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In the present work, density, ρ and speed of sound, u measurements have been performed, for binary mixtures of two synthesized Bronsted-acidic ionic liquids namely N,N,N-triethyl-4-sulfobutaneammonium hydrogensulfate, [N222(C4SO3H)][HSO4] and N,N,N-triethyl-4-sulfobutaneammonium trifluoromethanesulfonate, [N222(C4SO3H)][CF3SO3] with water and DMSO as solvents. Experimental measurements have been carried out at variable concentrations of ILs in the temperature range of (293.15 to 328.15) K with the constant interval of 5 K and at atmospheric pressure. Using experimentally measured density and speed of sound data, apparent molar volume, Vϕ and apparent molar isentropic compressibility, Ks, ϕ and limiting apparent molar expansion, Eϕ∞ have additionally been derived for the studied binary solutions. Apparent molar property data were fitted to the Redlich-Mayer type equation from which corresponding derived properties i.e. apparent molar volume and apparent molar isentropic compressibility at infinite dilutions, Vϕ∞ and κs, ϕ∞ were attained. Magnitude of these derived properties and corresponding empirical parameters were evaluated in the scope of understanding the nature of interactions prevailing among ions of ILs as well as ions and solvents.

Densities and refractive indices of three naphthyl hydroxamic acids, N -1-naphthyl- o -ethoxybenzohydroxamic acid (NEBHA), N -1-naphthyl- o -methylbenzohydroxamic acid ( N - o -MBHA) and N -1-naphthyl- p -methylbenzohydroxamic acid ( N - p -MBHA) were determined in ethanol under atmospheric pressure at T = (298.15 to 313.15 K). This study was undertaken to determine molar volume, V , specific molar volume, V S , apparent molar volume, V ϕ , apparent molar volume at infinite dilution, V ϕ 0 , and slope, S V ⁎ , based on the Masson's equation. The apparent molar expansibility at infinite dilution, ϕ E 0 , thermal expansion coefficient, α 2 , and Hepler's constant, ( ∂ 2 V ϕ 0 / ∂ T 2 ) P , have also been calculated from temperature dependence of V ϕ 0 . The steric parameters such as molar refraction, R M , and polarizability, α , have been determined from the refractive index, n , data. Excess molar volume, V E , excess refractive index, n E , excess molar refraction, R M E , and vander Waal constant, b , have also been estimated. These parameters have been used to understand the solute–solute and solute–solvent interactions qualitatively.

In continuation of our previous works, using the density measurement, we studied some important volumetric properties such as: apparent molar volumes, standard partial molar volumes, limiting apparent molar volumes of transfer, and limiting apparent molar expansibility for the ternary (ionic liquids 1-Ethyl-3-methylimidazolium hydrogen sulfate [Emim][HSO4] / 1-Butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4] + D(−)fructose + water) at T = (293.15 to 313.15) K. By using the standard partial molar volumes and limiting apparent molar volumes of transfer, the nature of possible interactions in studied solutions are considered. Results demonstrated that for both studied ionic liquids, the Vφ values are increased with rising concentration of ionic liquids and temperature. Also by applying the first derivative of limiting apparent molar expansibility with respect to temperature, the structure maker ability of studied ionic liquids in aqueous D(−)fructose solutions are confirmed.

Drug interactions in presence of co-solute in aqueous solution have always created an interest in the mind of chemists. The physical properties give an idea of types of interactions taking place in aqueous solution. Volumetric and compressibility are the important physical properties. Keeping this in mind we have measured the densities ( ρ ) and speeds of sound ( u ) of sodium salicylate (NaSl) drug (0.01–0.1) mol·kg−1 in 0.06 mol·kg−1 aqueous sodium chloride solution and 0.06 mol·kg−1 myo-inositol as a function of temperature at T = (288.15, 298.15 and 308.15) K and atmospheric pressure. These values have been used to estimate the apparent molar volume of solute ( V ϕ ) , apparent molar isentropic compressibility ( κ s ) of solution and apparent molar isentropic compressibility ( κ ϕ ) of solute. The limiting apparent molar expansivity ( E ϕ 0 ) of solute and coefficient of thermal expansion ( α ∗ ) of sodium salicylate in aqueous binary and ternary solutions have also been obtained. Limiting values of apparent molar volume of solute ( V ϕ 0 ) and apparent molar compressibility of solute ( κ ϕ 0 ) were obtained from the plots V ϕ and κ ϕ as a function of molality and have been utilized in obtaining transfer volumes ( Δ tr V ϕ 0 ) and transfer compressibilities ( Δ tr κ ϕ 0 ) of sodium salicylate from water to 0.06 mol·kg−1 aqueous solutions of sodium chloride and myo-inositol at different temperatures. The co-sphere overlap model is used to interpret the values of ( Δ tr V ϕ 0 ) and ( Δ tr κ ϕ 0 ) . The Helper’s constant has been obtained. It indicates structure making ability of sodium salicylate in aqueous as well as in 0.06 mol·kg−1 aqueous sodium chloride and 0.06 mol·kg−1 aqueous myo-inositol solutions. The results obtained have been interpreted in terms of various interactions taking place among solute and solvent molecules.

