermolecular Free Length L _f, and available volume V _a, have been calculated from the FLT, CFT, and thermoacoustic approaches for binary systems of acetophenone and propiophenone in acrylonitrile at 308.15 K.     

Thermodynamic properties of binary mixtures containing 1-alkanols

Densities (ρ) of pure liquids and their mixtures have been measured at 303.15 and 313.15 K and atmospheric pressure over the entire composition range for the binary mixtures of benzylalcohol with 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol by using Rudolph Research Analytical digital densitometer (DDM-2911 model). Further, the ultrasonic sound velocities for the above said mixtures were also measured at 303.15 and 313.15 K. The measured density data were used to compute excess molar volumes (V ^E) and these were compared with the values obtained by Hwang equation. Isentropic compressibility (κ _S) and excess isentropic compressibilities (κ _S ^E ) were evaluated from experimental sound velocity and density data. Moreover, the experimental sound velocities were analyzed in terms of theoretic models namely, collision factor theory and free length theory. The experimental results were discussed in terms of intermolecular interactions between component molecules.     

Molecular Interaction in Binary Mixtures of Tri-N-Butyl Phosphate (TBP) and Aliphatic Alcohols-Effect of Free Volume and Internal Pressure

Abstract

The ultrasonic velocity, density and viscosity in binary mixtures of TBP with a number of aliphatic primary alcohols viz. methanol, ethanol, 1-hexanol, 1-heptanol, 1-octanol and 1-decanol have been measured at frequency 3 MHz and at temperature 303.16 K. The data are used to compute excess internal pressure and excess enthalpy in these mixtures. The results corroborate the findings of these authors from dielectric studies that the interaction is maximum in 1 heptanol-TBP system and microheterogeneous β-clusters with antiparaliel orientation of dissimilar molecules predominate in it.     

Thermodynamic properties of non-electrolyte solutions

Experimental densities (ρ) and ultrasonic sound velocities (u) for the binary mixtures of toluene, o-chlorotoluene, m-chlorotoluene, and p-chlorotoluene with 1-octanol were measured over the entire composition range at T = (298.15, 303.15, and 308.15) K and at a pressure of 0.1 MPa. Excess volumes (V ^E), isentropic compressibilities $ (\kappa_{\text{s}} ) $ , and excess isentropic compressibilities $ (\kappa_{\text{s}}^{\text{E}} ) $ were calculated using the measured experimental densities and ultrasonic sound velocities of the pure liquids and their mixtures. The experimental data were discussed in terms of intermolecular interactions between component molecules. The measured excess properties were correlated with the Redlich–Kister polynomial equation.     

Isentropic compressibilities of (amide + water) mixtures: A comparative study

The density and ultrasonic velocity of aqueous solutions of formamide (FA), N-methylformamide (NMF), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), pyrrolidin-2-one (PYR), N-methyl-2-pyrrolidinone (NMP), and their pure phases have been measured at 298.15 K and atmospheric pressure. Densities and ultrasonic velocities in pure amides have been also measured at the temperature range 288.15 K to 308.15 K for the computation of their thermal expansivities. Isentropic compressibility, intermolecular free length, relative association, apparent molar compressibility, as well as the excess quantities, ultrasonic velocity, isentropic compressibility, intermolecular free length, have been evaluated and fitted to the Redlich–Kister type equation. The deviation from ideal mixing law in ultrasonic velocity is positive while the deviations in isentropic compressibility and intermolecular free length are negative for all (amide + water) mixtures. This behavior reveals the nature and the magnitude of intermolecular interactions between the amide–water molecules. The sequence of superimposed curves of various ultrasonic parameters vs. the amide mole fraction is related to the strength of interactions between the unlike molecules and the role of –CH₃ substitution in amides. The comparison of ultrasonic to volumetric properties reveals differences on the position of the extrema and their relation with the degree of substitution while the interpretation of these differences is discussed. Two different approaches on the computation of excess functions, applied in this work, brought out a difference in the magnitude of deviations and a partial reversion to the sequence of amides curves suggesting a different estimation in terms of deviations from ideal mixing law and therefore of the relative molecular interactions.     

Thermodynamic and acoustic properties of binary mixtures of PEGDME 250 with 1-propanol and 1-butanol at 293, 303 and 313°K

ABSTRACT

The work presented in this paper deals with the study of thermodynamic properties of new working fluids for absorption machines, mainly for characterisation of absorbent–refrigerant pairs that could improve the cycle performance. The study of atomic motion in liquids plays an important role in understanding the solid-like behaviour of liquids. The accurate measurement of the energy changes due to scattering can be used to study the dynamical behaviour of liquids. Measurements of the ultrasonic velocity (u), density (ρ) and viscosity (η) for binary mixtures of polyethylene glycol 250 dimethyl ether with 1-propanol and 1-butanol have been made at three temperatures (T = 293, 303 and 313 K) over the entire composition range in order to investigate the nature of intermolecular interactions between the components of these liquid mixtures. Non-linear variation of derived quantities with the mole fraction supports the molecular interaction occurring between component molecules.     

