Values Of Molar Volume Research Articles

Investigations of volumetric, acoustic and optical properties of aqueous binary mixtures of different glycol ethers at temperatures 278.15 K and 288.15 K

The experimental data of densities (ρ), speeds of sound (u) and refractive indices (nD) of aqueous binary mixtures of different glycol ethers, namely, ethylene glycol monomethyl ether (EGMME), ethylene glycol monoethyl ether (EGMEE), diethylene glycol monomethyl ether (DEGMME) and diethylene glycol monoethyl ether (DEGMEE) over the entire composition range, at two different temperatures i.e. 278.15K and 288.15K and at one atmospheric pressure have been reported. Different derived parameters such as apparent molar volumes (∅V) of solute, excess molar volume (VE) of solution, isentropic compressibility (βS) of the solution, apparent molar isentropic compressibility (∅KS) of the solute have been computed. The limiting apparent molar volume of solutes (∅V0) and limiting apparent molar isentropic compressibility of solute (∅KS0) have been obtained for aqueous binary mixtures of these glycol ether by smooth extrapolation of ∅V–x2 and ∅KS–x2 curves to zero concentration, respectively. By using the values of ∅V0, the limiting excess partial molar volumes V¯20E have also been calculated. The values of excess molar volume (VE) of the solution were fitted in Redlich–Kister polynomial to obtain the coefficients of fitting equation. The results obtained in this study have been interpreted in terms of different interactions among solute and solvent molecules such as hydrogen bonding, solute–solute and solute–solvent interaction.

Study of Structure Making/Breaking Properties of Glucose, Fructose, Sucrose and Maltose in Aqueous KCl at Various Temperatures

The volumetric and viscometric studies of glucose, fructose, sucrose and maltose have been determined in 0.05 M and 0.5 M KCl solutions at 298.15, 303.15, 308.15 and 313.15 K. The apparent molar volume (φv) values vary linearly with square root of concentration of KCl solution. The limiting apparent molar volume (φ 0 v) has been interpreted in terms of solute-solvent interaction. The φ 0 v values vary with temperature and can be represented in the power series of structure making and breaking capacity of electrolyte is inferred from the sign of dB/dT values. The apparent molar expansibility has also been determined. Glucose, fructose, sucrose and maltose have been found to be structure maker and breaker in aqueous KCl from molar volume as well as viscosity studies.

Effect of 1-Ethyl-3-methylimidazolium Bromide Ionic Liquid on the Volumetric Behavior of Some Aqueous l-Amino Acids Solutions

Densities of aqueous solutions of glycine, l-alanine, l-arginine, and l-phenylalanine containing 1-ethyl-3-methylimidazolium bromide, [EMIm]Br, have been determined at T = (298.15 and 308.15) K. From the experimental density data, the apparent molar volumes (VΦ) and the standard partial molar volumes (VΦ0) at (298.15 and 308.15) K have been calculated. The values of standard partial molar volumes of transfer (ΔtrVΦ0) are also obtained and are negative for glycine, l-alanine, and l-phenylalanine while positive for l-arginine. The ΔtrVΦ0 values all increased with the increase of the temperature and also the [EMIm]Br content. The obtained volumetric parameters will be helpful to understand mixing effects and other complex biological processes between head and side chain groups of amino acids and ionic liquid [EMIm]Br in aqueous solution.

Densities, Viscosities and Speeds of sound for Binary Liquid Mixtures of Hexyl acetate with Some Aryl Compounds at Different Temperatures.

Densities and viscosities of binary mixtures of hexyl acetate with chlorobenzene, bromobenzene, fluorobenzene and nitrobenzene have been measured at (298.15, 303.15, 308.15 and 313.15) K over the entire composition range. Speeds of sound of these binary liquid mixtures have also been measured at 303.15 K. From the experimental density and viscosity data, the values of excess molar volume V E , free energy of activation for viscous flow Δ G E , while from the speed of sound data the isentropic compressibility K S , intermolecular free length L f , internal pressure π i , free volume V f , and specific acoustic impedance Z have been calculated. The excess molar volumes for these binary mixtures were negative over the whole composition range at all temperatures. The viscosity values were correlated using Frenkel and McAllister (four-body) models.