Densities, ultrasonic speeds and viscosities of l -alanine and l -phenylalanine in water and in 0.1 mol·kg− 1 aqueous citric acid solutions were measured over the temperature range (298.15 to 313.15) K with interval of 5 K at atmospheric pressure. From these experimental data apparent molar volume, limiting apparent molar volume and the slope, partial molar expansibilities, adiabatic compressibility, transfer volume, Falkenhagen coefficient, Jone-Dole's coefficient, the temperature derivative of Jone-Dole's coefficient, intermolecular free length, specific acoustic impedance, and molar compressibility were calculated. The results are interpreted in terms of solute – solute and solute-solvent interactions in these systems. It has also been observed that l -alanine acts as a structure breaker whereas l -phenylalanine acts as a structure maker in aqueous citric acid.

Density, sound velocity and viscosity of DL-4-aminobutyric acid (GABA) in water and in aqueous sodium chloride solutions have been measured at (293.15, 298.15, 303.15, 308.15 and 313.15) K. The apparent molar volumes and the apparent molar compressibilities were calculated at each temperature from the experimental density and sound velocity data. Limiting values at infinite dilution of the partial molar volumes and the partial molar compressibilities of GABA in water and in aqueous sodium chloride solutions were determined through extrapolation at each temperature. The relative viscosity data were adjusted by a least-squares method to a second order equation as proposed by Tsangaris-Martin to obtain the viscosity B coefficients. The influence of temperature on the behaviour of viscosity and the volumetric properties is discussed in terms of molecular interactions. The results confirm that hydrophilic hydration is predominant for GABA in aqueous solution. The addition of NaCl leads to an increase of the partial molar properties at infinite dilution and the viscosity B-coefficients, suggesting that the sodium and the chloride ions interact directly with the zwitterion, reducing the electrostriction of water molecules.

Deep eutectic solvents (DESs) are derived from two or more salts as the hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs). In this work, DES namely allyltriphenyl phosphonium bromide-diethylene glycol (ATPPB-DEG) was prepared by using three molar ratios of 1:4, 1:10 and 1:16 salt to HBD. The volumetric properties of aqueous DESs, such as density, molar volume, isobaric thermal expansion, apparent molar volume and apparent molar expansibility were reported at several temperatures from 293.15 to 343.15 K. A mathematical equation, so-called Jouyban–Acree model (JAM), was used to correlate the experimental density and molar volume data of aqueous solution of DESs with respect to the concentration and temperature. The results disclosed that this model is an accurate and reliable model for the prediction of aqueous DES properties. The excess properties, such as excess molar volume and excess isobaric thermal expansion were reported and fitted to two different equations. In order to calculate the limiting apparent molar volume values, the apparent molar volume values were fitted into a Redlich–Mayer equation. By applying the Hepler equation, it was found that DESs with molar ratios of 1:4 and 1:10 are as structure-maker solutes, while the DES 1:16 is a structure-breaking solute in aqueous solutions at different temperatures.

