Molecular interaction studies in ternary liquid mixture of dimethylacetamide using ultrasonic technique at 308 K

The experimental density (ρ) and ultrasonic velocity (U) for ternary mixture containing dimethylacetamide (DMAC), acetone and diethyl ether at frequencies 2, 4, 6 and 8 MHz have been measured at temperature 308 K. These data are used to compute adiabatic compressibility (K_s), intermolecular free length (L_f), acoustic Impedance (Z), molar volume (V_m), molar sound velocity (R), molar compressibility (B), available volume (V_a), Lennard-Jones potential repulsive term exponent (n), relative association (R_A), interaction parameter (χ) and some excess thermo acoustic parameters for whole range of concentration of DMAC and are interpreted to elucidate molecular interaction occurring in the liquid mixture.     

Acoustical and Viscometric Studies of CdCl2 and KCl in Aqueous-Acetone Co-Solvent Between 25 and 45°C

Abstract

Ultrasonic velocity of CdCl₂ and KCl in co-solvent of Acetone and Water is measured at different concentrations from 298.15 K to 318.15 K using single crystal interferometer; operating at frequency of 2 MHz. Various acoustical parameters such as adiabatic compressibility (β_s), specific impedance (Z), apparent molar compressibility (Ø_K), relative association (R _A), Rao's molar sound function (R), molar compressibility (W), free volume (V _f) have been calculated. Results throw light on the solute-solvent and solute-solute interactions. Effect of temperature variation on these interactions has also been discussed.     

Acoustical parameters of toluene + chloroform + cyclohexane mixtures at 303.15, 308.15, and 313.15 K

Ultrasonic velocity, density and viscosity of the ternary mixture of toluene + chloroform + cyclohexane, were measured at 303.15, 308.15, and 313.15 K. The thermodynamically parameters such as adiabatic compressibility (??), intermolecular free length (L _f), free volume (V _f), internal pressure (?? _i ), acoustic impedance (Z), molar sound velocity (R), and molar compressibility (W) have been obtained from the experimental data for all the mixtures, with a view to investigate the exact nature of molecular interaction. Adiabatic compressibility and intermolecular free length decrease with increase in concentration and temperature. The other parameters show almost increasing concentration of solutes. These parameters have been further used to interpret the molecular interaction part of the solute and solvent in the mixtures.     

Acoustical Parameters of CuCl-KCl System in Acetonitrile-Water Solvent Mixture

Abstract

Ultrasonic velocity (U) and density (d) have been measured for CuCl-KCl in. acetonitrile water co-solvent at various temperatures from 298.15 to 318.15K. The adiabatic compressibility (β_ad), molar compressibility (β) specific acoustical impedance (Z), Rao Number (R) and Van der Waals Constant (b) have been computed. The variation of d, β_ad, β, Z, R and b with molarity of CuCl have been studied. The association between the components and the formation of complexes are treated.     

Ultrasonic study on some monosaccharides in aqueous media at 298.15 K

The ultrasonic velocity (U), density (ρ) and viscosity (η) at 298.15 K have been measured in the binary systems of monosaccharides (glucose, fructose and galactose) in aqueous medium. The acoustical parameters such as adiabatic compressibility (β), free length (L_f), free volume (V_f), internal pressure (π_i), acoustical impedance (Z), relative association (R_A), molar sound velocity (R) and molar sound compressibility (W) are calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures.     

Intermolecular interactions in dioxane-water solutions of substituted coumarins according to ultrasonic data

Density, ultrasonic velocity of pure dioxane (Dx) and ligands, 4,6-dimethyl-7-hydroxycoumarin (L₁), 6-ethyl-7-hydroxy-4-methylcoumarin (L₂), and 3-chloro-7-hydroxy-4-methylcoumarin (L₃) in different percent of Dx-water mixture have been investigated at 303.15 K. Acoustical parameters such as adiabatic compressibility (β), intermolecular free length (L _f ), acoustical impedance (Z), relative association (R _A ), apparent molar compressibility (Φ_β), and apparent molar volume (Φ _V ) have also been evaluated from the experimental data of density and ultrasonic velocity. An excellent correlation between a given parameters is observed at all percent of dioxane-water and the result suggests nature of intermolecular interactions between the components.     