Volumetric, Compressibility and UV Spectral Studies on Interactions of Amino Acids with Aqueous Solutions of Potassium Dihydrogen Phosphate at Different Temperatures

Densities, ρ, and speeds of sound, u, for glycine, l-alanine and l-valine have been measured in (0.2, 0.4, 0.6 and 0.8) mol · kg−1 aqueous solutions of potassium dihydrogen phosphate at temperatures T = (288.15, 293.15, 298.15, 303.15, and 308.15) K. Values of the apparent molar volumes, limiting apparent molar volumes, and transfer volumes have been calculated from the density data. The experimental speeds of sound were used to estimate apparent molar adiabatic compressibilities. The variation of these parameters with temperature is discussed in terms of the role of amino acid and salt in solute–solvent interactions. The UV–visible spectrum has also been used to analyze the results.

Excess Molar Volumes and Excess Isentropic Compressibilities of o-Toluidine + Tetrahydropyran with Pyridine or Benzene or Toluene Ternary Mixtures at 298.15, 303.15 and 308.15 K

The densities, ρ123, and speeds of sound, u123, of ternary o-toluidine (OT, 1) + tetrahydropyran (THP, 2) + pyridine (Py) or benzene or toluene (3) mixtures have been measured as a function of composition at 298.15, 303.15 and 308.15 K. Values of the excess molar volumes, \( V_{123}^{\text{E}} , \) and excess isentropic compressibilities, \( (\kappa_{\text{S}}^{\text{E}} )_{123} , \) of the studied mixtures have been determined by employing the measured experimental data. The observed thermodynamic properties were fitted with the Redlich–Kister equation to determine adjustable ternary parameters and standard deviations. The \( V_{123}^{\text{E}} \) and \( (\kappa_{\text{S}}^{\text{E}} )_{123} \) values were also analyzed in terms of Graph theory. It was observed that Graph theory correctly predicts the sign as well as magnitude of \( V_{123}^{\text{E}} \) and \( (\kappa_{\text{S}}^{\text{E}} )_{123} \) values of the investigated mixtures. Analysis of the data suggests strong interactions and a more close packed arrangement in OT (1) + THP (2) + Py (3) mixtures as compared to those of the OT (1) + THP (2) + benzene (3) or toluene (3) mixtures. This may be due to the presence of a nitrogen atom in Py which results in stronger interactions for the OT:THP molecular entity as compared to those with benzene or toluene.

Effect of temperature on volumetric and transport properties of ternary poly ethylene glycol di-methyl ether 2000 + poly ethylene glycol 400 + water and the corresponding binary aqueous solutions: Measurement and correlation

The density, speed of sound and viscosity values of {poly ethylene glycol di-methyl ether 2000 (PEGDME2000)+poly ethylene glycol 400 (PEG400)+water}, ((PEGDME2000)+water) and ((PEG400)+water) solutions have been measured at T=(293.15, 298.15, 303.15, 308.15, and 313.15)K. From these measurements, values of the excess molar volume (VmE), excess molar isentropic compression (Ks,mE), excess Gibbs free energy of activation of viscous flow (G*E) and deviation of viscosity (Δη) were calculated. Expressions for VmE and Ks,mE of polymer solutions were obtained by the modified Wilson model for binary and multi-component polymer solutions. The necessary expression for Ks,mE of the polymer NRTL model was also obtained for multi-component polymer solutions. These expressions were used to fit the experimental VmE and Ks,mE data of the investigated systems. Furthermore, the Eyring-modified Wilson and Eyring-NRTL models have been used to correlate the viscosity values of binary and ternary solutions. The apparent specific volumes at infinite dilution values for the binary and ternary solutions were also determined from the density data at dilute range. These values were used to obtain some information regarding the segment–solvent and segment–segment interactions.

Volumetric, Acoustic, and Refractometric Study of Cyclic Alanylalanine in Aqueous Cobalt Chloride Solutions at Temperatures T = (293.15 to 313.15) K

Density, refractive index, and speed of sound values of cyclic alanylalanine + aqueous CoCl2 systems have been reported as a function of concentrations of cyclic alanylalanine and that of CoCl2 at temperatures T = (293.15, 298.15, 303.15, 308.15, and 313.15) K. The values of partial molar volumes, isentropic compressibilities, and partial molar isentropic compressibilities of the cyclic alanylalanine + aqueous CoCl2 systems have been calculated from the speed of sound and density data obtained from the experiment at various temperatures. The decreasing value of isentropic compressibility with respect to the molal concentration of cyclic alanylalanine and temperature indicated the presence of strong solute–solvent interaction operative in the present system. The variations in partial molar volumes as well as partial molar isentropic compressibilities have been discussed in terms of ionic, hydrophilic, and hydrophobic interactions present in the system.