The apparent molar volume ( V ∅ ) and isentropic compression ( K ∅ s ) of glycine, L-alanine and L-valine have been studied in (0.025, 0.05, 0.075 and 0.1) mol·kg−1 aqueous 1-butyl-4-methyl pyridinium iodide [ C 4 mpy ] I solutions over a range of temperatures (288.15, 293.15, 298.15, 303.15 and 308.15) K from the values of densities (ρ) and ultrasonic speeds (u) respectively. The limiting apparent molar volumes ( V ∅ 0 ) , and limiting apparent molar isentropic compressions ( K ∅ ,s 0 ) are obtained and have been interpreted in terms of solute-solvent and solute-solute interactions. The corresponding transfer quantities ( Δ V ∅ 0 and Δ K ∅ ,s 0 ) from water to aqueous solutions of [ C 4 mpy ] I have been interpreted by cosphere overlap model. Volumetric and acoustic parameters are used to understand mixing effects and other complex biological processes between head and side chain groups of amino acids and ionic liquid in aqueous solution. The decrease in hydration number with increase in temperature indicates the reduction in electrostriction.

Densities of the mixture {water (1) + N- methylurea (2)} in the concentration range to mole fraction x2 = 0.07071 (or to the solution molality concentration m2 = 4.22335 mol·kg–1) at atmospheric pressure in the temperature range from 274.15 to 333.15 K and compression k = ΔV/V0 at pressures to 100 MPa (10, 25, 50, 75, and 100) in the temperature range from 278.15 to 323.15 K (278.15, 288.15, 288.15, 308.15, 323.15) in the same concentration range were calculated in this study. The apparent molar volumes of N-methylurea Vϕ,2 and the partial molar volumes of both components V1 and V2 in the mixture, molar isothermal compressibilities KT,m, molar isobaric thermal expansions EP,m, and isochoric coefficients of thermal pressure β of the mixture were calculated. Moreover, volumetric measures for the infinitely dilute solution of N-methylurea solution were calculated: limiting partial molar volumes V2∞, the limiting partial molar isothermal compressibilities KT,2∞, and the limiting partial molar isobaric the...

Deep eutectic solvents (DESs) are derived from two or more salts as the hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs). In this work, DES namely allyltriphenylphosphonium bromide- triethylene glycol (ATPPB-TEG) was prepared by using three molar ratios; i.e.,1:4, 1:10, and 1:16 of salt to HBDs. The volumetric properties of aqueous mixture of DESs, such as density, molar volume, isobaric thermal expansion, apparent molar volume and apparent molar expansibility were reported at several temperatures from 293.15 to 343.15 K. A mathematical equation, namely Jouyban–Acree model (JAM), was used to correlate the experimental density and molar volume data. Furthermore, in order to calculate the limiting apparent molar volume values, the apparent molar volume values were fitted into a Redlich–Mayer equation. By applying Hepler equation, it was found that DESs 1:4 and 1:10 are as structure-maker solutes, while DES 1:16 is a structure-breaking solute in aqueous solutions.

In the present study, the combination of volumetric and acoustical studies is used to investigate the interactions of ethylene glycol, diethylene glycol, and triethylene glycol with sorbitol as a function of temperature. Densities and ultrasonic velocities of ethylene, diethylene, and triethylene glycol in (0.00, 0.01, 0.03, 0.05) mol·kg–1 aqueous solutions of sorbitol have been measured at temperatures T = (288.15, 298.15, 308.15, 318.15) K and experimental pressure p = 0.1 MPa. With the help of density data, the apparent molar volume Vϕ, the partial molar volume Vϕo, and the partial molar volumes of transfer ΔVϕo, from water to aqueous sorbitol solutions have been computed. The values for partial molar expansibility (∂Vϕ0/∂T)p and second order derivative (∂2Vϕ0/∂T2)p have also been determined. From ultrasonic velocity values, apparent molar isentropic compression Kϕ,s, partial molar isentropic compression Kϕ,so, and partial molar isentropic compression of transfer ΔKϕ,so, are evaluated. The computed val...

Densities (ρ) and speeds of sound (c) measurements of d (−)-ribose and d (+)-xylose in (0.2, 0.4, 0.6) mol·kg−1 aqueous solutions of trilithium citrate (TLC) have been carried out at different temperatures. The experimental results were used to calculate apparent molar and partial molar quantities, partial molar volumes and partial molar isentropic compression of transfer. The pair and triplet interaction coefficients are computed from transfer parameters. The partial molar expansibilities have also been calculated. The results have been interpreted in terms of prevailing interactions and structure making and breaking tendency of the solutes in aqueous solution of TLC.