Studies on thermo-acoustic parameters of poly(ethylene glycol)- 400 at different temperatures

The ultrasonic velocity and density have been measured at different temperatures between 299 and 363 K for the pure liquid sample, poly(ethylene glycol) with average molecular mass 400 g mol^?1 (PEG 400). From these, isentropic compressibility (β), intermolecular free length (L _f), acoustic impedance (Z), molar volume (V _m), Schaff’s available volume V _a(s), molar sound velocity (R _a), and molar compressibility (W) have been evaluated. The variations of these parameters with the temperature of the sample have been studied. Data so obtained are employed to compute other thermodynamic parameters. Variations in various parameters with respect to temperature are discussed in the light of the results obtained.     

Ultrasonic studies of polysaccharide (pectin) in aqueous media at 298.15 K

The ultrasonic velocity, density and viscosity of pectin in aqueous medium were measured at 298.15 K. The acoustical parameters such as adiabatic compressibility (β), free length (L _f), free volume (V _f), internal pressure (π_i), acoustical impedance (Z), and relative association (R _A), Rao’s constant (R) and Wada’s constant (W) are calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures. Further, some more acoustical parameters such as relaxation time (τ), absorption coefficient (α/f ²) and relaxation strength (r) are calculated with various percentage of pectin has been studied which reveals interaction between the solvent and the polymer (pectin) at various concentration of the polymer. The observed values suggested the solute-solvent interaction is favored.     

Acoustical studies of some derivatives of 4-amino antipyrene in 1,4-dioxane and dimethylformamide at 318.15 K

For three derivatives of 4-amino antipyrene, density, viscosity and ultrasonic velocity are measured at 318.15 K in 1,4-dioxane (DO) and dimethylformamide (DMF). From these experimental data, various acoustical properties such as specific impedance (Z), isentropic compressibility (κ_s), Rao’s molar sound function (R_m), the van der Waals constant (b), molar compressibility (W), intermolecular free length (L_f), relaxation strength (r), relative association (R_A), free volume (V_f), etc. and apparent molar volume and apparent molar compressibility were calculated. The results are interpreted in terms of molecular interactions occurring in the solutions. It is observed that in 1,4-dioxane solutions, solute–solute interactions exist whereas solvent–solute interactions predominant in DMF system.     

Acoustical studies on fructose with enzyme amylase in aqueous media at 298.15 K

Ultrasonic velocity (U), density (ρ), and viscosity (η) measurements have been carried out in three ternary mixtures of fructose with amylase in aqueous medium at 298.15 K. The experimental data have been used to calculate some derived parameters such as acoustical impedance (Z), relative association (R _a ), Rao’s constant (R _R), Wada’s constant (W), relaxation time (τ), relaxation amplitude (α/f ²), relaxation strength (r), and some excess thermodynamical properties like excess adiabatic compressibility (β ^E ), excess free length (L _f ^E ) excess free volume (V _f ^E ), excess internal pressure (π _i ^E ), and excess acoustical impedance (Z ^E ). The above parameters have been evaluated and discussed in light of molecular interactions in the mixture.     

Apparent molar volume and apparent molar adiabatic compressibility of 2-hydroxy-5-methyl acetophenone in <Emphasis Type="Italic">N,N</Emphasis>-dimethylformamide at different temperatures

The speed of sound and density of 2-hydroxy-5-methyl acetophenone in dimethylformamide have been measured over the range of temperatures 25–40 °C. From the experimentally determined data, values of apparent molar volume (V _ϕ), adiabatic compressibility (β_s), apparent molar adiabatic compressibility (K _s,ϕ) and their limiting values have been computed. Values at infinite dilution provide information regarding solute–solvent interaction. The density and velocity increases with increase in concentration and decreases with increase in temperature. These results have been analyzed in terms of molecular interactions between acetophenone and dimethylformamide.     