Excess molar volumes and ultrasonic studies of dimethylsulphoxide with ketones at T = 303.15 K

Excess molar volumes (V^E) and ultrasonic sound velocities at T = 303.15 K and ambient pressure have been measured as a function of composition for the binary liquid mixtures of dimethylsulphoxide (DMSO) with ketones. The ketones studied in the present investigation include ethyl methyl ketone (EMK), diethylketone (DEK), methyl propyl ketone (MPK), methyl isobutyl ketone (MIBK), and cyclohexanone (CH). The V^E values were measured using a dilatometer and were positive over the entire mole fraction range for all systems except in the binary system DMSO with EMK where the V^E exhibits an inversion in sign. The experimental V^E values have been correlated using Redlich–Kister and Hwang et al. equations. The ultrasonic sound velocities for the above systems have been measured with a single crystal interferometer at a frequency of 3 MHz. The sound velocity (u) data have been used to calculate isentropic compressibility (K_s) and deviation in isentropic compressibility (ΔK_s) over the entire range of volume fraction. The sound velocity data have been predicted in terms of free length theory (FLT), collision factor theory (CFT), and Nomoto relation. The results reveal that all the theories gave a satisfactory estimate of the sound velocity. The deviations in values of isentropic compressibility (ΔK_s) were negative over the entire range of volume fraction in all the binary liquid mixtures. The results are interpreted with respect to possible molecular interactions between components.     

Excess Acoustical and Volumetric Properties and Theoretical Estimation of Ultrasonic Velocities in Binary Liquid Mixtures of 2-Chloroaniline with Acrylic Esters at 308.15 K

The ultrasonic velocities (u) and densities (??) for three binary mixture systems of 2-chloroaniline (CA) with ethyl acrylate (EA), butyl acrylate (BA), and 2-ethylhexyl acrylate (EHA) were measured over the entire mole fraction range at the temperature 308.15?K, including those of pure liquids. From these data, the deviations in ultrasonic velocity (??u), the excess molar volumes ( $V_{\mathrm{m}}^{\mathrm{E}}$ ), deviations in excess molar volume ( $\delta V_{\mathrm{m}}^{\mathrm{E}}$ ), deviations in isentropic compressibility (??k _S), excess intermolecular free lengths ( $L_{\mathrm{f}}^{\mathrm{E}}$ ), and excess acoustic impedances (Z ^E) have been calculated. The variations of these properties with solution composition are discussed in terms of molecular interactions among unlike molecules of the mixtures. The excess and deviation functions have been fitted to Redlich-Kister type polynomials and the corresponding standard deviations ??(Y ^E) have been calculated. The deviations and excess values were plotted against the mole fraction of CA over the whole composition range. The $V_{\mathrm{m}}^{\mathrm{E}}$ and ??k _S values are negative in the EA + CA and BA + CA systems but are positive in the EHA + CA system, which indicates the presence of specific interactions between unlike molecules. Further, theoretical values of the sound velocity in these mixtures have been evaluated using various theories and have been compared with experimental sound velocities to verify the applicability of such theories to the investigated systems. Two types of polynomial equations, f(x) and g(x), have been fitted to experimental values of ultrasonic velocities. The sound velocities obtained by these polynomials have extremely small deviations from the experimental values.     

Density, Viscosity, Velocity and Refractive Index of Binary Mixtures of Poly(Ethylene Glycol) 200 with Ethanolamine, m-Cresol and Aniline at 298.15 K

Densities, absolute viscosities, ultrasonic velocities and refractive indices of binary mixtures of poly(ethylene glycol) 200 with ethanolamine, m-cresol and aniline have been measured at 298.15 K, under atmospheric pressure, over the entire composition range. The experimental data have been used to calculate acoustic impedance, specific heat ratio and relative association for these binary mixtures. Excess molar volume, deviation in viscosity, deviation in refractive index, deviation in isentropic compressibility, excess acoustical impedance and excess Gibbs energy of activation for viscous flow have been plotted to determine the nature and extent of interaction present in the solutions. The results have been fitted to Redlich-Kister polynomial equation. The results have been explained in terms of specific intermolecular and intramolecular interactions present in the mixtures and are found to support each other. The isothermal compressibility for the binary mixtures was predicted by an equation based on Flory??s statistical theory and three rigid sphere equations.     

