Isentropic Compressibility Changes Research Articles

Volumetric and Ultrasonic Study of Mixtures of Benzyl Alcohol with 1-Propanol, 2-Propanol, and 1,2-Propandiol, 1,3-Propandiol and T-butanol

Densities and speeds of sound for five binary mixtures of benzylalcohol with 1,3-propandiol, 1- propanol, 2- propanol, 1,2-propandiol and phenylethnol were measured over the entire range of composition and at five temperatures from 298.15K to 323.15K at 5K interval and atmospheric pressure using a vibrating u-tube densimeter (DSA 5000). Besides, the densities for pure compounds in the above-mentioned temperature range were measured. The experimental densities were used to calculate the excess molar volumes, isentropic compressibility changes, the excess thermal expansion coefficients, and the excess partial molar volumes at infinite dilution, The results have been used to discuss the nature and strength of intermolecular interactions in these mixtures. The calculated excess and deviations quantities are correlated with the third-order Redlich–Kister equation. As a final work we modeled the experiment results by using TM and PR EOSs. This is clear that the results with TM EOS are more acceptable than PR EOS. TM and PR EOS can successfully predict density and excess molar volume. And are unable to predict speed of sound.

Investigations of the reduced Redlich–Kister excess properties of 1,4-dioxane + isobutyric acid binary mixtures at temperatures from 295.15 to 313.15 K

ABSTRACTExcess molar volumes and refractive index, molar refraction deviations and isentropic compressibility changes in 1,4-dioxane + isobutyric acid binary mixtures (from 295.15 to 313.15) K. were calculated from experimental density, refractive index and sound velocity data presented in previous work. Here, these experimental values were used to test the applicability of the correlative reduced Redlich–Kister equation as well as their corresponding relative functions which are important to reduce the effect of temperature and, consequently, to reveal the effects of different types of interactions. The results of these observations have been interpreted in terms of structural effects of the solvents. The correlating equation recently proposed by Belda, has also been applied to the present system in order to assess the validity of this equation and to give thermodynamic limiting partial molar quantities interesting to evaluate solute–solvent interaction.

Ultrasonic Investigation of α-Amino Acids with Aqueous Solution of Urea at Different Temperatures: A Physicochemical Study

The present paper reflects the ultrasonic investigations for exploring the inter-ionic interactions of various concentrations of α-amino acids such as L-Arginine, L-lysine monohydrochloride, and L-histidine in aqueous solutions of urea over a wide ranges of temperatures (298.15 to 323.15) K under atmospheric pressure. It also represent the detail showing that molecular interactions between the a-amino acids and urea has much dissociation of proteins in the solvent mixture. The study of ultrasonic speed and sound velocity were successfully preformed on the liquid ternary mixtures. With the help of the above mentioned parameter, the values of isentropic compressibility, change in isentropic compressibility , relative change in isentropic compressibility , relative association , specific acoustic impedance , and apparent molal isentropic compressibility were calculated. These parameters have been examined in term of the molecular associations such as ion-ion, ion-solvent, solute-solvent, solute-solute etc., and briefly described in terms of the structure-making ability corresponding to a-amino acids in the urea. Efforts have been taken to explore the dependency of the outcomes related to temperature and concentration.

Ultrasonic studies of different saccharides in α-amino acids at various temperatures and concentrations

The present experimental investigation was carried out in order to explore the possible molecular inter-ionic interactions of saccharides namely, d-glucose, sucrose and maltose in aqueous solutions of α-amino acid such as l-arginine and l-lysine monohydrochloride at 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15K. Experimental values of ultrasonic speed (U) and density (ρ) were carried out on the liquid ternary mixtures of l-arginine+saccharides+water. These measured experimental data have been used to calculate parameters such as isentropic compressibility (Ks), change in isentropic compressibility (∆Ks), relative change in isentropic compressibility (∆Kr), relative association (RA), specific acoustic impedance (Z), and apparent molal isentropic compressibility (ϕks). The negative values of apparent molal isentropic compressibility indicates that the water molecules in the bulk solution are more compressible than the water around ionic charges of l-arginine and l-lysine monohydrochloride respectively. The present work revealed the possible molecular associations such as solute-solute and solute-solvent etc. and eventually discussed about the behaviour of solute (saccharides) in the given system. In these systems, strong solute-solvent interactions are observed and found to increase with an increase in temperature.