Acoustical and excess thermodynamic studies of mixtures of 2-pyrrolidone with 1,3-propanediol and water as well as 1,3-propanediol with water at 308.15 K

The density (ρ), viscosity (η) and ultrasonic velocity (u) of three mixtures consisting of 2- pyrrolidone with 1,3-propanediol (PD) and water and also of PD and water have been measured as a function of mole fraction at 308.15 K. The experimentally collected data has been used to calculate the excess molar volume (V^E), deviation in viscosity (Δη), deviation in ultrasonic velocity (Δu), isentropic compressibility (κ_s), deviation in isentropic compressibility (Δκ_s) and excess Gibbs free energy of activation (ΔG*^E). The Redlich–Kister polynomial equation has been used to fit the derived parameters. The variation in excessive thermodynamic properties as a consequence of possible molecular interactions is discussed.     

Investigation on molecular interaction studies of binary mixture of DEHPA and petrofin at 298.15 K

The present article reports the values of density (ρ₁₂), molar volume (V₁₂), apparent molar volume (V_?), dielectric constant (?₁₂), molar polarisation (P₁₂) and molar refraction (R₁₂) of binary mixture of di-2-ethylhexyl phosphoric acid (DEHPA) and petrofin at various compositions. The excess properties such as V^E, ?^E, ΔnD, P^E and R^E have been calculated to throw light on the existence of interaction between the DEHPA and petrofin molecules in the binary mixture. The values of V^E and R^E were found to be positive while the values of ?^E, ΔnD and P^E were negative over the entire composition showing weak interaction between the two unlike molecules in the mixture. The Kirkwood-correlation factors (g) have been evaluated to know the nature of interaction prevailing in DEHPA and petrofin. These data provide useful information regarding interaction between self-associated protic DEHPA and non-associated petrofin which in turn helps the metallurgist to use DEHPA diluted with petrofin as effective solvent in extraction of metals.     

Acoustical studies of schiff bases in 1,4-dioxane and dimethylformamide at 318.15 K

The density, viscosity, and ultrasonic velocity of solutions of two schiff bases in 1,4-dioxane and dimethylformamide (DMF) were measured at 318.15 K. Various acoustical properties, such as the specific impedance (Z), isentropic compressibility (κ_s), Rao’s molar sound function (R _m), van der Waals constant (b), molar compressibility (W), intermolecular free length (L _f), relaxation strength (r), relative association (R _A), and free volume (V _f), were calculated. The results were interpreted in terms of molecular interactions occurring in the solutions. Published in Russian in Zhurnal Fizicheskoi Khimii, 2006, Vol. 80, No. 7, pp. 1206–1210. The text was submitted by the authors in English.     

Thermo-physical properties of the binary mixture of benzaldehyde with bromobenzene at 303.15, 308.15, and 313.15?K

The values of density, viscosity, and ultrasonic velocity for the binary liquid mixture of benzaldehyde with bromobenzene have been measured over the entire range of composition at 303.15, 308.15, and 313.15?K. These values have been used to calculate the excess molar volume (V ^E), deviation in viscosity (????), deviation in velocity (?U), deviation in isentropic compressibility (??? _s), excess internal pressure (???), excess intermolecular free length (?L _f), and excess acoustic impedance (?Z). McAllister??s three-body-interaction model is used for correlating kinematic viscosity of binary mixtures. The excess values were correlated using the Redlich?CKister polynomial equation to obtain their coefficients and standard deviations. The thermo-physical properties (density, viscosity, and ultrasonic velocity) under the study were fitted to the Jouyban?CAcree model.     

Thermophysical and thermoacoustical properties of benzaldehyde mixtures with ethylbenzene at 303.15, 308.15, and 313.15 K and a pressure of 0.1 MPa

Ultrasound velocity (u), density (ρ) and viscosity (η) measurements of benzaldehyde + ethylbenzene mixtures have been carried out at 303.15, 308.15, and 313.15 K. These values have been used to calculate the excess molar volume (V ^E), deviation in viscosity (δη), and deviation in isentropic compressibility (δβ_s), deviations in ultrasound velocity (δu), excess free volume (δV _f), excess intermolecular free length (δL _f) and excess Gibbs free energy of activation of viscous flow (δG ^E). McAllister’s three body interaction model is used for correlating kinematic viscosity of binary mixtures. The excess values were correlated using the Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. The thermophysical properties under the study were fit to the Jouyban-Acree model. The observed variation of these parameters helps in understanding the nature of interactions in these mixtures. Further, theoretical values of the ultrasound speed were evaluated using theories and empirical relations.     