Study of thermodynamic properties of aqueous binary mixtures of l-threonine, l-valine and l-arginine at low temperatures (T/K = 275.15, 279.15 and 283.15)

The experimental values of density (ρ) and speed of sound (u) in aqueous solutions of l-threonine, l-valine and l-arginine are reported at T=(275.15, 279.15 and 283.15)K. The derived parameters, apparent molar volume of solute (Vϕ), isentropic compressibility (kS) of solution, apparent molar compressibility of solute (kϕ) in dilute aqueous solutions of l-threonine, l-valine and l-arginine have been computed using values of density (ρ) and speed of sound (u). The limiting values of apparent molar volume of solute (Vϕ0), apparent molar isentropic compressibility of solute (kϕ0) and apparent molar expansivity (ϕE0) are also obtained. The results are discussed in the light of solute-solvent interactions, and structure making and structure breaking abilities of the solute in aqueous medium. From the results obtained for dϕE0/dT, it has been observed that l-threonine behaves as a structure maker, whereas l-valine and l-arginine act as structure breakers when dissolved in water at temperatures studied in present work.

Volume effects for binary mixtures of propane-1,2-diol with methanol, propan-1-ol, hexan-1-ol, octan-1-ol, or nonan-1-ol at temperatures (293.15 to 318.15) K

Values of the density for binary mixtures of propane-1,2-diol with methanol, propan-1-ol, hexan-1-ol, octan-1-ol, or nonan-1-ol were measured over the entire composition range and within the temperature range from (293.15 to 318.15)K by means of a vibrating tube densimeter. The excess molar volumes and limiting excess partial molar volumes were calculated. The Redlich–Kister polynomials were fitted to the results and smooth representations of the results are presented. The negative values of the excess molar volumes over the entire composition and temperature ranges are observed in the case of methanol and propan-1-ol. In the cases of hexan-1-ol, octan-1-ol, and nonan-1-ol, positive values of the excess molar volumes over the entire composition and temperature ranges are observed. The effect of temperature is discussed qualitatively.

Volumetric studies of aqueous solutions of monosodium salts of some aliphatic dicarboxylic acids at 298.15 K. A new method of data analysis

The apparent molar volumes, Vϕ, of monosodium salts of aliphatic dicarboxylic acids of the HOOC(CH2)n(COOH)2 [n=0–5] types in dilute aqueous solution have been determined by precise density measurements, at T=298.15K. Densities were measured using a vibrating-tube densimeter (DMA 5000, Anton Paar, Austria) at T=298.15K. These results were used to calculate the apparent molar volumes of each solute over the concentration range 0.0050≤m/(mol·kg−1)≤0.3000. A new method for determining the values of partial molar volume of the electrolyte of NaHA type has been proposed. This method takes into account all equilibrium occurring in the solution. The variations of Vϕ0 values with aliphatic chain length of analyzed salts were determined.

Acoustic and thermodynamic properties of binary mixtures of 1-nonanol with o-xylene, m-xylene, p-xylene, ethylbenzene and mesitylene at T = (298.15 and 308.15) K

Densities, ρ, and speeds of sound, u, of binary liquid mixtures of 1-nonanol with o-xylene, m-xylene, p-xylene, ethylbenzene and mesitylene have been measured over the entire range of composition at T=(298.15 and 308.15)K and at atmospheric pressure. Using these results, the values of the excess molar volume, VE, isentropic compressibility, κS, molar isentropic compressibility, KS,m, excess molar isentropic compressibility, KS,mE, deviations of the speed of sound, uD, and excess partial molar volume, V¯m,iE,0, and excess partial molar isentropic compressibility, K¯m,iE,0 at infinite dilution, have been calculated. The calculated excess and deviation functions have been fitted to the Redlich–Kister polynomial equations and the results analysed in terms of molecular interactions.

Thermal stability and thermal property characterisation of Fe–14.4Cr–15.4Ni–2.4Mo–2.36Mn–0.25Ti–1.02Si–0.042C–0.04P–0.005B (mass%) austenitic stainless steel (Alloy D9I)