Ultrasonic speeds, refractive indices, and densities of dimethoxymethane + aliphatic alcohols (C1–C4) at (298.15 and 303.15) K with COSMO-RS and ERAS analyses

The ultrasonic speeds, refractive indices, and densities of binary mixtures dimethoxymethane+aliphatic alcohols (C1–C4) were determined. The excess quantities for the binary mixtures are fitted to the Redlich–Kister polynomials. The observed excess molar volumes are rationalized in terms of the intermolecular force and geometry contributions of the constituent molecules. The intermolecular forces are discussed using accepted theories and the more recent conductor-like screening model (COSMO). The extended real associating solution (ERAS) model is also utilized in the analysis of excess molar volumes. The σ-profile of dimethoxymethane and alcohols are computed with COSMO-RS and interpreted to be not supportive of earlier interpretations of hydrogen bonds in the energetics. Sign changes in excess molar volume and excess isentropic compressibility are discussed and rationalized in detail quantitatively. Sellmeier's equation is used to quantitatively rationalize the measured refractive indices and a consistency with regard to sign and sign changes of the other measured excess quantities can be deduced.

Comparative study of density, sound velocity and refractive index for (water + alkali metal) phosphates aqueous systems at T = (298.15, 303.15, and 308.15) K

The density, speed of sound and refractive index for (water+alkali metal) (Li, Na and K) were measured over their entire composition range at T=(298.15,303.15 and 308.15) K. The isentropic compressibility, change and relative change in isentropic compressibility, apparent molal compressibility, acoustic impedance, speed of light and molar refractions were calculated using values of the experimental density, speed of sound, and refractive index, respectively. Redlich–Kister smoothing linear equation was used for obtaining limiting sound velocity, isentropic compressibility and refractive index data. Ion–ion, ion-dipolar, solute–solvent and intermolecular interactions have been interpreted with thermodynamic properties.

Investigations of the reduced Redlich–Kister equations for correlating excess properties of N,N-dimethylacetamide + 2-ethoxyethanol binary mixtures at temperatures from 298.15 K to 318.15 K

Excess molar volumes, viscosity deviations and isentropic compressibility changes in N,N-dimethylacetamide + 2-ethoxyethanol binary mixtures at (298.15 K, 308.15 K and 318.15 K) were calculated from experimental density, viscosity and sound velocity data presented in previous work. Here these experimental values were used to test the applicability of the correlative reduced Redlich–Kister equation and the Herraez equation as well as their corresponding relative functions. These relative functions are important to reduce the effect of temperature and, consequently, to reveal the effects of different types of interactions. Limiting excess partial molar volume were deduced from different methods, activation parameters and partial molar Gibbs energy of activation of viscous flow against compositions were investigated. The results of these observations have been interpreted in terms of structural effects of the solvents. The correlating equation recently proposed by Belda, has also been applied to the present system in order to assess the validity of this equation.

The Relative Reduced Redlich–Kister Equations for Correlating Excess Properties of N,N-Dimethylacetamide + Water Binary Mixtures at Temperatures from 298.15 K to 318.15 K

Excess molar volumes, viscosity deviations, and isentropic compressibility changes in N,N-dimethylacetamide + water binary mixtures at (298.15, 308.15 and 318.15) K were calculated from experimental density, viscosity and sound velocity results presented in previous work. Here these experimental values were used to test the applicability of the correlative reduced Redlich–Kister equation and the recently proposed Herraez equation, as well as their corresponding relative functions. Their correlation ability at different temperatures, and the use of different numbers of parameters, are discussed for the case of limited experimental data. The relative functions are important to reduce the effect of temperature and, consequently, to reveal the effects of different types of interactions. Values of the limiting excess partial molar volume at infinite dilution were deduced using different methods. Also, the activation parameters and partial molar Gibbs energy of activation of viscous flow were analyzed as functions of composition. Correlation between the two Arrhenius parameters of viscosity in all composition domains show the existence of two distinct behaviors, separated by a stabilized structure over a short range of mole fractions from (0.2 to 0.3) in N,N-dimethylacetamide. In this regard, a correlation equation recently proposed by Belda has also been applied to the present system for deriving molar volume properties, in order to assess the validity of the proposed equation,

Isentropic compressibilities of the mixture chlorobenzene + n-hexane + (n-heptane or n-octane) at 298.15 K

In this work, the applicability of the free length and the collision factor theories (FLT and CFT, respectively) to predict multicomponent changes of isentropic compressibilities is analysed and compared. To this end, appropiate expansions for ternary mixtures were derived from the original works, and then applied to a mixture containing unlike compounds in terms of functional molecular groups. Experimental data of excess molar volumes from open literature and new experimental isentropic compressibilities of the mixture chlorobenzene + n-hexane + (n-heptane or n-octane) were used to compute the parameters. A good accuracy was obtained when ternary prediction is attempted in this partially soluble mixture at different temperatures by the collision factor theory. These results show the versatility of this model for estimation in complex multicomponent mixtures with phases splitting.