Viscous synergy and antagonism,excess molar volume,isoentropic compressibility and excess molar refraction of ternary mixtures containing tetrahydrofuran,methanol and six membered cyclic compounds at 298.15 K

The densities (ρ), viscosities (η), sound speeds (u) and refractive indices (n _D) of seven ternary mixtures of cyclic ether (tetrahydrofuran), methanoland cyclic compounds; benzene, toluene, chlorobenzene, nitrobenzene, anisole, cyclohexane and cyclohexanone are determined over the entire range of composition at 298.15?K. From the experimental observations, viscosity deviation (Δη), the viscous synergy and antagonism, synergic and antagonic index are derived by the equations developed by Kalentunc-Gencer and Peleg [G. Kalentunc-Gencer and M. Peleg, J. Texture Stud. 17, 61 (1986)] and Howell [N.K. Howell, Presented at the Proceedings of the Seventh International Conference, Wales, 1993], respectively. Excess molar volume (V ^E), excess isoentropic compressibility (ΔK _S) and excess molar refraction (ΔR) have been calculated from the experimentally measured density, sound speed and refractive index values. The excess Gibb's free energy of activation (ΔG ^E) has also been calculated. The results are discussed and interpreted in terms of molecular package and specific interaction predominated by hydrogen bonding.     

Ultrasonic investigation on aqueous polysaccharide (starch) at 298.15 K

The ultrasonic velocity, density and viscosity at 298.15 K have been measured in the binary system of starch in aqueous medium. The acoustical parameters such as adiabatic compressibility (β), free length (L_f), free volume (V_f), internal pressure (π_i), acoustical impedance (Z), relative association (R_A), Rao’s constant (R), Wada’s constant (W), classical absorption coefficients (α/f²), relaxation time (τ) and relaxation strength (r) are calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures.     

Thermodynamic studies of some 1,2,4-triazole derivatives in DMF and THF solutions at 308.15 K

Some new 1,2,4-triazole derivatives have been synthesized and characterized by TLC, IR, NMR and mass spectra. Densities, viscosities and ultrasonic velocities of these compounds have been measured over the wide composition range at 308.15?K in dimethyl formamide (DMF) and tetrahydro furan (THF). From these data, various acoustical and thermodynamic parameters (C.V. Suryanarayana, J. Kuppuswamy. J. Acoust. Soc. Ind., 4, 75 (1976); H. Erying, M.S. John, Significance of Liquid Structures, Wiley, New York (1969); G.K. Johri, R.C. Misra. Acustica, 56, 66 (1989)) were evaluated. Some of these parameters are isentropic compressibility (κ_s), intermolecular free length (L _f), relaxation strength (r), relative association (R _A), Rao's molar constant (R _m), van der Waal's constant (b), molar compressibility (W), internal pressure (π), free volume (V _f), solvation number (S _n) etc. The behavior of solutions of these compounds in DMF and THF are explained from the evaluated parameters.     

Temperature dependence of density, viscosity, ultrasonic velocity, and other properties of substituted pyrazoles in acetone-water mixtures

The density, viscosity and ultrasonic velocity of some substituted pyrazoles viz. 5-(2-hydroxyphenyl)-3-(pyridin-3-yl)-4-benzoylpyrazol, 5-(2-hydroxyphenyl)-3-(3-nitrophenyl)-4-(3-pyridinoyl)-pyrazol, 5-(2-hydroxyphenyl)-3-(3-nitrophenyl)-4-benzoylpyrazol and 5-(2-hydroxyphenyl)-3-phenyl-4-(3-pyridinoyl)-pyrazole have been measured in 70: 30 (vol/vol) acetone-water mixture at 298, 303, 308, and 313 K for 0.01 mol dm^?3 concentration of pyrazoles. The acoustical parameters such as adiabatic compressibility (??_s), relative association (R _A), specific acoustic impedance (Z), apparent molar volume (?_v), apparent molar adiabatic compressibility (?_K), and intermolecular free length (L _f) were calculated from the experimental densities and velocities. The changes in acoustical properties have been used to interpret the molecular interactions in solutions. The activation energies of viscous flow of pyrazole solutions were determined from the data of viscosity at different temperature.