High temperature measurements of enthalpy increment (ΔHT°) and lattice parameter have been carried out on Alloy D9I by means of drop calorimetry and high temperature X-ray diffraction techniques, respectively. In addition, the thermal stability during heating and cooling from the melting range has been investigated by differential scanning calorimetry. It is found that under near equilibrium cooling conditions (3Kmin−1), Alloy D9I exhibits L→γ austenite→L+γ+δ ferrite→γ+δ→γ solidification mode. However, the phase fraction of δ ferrite and the temperature region of γ+δ two phase domain are found to be small. The on-cooling liquidus and solidus temperatures are found to be 1684 and 1631±5K, respectively. The latent heat of solidification is found to be in the range, 190–220Jg−1. The thermal analysis study has revealed that solution treated Alloy D9I exhibits an endothermic dissolution of Ti(C,N) particles at about 1323±2K, with an associated heat effect of 16–20Jg−1. The specific heat Cp and coefficient of linear thermal expansion αl at 298.15K are estimated to be 486Jkg−1K−1 and 1.15×10−5K−1, respectively. The measured temperature dependencies of Cp and αl for Alloy D9I are in good agreement with the general trend exhibited by many austenitic steels. Further, an empirical linear correlation has been found between the measured temperature dependent molar volume and molar enthalpy values. The measured thermal property data have been modelled through Debye–Grüneisen formalism to obtain an integrated and self-consistent estimate of thermal properties in a comprehensive temperature domain ranging from 0 to 1400K.

Density, Viscosity, and Conductivity of Lewis Acidic 1-Butyl- and 1-Hydrogen-3-methylimidazolium Chloroaluminate Ionic Liquids

To promote the development of Lewis acidic chloroaluminate ionic liquids, it is necessary to get a deeper insight into their physicochemical properties and molecular structure. In this work, the densities, viscosities, and conductivities of acidic 1-butyl- and 1-hydrogen-3-methylimidazolium chloroaluminate with different mole fractions of AlCl3 were measured in the temperature range from (293.15 to 343.15) K. Meanwhile, excess molar volume and viscosity deviation values for the binary mixtures of 1-butyl-3-methylimidazolium chloroaluminate ionic liquids were also obtained. All of the experimental data were well-fitted by the empirical equations. Based on the results of density functional theory calculations, the differences in these properties are attributed to the molecular structure, cation–anion interaction, and hydrogen bonds of ionic liquids. It is expected that the present study may be deemed useful for the application of Lewis acidic chloroaluminate ionic liquids in electrochemistry and catalysis.

Density, speed of sound, viscosity and refractive index properties of aqueous solutions of vitamins B1.HCl and B6.HCl at temperatures (278.15, 288.15, and 298.15) K

The experimental values of density (ρ), speed of sound (u), absolute viscosity (η) and refractive index (nD) properties are reported for aqueous solutions of thiamine hydrochloride (vitamin B1.HCl) and pyridoxine hydrochloride (vitamin B6.HCl) within the concentration range (0.01 to 0.55)mol⋅kg−1 at three different temperatures, viz. T/K=278.15, 288.15, and 298.15. Using experimental data, different derived parameters such as the apparent molar volume of solute (ϕV), isentropic compressibility of solution (βS), apparent molar isentropic compressibility of solute (ϕKS) and relative viscosity of solution (ηr) have been computed. The limiting values of apparent molar volume (ϕV0) and apparent molar isentropic compressibility (ϕKS0) have been obtained. The limiting apparent molar expansivity (ϕE0) of solute, coefficient of thermal expansion (α∗) and hydration numbers (nh) of above vitamins in the aqueous medium have also been estimated. The experimental values of relative viscosity are used to calculate the Jones–Dole equation viscosity A and B coefficients for the hydrochlorides. The temperature coefficients of B i.e. (dB/dT) for these solutes have been used to study water structure making and breaking effects due to cations. Further, a discussion is made on the basis of solute–solute and solute–solvent interactions.

A comparative study of the volumetric properties of aqueous solutions of pyridine and piperidine derivatives

The objective of this research was to carry out a comparative study of the volumetric properties of 2-pyridinemethanol, 3-pyridinemethanol, 2-(hydroxymethyl)piperidine, and 3-(hydroxymethyl)piperidine in aqueous media. The density and excess volumes of mixing as a function of temperature (T=293.15–318.15K) over the entire concentration range are examined for aqueous solutions of 2,3-pyridinemethanols, and the density and partial molar volumes of aqueous solutions are investigated for the corresponding 2,3-(hydroxymethyl)piperidines. The minimum values of the excess molar volumes, vE, are observed, −0.59cm3mol−1 for 2-pyridinemethanol–water solutions and −0.47 for 3-pyridinemethanol–water solutions. These are about 0.61% and 0.49% respectively, of the molar volume. The thermal expansion coefficients αT at 298.15K calculated from the density data, exhibited significant positive deviations, (about 30%) from ideality for 2-pyridinemethanol–water mixtures, and 3-pyridinemethanol–water mixtures. The partial molar volume of 2,3-(hydroxymethyl)piperidines in water at selected temperatures was evaluated by extrapolating the apparent molar volume versus molality plots to m=0. In addition, the partial molar expansivity, E0, the isobaric coefficient of thermal expansion, αT, the interaction coefficient, Sv, and the Hepler's constant have also been computed. The data are interpreted in terms of the effect of the primary alcohol functional group on the inter/intramolecular and additional hydrophilic interactions between the molecules.