In order to analyze the extent of solvation behaviour and stability of ascorbic acid (AA) in water or aqueous ionic liquid (IL) solutions, the knowledge of their thermodynamic properties is prerequisite which gives an appropriate idea about interactions involved in solutions. In addition, experimental and derived thermodynamic data is essential in effective process and product design involving these systems. In this report, we studied the volumetric and acoustic properties of AA in aqueous solution of synthesized IL, [HxTzm][CF 3 SO 3 ] i.e. (1-Hexyl-4-(4-sulfobutyl)-1H-1,2,4-triazol-4-ium trifluoromethanesulfonate) in temperature range of (293.15–328.15) K and at atmospheric pressure. Further, the experimentally measured thermodynamic properties were used to calculate apparent molar and partial molar properties, which elucidate the solvation behaviour of AA in presence of studied IL. Further, on the basis of the structural interaction model, various type of interactions which is stirring between AA and IL have been discussed in terms of partial molar properties at infinite dilution, transfer parameters and pair and triplet interaction coefficients.

In this investigation density, speed of sound and viscosity of l -histidine (0.015–0.135) mol kg− 1 in aqueous ketorolac tromethamine solutions (0.1–0.7) mol kg− 1 at various temperatures (293.15, 298.15, 303.15, 308.15 and 308.15) K and at atmospheric pressure were studied. These data were further used to calculate apparent molar volume, VΦ, limiting apparent molar volume, V°Φ, limiting apparent molar volume of transfer, V°Φ,tr, apparent molar isentropic compression, KΦ,S, limiting molar isentropic compression, K°Φ,S, limiting apparent molar isentropic compression of transfer, K°Φ,S,tr, hydration number, nH, Jones-Dole coefficient-B, B, viscosity B-coefficients of transfer, Btr and the activation parameters, ∆ μ°#1 and ∆ μ°#2. The results obtained from all these thermodynamic parameters were discussed in terms of solute-solute interactions and solute-solvent interactions on the basis of co-sphere overlap model and the transition state theory.

The volumetric and compressibility properties of l -serine and l -valine in the concentration range (0.0 to 0.2) mol kg− 1 in water and various saccharides (0.1 glucose, 0.1 sucrose and 0.1 lactose) mol dm− 3 have been studied over a temperature range of (293.15 to 313.15) K. The experimental data is used to obtain the apparent molar volume (Vϕ), limiting apparent molar volume (Voϕ), limiting apparent molar transfer volume (∆trVoϕ), as well as apparent molar compressibility (Ks,ϕ), limiting apparent molar compressibility (Kos,ϕ), limiting apparent molar transfer compressibility (∆trKos,ϕ), limiting partial molar expansibility (ϕoE), coefficient of thermal expansion (α), hydration number (nH) and taste behavior of amino acids. The results have been interpreted in terms of solute-solute and solute-solvent interactions. As the taste behavior is divided into four basic taste qualities in different ranges, so an effort has also been made to compare the taste behavior of the two amino acids in water and in aqueous solution of saccharides.

Ionic liquid 1-methyl-3-pentylimidazolium bromide have been synthesised and its extent of purity has been confirmed by characterisation techniques 1H NMR, 13C NMR, MASS and IR spectroscopy. By use of volumetric and acoustic methods the interaction of amino acids ( l -leucine and N-acetyl- l -leucine) and synthesised Ionic liquid 1-methyl-3-pentylimidazolium bromide have been studied as a function of temperature and concentration. Density and speed of sound of aqueous amino acids ( l -leucine and N-acetyl- l -leucine) in aqueous ionic liquid (0.005, 0.01, 0.03, 0.05) mol·kg− 1 as solvent have been determined at four different temperatures T = (288.15, 298.15, 308.15, 318.15) K. Using these experimental data apparent molar volumes (Vϕ), limiting apparent molar volume (Vϕ0), experimental slope (SV), standard partial molar volumes of transfer (ΔVϕ0), limiting apparent molar expansibilities (Eϕ°),apparent molar isentropic compression (κϕ , s), limiting apparent molar isentropic compression (κϕ , s0)and standard partial molar isentropic compression of transfer (Δκϕ , s0)have been evaluated. The pair and triplet interaction coefficient have also been calculated. The values of these parameters are used for interpretation in terms of solute-solute and solute-solvent interactions, ion hydrophilic, hydrophilic–hydrophilic and hydrophilic– hydrophobic interactions in the amino acid and ionic liquid solutions. The structure making or structure-breaking tendency of amino acids has been studied using these thermodynamic parameters.