The relative reduced Redlich–Kister equations for correlating excess properties of N,N-dimethylacetamide + 2-methoxyethanol binary mixtures at temperatures from 298.15 K to 318.15 K

Knowledge and prediction of physicochemical properties of binary mixtures is of great importance for understanding intermolecular interactions. The literature shows that most such systems exhibit non-linear behaviour. Excess molar volumes, viscosity deviations and isentropic compressibility changes in N,N-dimethylacetamide + 2-methoxyethanol binary mixtures at 298.15, 308.15 and 318.15 K were calculated from experimental density, viscosity and sound velocity data presented in previous work. Here these experimental values were used to test the applicability of the correlative reduced Redlich–Kister equation and the recently proposed Herráez equation as well as their corresponding relative functions. Their correlation ability at different temperatures, and the use of different numbers of parameters, is discussed for the case of limited experimental data. These relative functions are important to reduce the effect of temperature and, consequently, to reveal the effects of different types of interactions. Limiting excess partial molar volume at infinite dilution were deduced from different methods, activation parameters and partial molar Gibbs energy of activation of viscous flow against compositions were investigated. The results of these observations have been interpreted in terms of structural effects of the solvents. In this frame, a correlating equation is recently proposed by Belda and in order to assess the validity of the proposed equation, it has also been applied to the present system for molar volume properties.

Volumetric, acoustic and spectroscopic studies for binary mixtures of ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) with alkoxyalkanols at T = (288.15 to 318.15) K

Densities and speeds of sound have been measured for the binary mixtures of ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF 6] with ethylene glycol monoethyl ether (EGMEE), diethylene glycol monoethyl ether (Di-EGMEE), triethylene glycol monoethyl ether (Tri-EGMEE) over the whole composition range at atmospheric pressure. Experimental densities have been used to estimate excess molar volumes, V E . Changes in isentropic compressibility, Δκ s have been estimated by using experimental speed of sound and density values. Excess properties were fitted to the Redlich–Kister polynomial equation to obtain the binary coefficients and the standard errors. The molecular scale interactions between ionic liquid and alkoxyalkanols have been investigated through 1H NMR spectroscopy. NMR chemical shifts for hydroxyl group of alkoxyalkanols and their deviations show hydrogen bonding interactions of varying strengths between ionic liquid and alkoxyalkanol in their binary mixtures.

Topological and Thermodynamic Studies for Binary Mixtures of 1,4-Dioxane with Anilines at 308.15 K

Excess molar volumes, V E, excess molar enthalpies, H E, speeds of sound, u, and vapor-liquid equilibrium data of 1,4-dioxane (1) + aniline or N-methyl aniline or o-toluidine (2) binary mixtures have been measured as a function of composition at 308.15 K. Isentropic compressibility changes that occur for mixing, $\kappa_{S}^{\mathrm{E}}$ , and excess Gibb’s energies, G E, have been determined by employing speeds of sound and vapor-liquid equilibrium data. The $V^{\mathrm{E}}, H^{\mathrm{E}},\kappa_{S}^{\mathrm{E}}$ and G E values have been estimated by (i) graph theory and (ii) the Prigonone-Flory-Patterson theory (PFP). It was observed that values of $V^{\mathrm{E}}, H^{\mathrm{E}},\kappa_{S}^{\mathrm{E}}$ and G E predicted by graph theory compare well, relative to the PFP theory, with their corresponding experimental values.

Isentropic compressibilities of chlorobenzene + n-hexane + (n-undecane or n-dodecane) at 298.15 K

In this study, the applicability of the Free Length and the Collision Factor theories to predict multicomponent changes of isentropic compressibilities is analysed and compared. To this end, appropriated expansions for ternary mixtures were derived from the original studies where these theories are developed, and then applied to a mixture containing unlike compounds in terms of functional molecular groups. Experimental data of excess molar volumes from open literature and new experimental isentropic compressibilities of the mixture chlorobenzene + n-hexane + (n-undecane or n-dodecane) were used to compute the parameters. A good accuracy was obtained when ternary prediction is attempted in this partially soluble mixture at different temperatures by the both methods. These results show the versatility of the models for estimation in complex multicomponent mixtures.

Ultrasonic Study of Basic α-Amino Acids in Different Acetate Salt Solutions at Different Temperatures

The ultrasonic velocity (U), has been measured for three α-amino acids, namely L-lysine monohydrochloride, L-arginine and L-histidine in solutions (1 mol/L aqueous) of sodium acetate (SA), potassium acetate (PA) and calcium acetate (CA) at different temperatures (303.15, 308.15, 313.15, 318.15 and 323.15 K). With the help of these results various ultrasonic derived parameters, viz. isentropic compressibility (κs), change in isentropic compressibility (Δκs), relative change in isentropic compressibility (Δκr), specific acoustic impedance (Z), relative association (RA), and apparent molal compressibility (ϕ) have been estimated. The results have been interpreted in the light of intermolecular interactions between solute and solvent.