Liquid phase PVTx properties of (water + tert-butanol) binary mixtures at temperatures from 278.15 to 323.15 K and pressures from 0.1 to 100 MPa: I. Experimental results, excess and partial molar volumes

The coefficient of compressibility, k=ΔV/Vo, of {water (1)+tert-butanol (2)} binary mixture was measured at pressures from 0.1 to 100MPa and temperatures from 278.15 to 323.15K over the concentration range of liquid mixture occurrence. The whole composition range from 0 to 1 tert-butanol mole fraction was studied at 323.15K only because of the mixture freezing at lower temperatures. Over the whole pressure range in question partial molar volumes of the components at all temperatures studied and excess molar volumes of the mixture only at 323.15K were calculated. It was shown that when pressure increased, the values of excess molar volume decreased, and minimum on concentration dependence of VE on tert-butanol mole fraction shifted to the region of low tert-butanol content. For every pressure studied extremes were observed on the concentration dependences of partial molar volumes of the mixture components. The values of limiting partial molar volumes increased with temperature growth and tended to maximum at pressure slightly higher of 100MPa.

Excess Molar Volumes, Excess Molar Enthalpies, and Excess Isentropic Compressibilities of Binary Mixtures Containing N-Methyl-2-Pyrrolidone and Isomeric Xylenes at 308.15 K

Excess molar volumes, excess molar enthalpies and speeds of sound of 1-methyl pyrrolidin-2-one + o- or m- or p-xylene binary mixtures have been measured over the entire composition range at 308.15 K. The speed of sound data were used to determine the excess isentropic compressibilities. It is observed that while the values of the excess molar enthalpies for the investigated mixtures are positive, the values of the excess molar volumes and excess isentropic compressibilities are negative over the entire composition range. The measured thermodynamic data have been analyzed in terms of Graph, Prigogine–Flory–Patterson, and the Sanchez and Lacombe theories. It is observed that Graph theory correctly predicts the signs and magnitudes of the excess molar volumes, excess molar enthalpies, and excess isentropic compressibilities of the studied mixtures. However, the excess molar volumes, excess molar enthalpies and excess isentropic compressibilities predicted by Prigogine–Flory–Patterson and Sanchez and Lacombe theories are of same sign.

Studies on solution properties of ternary mixture of acetophenone + n-amyl alcohol + dichloromethane and its corresponding binaries at 298.15 K

The excess values of molar volume (V E), viscosity deviation (Δη), deviation in isentropic compressibility (ΔKS ), excess molar refraction (ΔR) and excess Gibbs energy of activation (ΔG*E ) of viscous flow have been investigated from the experimentally measured densities, viscosities, sound speeds and refractive indices for three binary mixtures of acetophenone + n-amyl alcohol, acetophenone + dichloromethane and n-amyl alcohol + dichloromethane and their corresponding ternary mixtures at 298.15 K over the entire composition range. The calculated quantities are further fitted to the Redlich–Kister equation to estimate the binary fitting parameters and standard deviations from the regression lines. The excess or deviation properties were found to be either negative or positive depending on the molecular interactions and the nature of liquid mixtures and have been discussed in terms of molecular interactions and structural changes.

Solvent Effect on the Enthalpy of Solution and Partial Molar Volume of the Ionic Liquid 1-Butyl-3-methylimidazolium Tetrafluoroborate

Enthalpies of solution and partial molar volumes of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate were determined in 15 solvents of different polarity. Very large differences of the enthalpies of solution (ΔΔsolHIL=38.9 kJ⋅mol−1) and partial molar volumes (ΔVIL=43 cm3⋅mol−1) are nearly the same as observed for lithium perchlorate solutions. These results clearly indicate that the low values of the macroscopic polarity parameters of [bmim]BF4 do not correspond with the large differences of the intermolecular interactions in IL solutions. The values of the partial molar volume of the cation, \(V_{[\mathrm{bmim}]^{+}}\), were estimated for the first time. The changes of the partial molar volumes, VIL, reflect mainly the changes of anion volume, \(V_{\mathrm{BF}_{4}^{-}}\). The rate of the Diels–Alder reaction of 9,10-dimethylanthracene with maleic anhydride in the [bmim]BF4 medium was nearly the same as in common molecular solvents.