Thermodynamic properties of l -threonine and l -valine in aqueous solution of 1-methyl-3-pentylimidazolium chloride, [C5mim][Cl] have been investigated by volumetric and ultrasonic properties at three different temperatures (T = (288.15, 298.15 and 308.15) K). Other properties at infinite dilution like apparent molar volume, Vϕ0 and the apparent molar isentropic compression Kϕ , S0, have also been calculated from the measured data. Conclusion drawn from volumetric and ultrasonic properties have been further supported by calculating apparent molar expansion, Eϕ0, Hepler's constant values, ∂ E ϕ 0 ∂ T P , hydration numbers, nH and specific volume, vϕ. The calculated parameters are worthwhile in studying structure nurturing, solvation as well as taste behavior on the basis of various kinds of interactions present in such solutions.

Densities and viscosities of glycine, L-alanine, L-valine, L-threonine and L-arginine in aqueous (0.1–0.5) mol·kg− 1 myo-inositol solutions were measured at T = (293.15, 303.15, 313.15 and 323.15) K and p = 0.101 MPa. The volumetric properties such as the apparent molar volume (Vφ), the limiting partial molar volume (Vφ0), the limiting partial molar volumes of transfer (ΔtrVφ0), the limiting apparent molar expansibility (E20), Hepler's constant and the isobaric thermal expansion coefficient (α2) were calculated through density. The viscometric properties such as the B-coefficient, the free energies of activation per mole of solvent (Δμ10 ≠) and solute (Δμ20 ≠) were obtained from the experimental viscosity data. The derived parameters hydration number and solvation number were also calculated through apparent molar volume and B-coefficient. From the volumetric and viscometric properties, the solute-solute and solute-solvent interactions in the studied systems were analyzed on the basis of co-sphere overlap model and transition state theory. Finally, the group contribution method was applied to calculate the contribution of (NH3+, COO−), CH2, OH and CNHNHNH2 of amino acids to Vφ0, B-coefficient and Δμ20 ≠.

The solvation behavior of ionic liquids containing a common, 1,1,3,3-tetramethylguanidinium cation and different anions, phenylacetate and cinnamate, in water is examined through apparent molar properties. These ionic liquids were chosen because of their versatile applications as environment-friendly solvent, catalyst, and for dissolution and stability of biomolecules. In order to understand the ion-ion and ion-solvent interactions and effect of anion in dilute aqueous solutions of studied ionic liquids, the experimental measurements of density and speed of sound have been carried out as a function of molality (0.01 to 0.2 mol·kg − 1 ) and temperature from 293.15 to 318.15 K. Experimental data have been used to calculate the apparent molar and other derived thermodynamic properties. Further, Redlich-Meyer equation has been employed to obtain the apparent molar volume and isentropic compressibility at infinite dilution and the empirical parameters which are crucial in understating the hydrophilic and hydrophobic nature of studied ionic liquids.

Densities, ρ, ultrasonic speeds, u and viscosities, ƞ of glycine and diglycine in water and 0.1 mol·kg− 1 aqueous citric acid solutions were measured over the temperature range (298.15 to 313.15) K at the interval of 5 K at atmospheric pressure. From these experimental data apparent molar volume ФV, limiting apparent molar volume ФVO and the slope SV, partial molar expansibilities ФEO, adiabatic compressibility β, transfer volume ФVOtr, Falkenhagen coefficient A, Jone- Dole coefficient B, the temperature derivative of B coefficient dB/dT, intermolecular free length (Lf), specific acoustic impedance (Z), and molar compressibility (W) were calculated. The results are interpreted in terms of solute–solute and solute-solvent interactions. It was observed that glycine and diglycine act as structure breakers in aqueous citric acid at different temperatures.