Acoustical and Compressibility Parameters of Glycylglycine−FeCl3in Aqueous Ethanol Mixture atT= (293.15, 303.15, and 313.15) K

Ultrasonic velocity measurement is a reliable procedure that allows quick and easy determination of solvent concentrations in mixtures. This paper presents data of ultrasonic velocities and isentropic compressibilities of (glycylglcyine−FeCl3) in aqueous ethanol mixture at T = (293.15, 303.15, and 313.15) K. Various acoustical parameters were calculated, because of their importance in the study of specific molecular interactions. A less-compressible phase of the fluid and a closer packing of molecules is observed with changes in the intermolecular free length. Quantitative investigation suggests that the mixing of ethanol with an aqueous glycylglycine−FeCl3 solution causes the rupture of hydrogen bonds, with increasing δκS and Lf values (where the former represents the change in isentropic compressibility and the latter represents the intermolecular free length). Theoretically computed values of isentropic compressibility in the studied mixture using different models indicate the superiority of the very complex procedure.

Volumetric and Ultrasonic Investigation of Glycylglycine in Aqueous FeCl3 Solutions

Viscosity, ultrasonic velocity and density measurements have been carried out for glycylglycine in aqueous FeCl3 solution as a function of molality at T=288.15 K, 298.15 K and 308.15 K. The experimental data have been used to derive properties such as isentropic compressibility (κ S ), change in isentropic compressibility (Δκ S ), relative change in isentropic compressibility (Δκ S /κ 0), apparent molar compressibility, volume and their limiting apparent molar quantities along with the constants S K , S V and viscosity B-coefficient. The obtained thermodynamic properties have been discussed in terms of molecular interactions.

Thermodynamic Properties of Binary Mixtures of Tetrahydropyran with Anilines at 308.15 K

Excess molar volumes, V E , excess molar enthalpies, H E , speeds of sound, u, and vapor-liquid equilibrium data of tetrahydropyran (1) + aniline or N-methylaniline or 2-methylaniline (2) binary mixtures have been measured over the entire mole fraction range at 308.15 K. Speeds of sound and vapor-liquid equilibrium data have been utilized to predict isentropic compressibility changes of mixing, κ E S , and excess Gibb's free energy, G E . The observed V E , H F , κ E S , and G E data have been analyzed in terms of Graph theory. It has been observed that V E , H E , κ E S and G E predicted by Graph theory compare well with their corresponding experimental values.

Ultrasonic Studies of 4-Aminobutyric Acid in Aqueous Salbutamol Sulphate Solutions at Different Temperatures

Ultrasonic speeds of 4-aminobutyric acid in 0.0041, 0.0125 and 0.0207 mol·kg −1 aqueous salbutamol sulphate (SBS) solutions are measured at 308.15, 313.15 and 318.15 K. Isentropic compressibility K S, change in isentropic compressibility Δ K S, relative change in isentropic compressibility (Δ K S/ K 0 S), apparent molal compressibility K ø, limiting apparent molal compressibility K 0 ø, transfer limiting apparent molal compressibility δ K 0 ø, hydration number n H, pair and triplet interaction parameters K AS, K ASS are estimated. The above parameters are used to interpret the solute-solute and solute-solvent interactions of 4-aminobutyric acid in the aqueous salbutamol sulphate solutions.

Excess molar volumes, viscosity deviations and isentropic compressibility changes in glycylglycine–NiCl 2 aqueous ethanol mixtures

The densities, viscosities and ultrasonic velocities for glycylglycine–NiCl 2 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.

Excess thermodynamic properties of binary mixtures of ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) with alkoxyalkanols at several temperatures

Physical properties such as densities, ρ, speed of sound, u, and refractive indices, n, have been measured for the binary mixtures of ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF 6] with diethylene glycol monomethyl ether (DEGMME), propylene glycol monomethyl ether (PGMME) and propylene glycol monoethyl ether (PGMEE) over the whole composition range at atmospheric pressure. Experimental densities have been used to estimate excess molar volume V m E. Changes in isentropic compressibility, Δ κ S , have been estimated by using experimental speed of sound and density values. Experimental refractive indices values have been used to calculate the deviation in refractive indices, Δ φ n, and molar refraction, Δ x R. Excess properties are fitted to the Redlich–Kister polynomial equation to obtain the binary coefficients and the standard errors. Apparent molar volume and apparent molar compressibility at infinite dilution, V φ, i ∞ and K φ, i 0 have been calculated to gain information about solute–solvent interactions. The results are compared with our earlier studies concerning the binary mixtures of [bmim][PF 6] with alkoxyethanol or poly ethers.