Excess molar volumes and ultrasonic studies of N-methyl-2-pyrrolidone with ketones at T = 303.15 K

Excess molar volumes (V^E) and ultrasonic studies at T = 303.15 K and atmospheric pressure have been measured over the whole composition range for the binary mixtures of N-methyl-2-pyrrolidone (NMP) with ketones. The ketones studied in the present investigation include methyl ethyl ketone (MEK), diethylketone (DEK), methyl propyl ketone (MPK), methyl isobutyl ketone (MIBK), and cyclohexanone (CH). The V^E values were measured using a dilatometer and were negative over the entire mole fraction range for NMP with MEK, DEK, MPK, and MIBK and were positive for NMP with CH. The ultrasonic sound velocities for the above systems were measured with a single crystal interferometer at a frequency of 3 MHz. The sound velocity (u) results have been used to calculate isentropic compressibility (K_s) and deviation in isentropic compressibility (ΔK_s) over the entire range of volume fraction. The sound velocity results have been predicted in terms of free length theory (FLT), collision factor theory (CFT), and Nomoto relation. The results reveal that all the theories gave a satisfactory estimate of the sound velocity. The deviation values of the isentropic compressibilities (ΔK_s) were negative over the entire range of volume fraction in all the binary liquid mixtures except in the binary system NMP with CH, where we observed positive ΔK_s values. The results are interpreted on possible molecular interactions between components.     

Ultrasonic velocity measurements for the ternary mixtures chlorobenzene + n-hexane + linear aliphatic alkane (C7–C8) at 298.15 K

The ultrasonic velocity of the ternary mixtures chlorobenzene + n-hexane + (n-heptane or n-octane) at 298.15?K and atmospheric pressure, has been measured over the whole concentration range. The corresponding change of isentropic compressibility was computed from the experimental data. The results were fitted by means of the Nagata equation, such parameters being gathered. The experimental ultrasonic velocities have been analyzed by theoretical procedures, an adequate agreement between the experimental and theoretical values both in magnitude and sign being obtained, despite the high nonideal trend of mixtures.     

Thermodynamics of mixtures containing alkoxyethanols. Part xxiii. Speed of sound predictions and ultrasonic studies of hydroxyether + organic solvent mixtures

The ability of different models to predict speeds of sound, u, of binary mixtures formed by alkoxyethanol and octane, oxaalkane or propylamine has been examined. The models applied are: the free length theory (LFT), the collision factor theory (CFT), and equations such as those proposed by Nomoto, Junjie or Van Dael. Collision factor theory, Nomoto's and Junjie's equations provide similar deviations between experimental and calculated u, which is represented quite accurately by these three models. Poorer predictions are obtained when applying the Junjie's equation to propylamine systems, probably due to the existence of strong interactions between unlike molecules in such mixtures. In contrast, slightly better u predictions from CFT are obtained for the systems 2-methoxyethanol + polyether, or hydroxyether + propylamine. The good u predictions obtained using Nomoto's equation remark the validity of Rao's assumption on additivity of molar sound velocity contributions from atoms, atom groups and chemical bonds of the constituent molecules. Discrepancies between experimental and calculated u are larger when using FLT than those obtained from CFT, Nomoto's or Junjie's equations. This has been ascribed to association and size or shape effects. The linear dependence on the molar fractions of the component liquids of the Rao's and Wada's constants suggests that there is no complex formation in the investigated mixtures, and that the interactions present in such systems are of dipolar type.     

Thermodynamics of concentrated electrolyte mixtures. II. Densities and compressibilities of aqueous NaCl−CaCl2 at 25 °C

Densities and ultrasonic velocities of NaCl–CaCl₂ aqueous mixtures at 25 °C have been measured for the ionic strength range I=0.30–20.0. Where NaCl solubility permitted, both properties were measured over the range of compositions from pure NaCl to pure CaCl₂ at constant I. Apparent molar volumes and apparent molar compressibilities of the mixtures were calculated. The Pitzer form of the specific interaction theory is used to predict the properties of the binary mixtures from the properties of the single salt solutions. It provides a good fit over the full range of ionic strength for apparent molar volumes but a much inferior fit for compressibilities. It is also clear that in the high ionic strength range, explicit mixing parameters must be included for an excellent fit.     

Kalidoss—Jacobson Free Length Theory Applied to Binary Liquid Mixtures of CCI4+Toluene/Aniline/oCresol m-cresol p-Cresol

Abstract

Ultrasonic velocities and intermolecular free lengths in binary liquid mixtures of CC4 with toluene, aniline, o-cresol, m-cresol and p-cresol have been calculated theoretically, at different compositions and at temperature 298 K, based on Free Length Theory as revised recently by Kalidoss. It is observed that there is a close agreement of calculated velocities with experimental ones. The shape and thermostatic state picture built up in this formulation could be considered as a good representation of molecular state.     

Dielectric relaxation in OH—O bond complexes

Abstract

The dielectric absorption of the mixtures of Phenol with Acetone and Ethyl methyl ketone having different concentration ratios (3:1, 2:1, 1:1, 1:2 and 1:3) has been determined at microwave frequency 9.8 GHz, at 33°C. The dielectric data have been analyzed, to yield relaxation times and dipole moments, using Higasi method and Higasi, Koga and Nakamura method. All the mixtures yielded high values of the distribution parameter indicating the flexible nature of the OH-O type hydrogen bonding. The high values of the relaxation times and dipole moments give confirmative results for the association of the phenol with these electron donar molecules in all mixtures investigated.