The density and speed of sound measurements have been carried out for some α-amino acids i.e. glycine, l -alanine and l -valine in aqueous diammonium hydrogen phosphate (DAP) at 10 K intervals, from 288.15 K to 318.15 K and experimental pressure p = 0.1 MPa. We have utilized the density and speed of sound data for determining the apparent molar and partial molar parameters concerning volumetric and compressibility properties. The group contribution of amino acids to partial molar volumes has also been perceived. The pair and triplet interaction coefficients obtained from partial molar volumes of transfer and partial molar isentropic compression of transfer illustrate the dominance of pairwise interactions. The possible molecular associations such as solute-solvent and solute-solute etc. are revealed by the present work and in due course, it has also been observed that all the amino acids in our present study, act as structure makers in aqueous solution of diammonium hydrogen phosphate (DAP). Apparent molar properties and partial molar properties anticipate the dominance of strong solute–solvent interactions over weak solute-solute in the studied ternary system.

Apparent molar volumes, V ϕ , and apparent molar heat capacities, C p,ϕ , were measured for aqueous solutions of neutral adenine (AdH) and adeninium chloride (AdH 2 Cl) at temperatures from 288.15 K to 363.15 K, and for sodium adeninate (NaAd) at temperatures from 283.15 K to 313.15 K. Density measurements used in the determination of the standard partial molar volume, V o , were made with a vibrating-tube densimeter at ambient pressure. Heat capacity measurements used in the determination of the standard partial molar heat capacity, C p o , were made with a twin fixed-cell, differential output, power compensating, temperature-scanning calorimeter at a pressure of 0.4 MPa. The contributions from minor equilibrium species were removed using Young’s Rule to yield values for the standard partial molar volume and heat capacities of the ionic species AdH 2 + (aq) and Ad − (aq), and the equilibrium mixture of neutral species AdH ∗ (aq). Semi-empirical equations describing the temperature dependence of V o and C p o for each species were fitted by regression to the experimental results. From these equations, the standard partial molar volume change Δ r V o m and heat capacity change Δ r C p o m for the ionization reactions were calculated. The standard partial molar volumes presented in this study for neutral adenine are the first to be experimentally determined at temperatures above 330 K, while the standard partial molar heat capacities are the first to be reported at temperatures above 298.15 K. The experimental values for the adeninium cation and adeninate anion are the first to be reported in the literature.

The densities and viscosities of four binary mixtures [1-amino-2-propanol + ethanol, N-(2-aminoethyl) ethanolamine + ethanol, 3-amino-1-propanol + ethanol, N-(2-aminoethyl)-1,2-ethanediamine + ethanol] were measured at T = 293.15, 303.15, 313.15, and 323.15 K. The volumetric and viscometric properties, such as excess molar volume VE, partial molar volume V, partial molar volume at infinite dilution V∞, apparent molar volume Vφ, viscosity deviation Δη, and activation energy for viscosity flow Ea, were calculated from the experimental densities and viscosities, respectively. The excess molar volume and viscosity deviation were correlated by the Redlich–Kister equation, and the volumetric and viscometric properties were analyzed on the basis of intermolecular interactions between alcohol amine and ethanol molecules.

Apparent molar volume, Vϕ, apparent molar isentropic compression, K ϕ,s and viscosity B-coefficients have been evaluated for one of the vitamins, thiamine hydrochloride (thiamine-HCl), in aqueous solutions of two carbohydrates, glucose and lactose, at temperatures (293.15–313.15) K from density, speed of sound and viscosity data. Accordingly, limiting apparent molar volume, V 0ϕ, was obtained from Redlich-Meyer equation whereas limiting apparent molar isentropic compression, K 0ϕ,s, was calculated on the basis of Debye-Huckel theory. The transfer parameters (ΔtrV 0ϕ, ΔtrK 0ϕ,s and ΔtrB) at infinite dilution, limiting apparent molar expansivity, E 0ϕ, Hepler's constant, (∂2V 0ϕ/∂ T2)P, thermal expansion coefficient, α, pair and triplet interaction coefficients and solvation number, Sn, have also been estimated. The viscosity B-coefficients and activation parameters have been obtained from Jones-Dole equation and transition state theory. The results have been discussed in terms of competing patterns of interactions prevailing in the solute and solvent.

Ionic liquid 1-methyl-3-pentylimidazolium bromide have been synthesised and confirmed by characterisation techniques H 1 NMR, C 13 NMR, MASS and IR spectroscopy. Density and speed of sound of aqueous amino acids (L-cysteine and N-acetyl- l -cysteine) in aqueous ionic liquid (0.005, 0.01, 0.03, 0.05) mol⋅kg −1 as solvent have been determined at four different temperatures T = (288.15, 298.15, 308.15, 318.15) K. Using these experimental data apparent molar volumes ( V ϕ ), limiting apparent molar volume ( V ϕ ° ), experimental slope ( S v ), standard partial molar volumes of transfer (Δ V ϕ 0 ), Limiting apparent molar expansibilities ( E ϕ ∘ ), apparent molar isentropic compression ( К ϕ,s ), limiting apparent molar isentropic compression ( κ ϕ , s 0 ) and standard partial molar isentropic compression of transfer (Δ κ ϕ , s 0 ) have been evaluated. The pair and triplet interaction coefficient have also been calculated. The values of these parameters are helpful for interpretation in terms of solute-solute and solute-solvent interactions, ion hydrophilic, hydrophilic–hydrophilic and hydrophilic–hydrophobic interactions in the amino acid and ionic liquid solutions. The structure making or structure-breaking tendency of amino acids has also been studied using these thermodynamic parameters.

Densities (ρ) and speeds of sound (c) of solutions of some α-amino acids such as glycine, l-alanine, and l-valine in aqueous ammonium dihydrogen phosphate (ADP) were measured at T = (288.15–318.15) K and experimental pressure p = 0.1 MPa. By using the experimentally measured densities, the apparent molar volume (Vϕ), the partial molar volume at infinite dilution (Vϕo), and partial molar volumes of transfer (ΔVϕo), from water to aqueous ADP have been calculated. Further, apparent molar isentropic compression (Kϕ,s), partial molar isentropic compression at infinite dilution (kϕ,so) and partial molar isentropic compression of transfer (ΔKϕ,so) were calculated from the ultrasonic speeds. The group contributions of amino acid to partial molar volumes have also been discerned. From partial molar volumes of transfer and partial molar isentropic compression of transfer, the pair and triplet interaction coefficients are attained. We have also intended partial molar expansion (∂Vϕo/∂T)p and second order derivative ...

Density and sound velocity data for aspartic acid and serine in water and in aqueous solution of anionic surfactant; Sodium dodecyl sulphate (SDS) were measured over a temperature range (303.15 K–313.15 K). Various volumetric and acoustical parameters including apparent molar volume (Φv), partial molar volume (Φvo), partial molar transfer volume, apparent molar isentropic compressibility (Φk), partial molar isentropic compressibility (Φok) and intermolecular free length (Lf) etc. for amino acid solutions in water and in aqueous surfactant (SDS) solutions were calculated from the measured data of density and sound velocity. The abovementioned calculated parameters have been used to explore the amino acid-surfactant interactions. Values of apparent molar volume are positive at all temperatures and are increasing with increasing temperature and amino acids concentrations. Similarly, intermolecular free length decreases with increasing amino acids concentrations both in water and aqueous surfactants solutions, which indicate strong intermolecular interactions in amino acids solutions. From results it is also obvious that due to the presence of resonance stabilization, aspartic acid interacts more strongly in both aqueous and SDS environment than serine.

The density, d, viscosity, η, and the conductance, Λ, values of solutions of l -phenylalanine in aqueous and aqueous solutions of d -glucose (5, 10, 15, and 20 wt%) have been determined at four different temperatures ranging from 298.15 K to 313.15 K at 5 K intervals. Sound velocity has been measured at 298.15 K. The experimental data were used to calculate apparent molar volume, Vφ, limiting apparent molar volume, Vφ°, apparent molar isentropic compressibility, Ks,φ, and limiting apparent molar isentropic compressibility, Ks,φ°. The derived acoustical and thermodynamics parameters, namely isentropic compressibility, Ks, specific acoustic impedance, Z, molar compressibility, W, molar sound velocity, R, free length, Lf, and relative association, RA, have been calculated. Shedlovsky equation has been used to obtain limiting molar conductance, Λm°, from the conductance data. The results have been discussed in terms of solute–solute, solute–solvent and solvent–solvent interactions.

Densities and Refractive Indices of solutions of potassium bromate (KBrO3) have been studied in water and 0.1%, 0.2%, 0.3%, 0.4% and 0.5% (w/v) aqueous solution of KCl with temperature in the range T = 298.15˚K- 313.15˚K. The data obtained is utilized to determine Specific Refraction (RD) and Molar Refraction (RM) of solutions. The values of Refractive indices, Molar Refraction (RM) and Molar Polarisability (α) constant are found to be decreased with decreasing concentration of solute in solvent and these results are also interpreted in terms of interaction in salt solution. It has been verified that Molar Refraction is additive and constitutive property.

The density, dynamic viscosity, and dielectric constant of propylene carbonate solutions with acetonitrile are measured over the composition of a mixed solvent at temperatures of 253.15, 273.15, 293.15, and 313.15 K. The molar volume, molar viscosity, and molar capacity of a mixture of propylene carbonate–acetonitrile and an excess amount of it are calculated. The effect the temperature and composition of the mixture have on the excess molar properties is discussed. A linear correlation is observed between the values of the molar fluidity, capacity, polarization, and molar volume of the studied system.

Density and speed of sound data for dilute aqueous solutions of four linear 2-alkoxyethanols, H–(CH2)n–O–CH2–CH2–OH, CnE1 for n = 1, 2, 3, 4, were measured using the Anton Paar DSA 5000 vibrating-tube densimeter and sound analyzer in the temperature range from 278.15 to 343.15 K and at atmospheric pressure. Standard molar volumes and standard molar isentropic compressions were evaluated from the measured data. Present data were compared with values available for selected linear aliphatic polyethers and poly(ethylene glycols) and structure–property relationships were analyzed. Apparent molar quantities of aqueous 2-butoxyethanol in wider concentration range were evaluated and effects of aggregation of the solute molecules were considered.

Experimental density values were obtained in 30 mixtures of the binary system water + 3-butoxypropan-1-amine at five temperatures T = (283.15 to 303.15) K and over the entire composition range. The temperature and composition effects on the different molar, apparent molar, excess molar, and partial molar properties derived from density were analyzed to comprehend the effect of hydrophobic/hydrophilic balance in the aggregation patterns and hydration schemes over the whole composition range. A comparison of the different thermodynamic properties, derived for this system, with those for the aqueous system of 3-ethoxypropan-1-amine with two fewer methylene groups is made.

In this work, experimental densities (ρ), speeds of sound (u) and relative viscosities (ηr) of DIL i.e. 1, 1-(propane-1, 3-diyl)-bis (3-methyl-1H-imidazolium-1-yl) dibromide or Bis C3 (mim) Br2 in aqueous solution 0.1 mol kg− 1 of d -glucose as a function of concentration have been measured at T/K = (293.15, 298.15, 303.15, 308.15 and 313.15). From these experimental data, thermodynamic and transport functions such as apparent molar volume (Vϕ) of solute, limiting apparent molar volume of solute (Vϕ0), isentropic compressibility(κs), apparent molar isentropic compressibility (κϕ) of solute, limiting apparent molar compressibility of solute (κϕ0), limiting apparent molar expansivity (Eϕ0) of solute, thermal expansion coefficient(α∗), Jones-Dole viscosity coefficientsA, Β, D variation of viscosity Βcoefficient with temperature i.e. dΒ/dT, hydration number of DIL in water and in aqueous solutions of d -glucose have been calculated. Transfer volumes Δ tr V ϕ 0 and transfer compressibilities Δ tr κ ϕ 0 of DIL from water to aqueous solutions of d -glucose at different temperatures have also been obtained. The results obtained have been interpreted in terms of various interactions taking place among solute and solvent molecules.

Volumetric and ultrasonic properties of ionic liquid (IL) with molecular solvents are important parameter for elucidation of solute-solute and solute-solvent interactions occurring in solutions. In the present work, the density, ρ and speed of sound, u for binary solutions of the protic ionic liquid (1,8-diazabicyclo [5.4.0] undec-7-en-8-ium trifluromethane sulfonate), with molecular solvents like water and ethanol have been measured as a function of molality in temperature range (293.15 to 318.15) K and at atmospheric pressure. From the experimental data, apparent molar volume, V φ , apparent molar isentropic compression, K s ,φ and limiting apparent molar expansion, E φ ∞ have been calculated. Further, to understand the extent of interaction between studied IL and solvents the apparent molar properties at infinite dilution were analyzed by using Redlich-Mayer type equation.