Partial Molar Expansibilities Research Articles

Phenomenon of “negative partial molar expansibility” of water in tetrahydrofuran: How plausible is it?: Discussion on the paper “Volumetric properties on the (tetrahydrofuran + water) and (tetra- n-butylammonium bromide + water) systems: Experimental measurements and correlations” by Veronica Belandria, Ammir H. Mohammadi and Dominique Richon [J. Chem. Thermodyn. 41 (2009) 1382−1386

In order to answer the question: is a solute water “negatively expansible” in tetrahydrofuran or not (?), a comparative analysis of own and literature data on the temperature-dependent partial volumes at the infinite dilution of water isotopologues in tetrahydrofuran have been carried out. Used for computing the limiting partial (apparent) volumes of water isotopologues, densities of H 2O and D 2O solutions in the solvent studied, with the solute mole fractions ranging up to ∼0.043, were measured with an error of 1.5 · 10 −5 cm 3 · mol −1 at (278.15, 288.15, 298.15, 308.15, and 318.15) K and atmospheric pressure using a vibrating tube densimeter. It has been shown that the partial molar volume of H 2O or D 2O at infinite dilution increases with rising temperature; that is, the isotopically distinguishable solutions of water in tetrahydrofuran do not have the unusual structure-packing behavior being characteristic of the water-containing system with the so-called phenomenon of “negative partial molar expansibility”.

Effect of magnesium chloride (2:1 electrolyte) on the aqueous solution behavior of some saccharides over the temperature range of 288.15–318.15 K: a volumetric approach

Infinite-dilution standard partial molar volumes, V 2 0 , for various mono-, di-, and trisaccharides, and their derivatives (methyl glycosides) at molalities ranging from 0.04 to 0.12 mol kg −1 in aqueous solutions of magnesium chloride of 0.5, 1.0, 2.0, and 3.0 mol kg −1, have been evaluated over a range of temperatures from 288.15 to 318.15 K by density measurements employing a vibrating-tube densimeter. These data have been utilized to determine the corresponding standard partial molar volumes of transfer, Δ t V 2 0 , of saccharides and methyl glycosides from water to aqueous magnesium chloride solutions. The Δ t V 2 0 values have been found to be positive, and their magnitudes increase with an increasing concentration of magnesium chloride in all cases. Partial molar expansion coefficients, ( ∂ V 2 0 / ∂ T ) P and second derivatives thereof, ( ∂ 2 V 2 0 / ∂ T 2 ) P have been estimated. The magnitude of V 2 0 values increases with an increase in temperature, indicating that hydration effects in solutions are strongly sensitive to temperature. Pair and higher order volumetric interaction coefficients ( V AB, V ABB) have also been obtained from Δ t V 2 0 values by using the McMillan–Mayer theory. The various parameters have been discussed in terms of the solute (saccharide or methyl glycoside)–co-solute (magnesium chloride) interactions and are thus used to understand the mixing effects due to these interactions. These results have been compared with those earlier reported in the presence of electrolytes. An attempt is made to interpret the volumetric properties data in terms of the stereochemistry of the solutes.

Effect of Temperature on the Interactions of Glycyl Dipeptides with Sodium Dodecyl Sulfate in Aqueous Solution: A Volumetric, Conductometric, and Fluorescence Probe Study

The interactions of glycyl dipeptides (2-[(2-aminoacetyl)amino]acetic acid (commonly known as glycylglycine), 2-[(2-aminoacetyl)amino]-3-methylbutanoic acid (commonly known as glycyl-l-valine), and (2S)-2-[(2-aminoacetyl)amino]-4-methylpentanoic acid (commonly known as glycyl-l-leucine)) with sodium dodecyl sulfate (SDS) as a function of temperature in aqueous solution have been investigated by a combination of density, conductivity, and fluorescence methods. The standard partial molar volume (V2,ϕo), standard partial molar volumes of transfer for dipeptide from water to aqueous SDS solutions (ΔtVo), partial molar expansibility (Eϕo), and Hepler’s constant have been calculated from density data. Electrical conductivity was used to estimate the critical micellar concentration (cmc) and the thermodynamic parameters of micellization of SDS in aqueous peptide solutions. The change of micropolarity produced by the interaction was monitored by the measurement of emission intensity ratio between the first and th...

Ultrasound Speeds and Molar Isentropic Compressions of Aqueous 2-(Ethylamino)ethanol Mixtures from 283.15 to 303.15 K

Ultrasound speeds in 31 aqueous binary mixtures of 2-(ethylamino)ethanol (EEA) were experimentally determined over the entire composition range at 283.15, 288.15 and 303.15 K. Isentropic compressibilities, κS, were calculated by combining the ultrasound speed with density data. Excess molar isentropic compressions, \(K_{S,\mathrm{m}}^{\mathrm{E}}\), referred to a thermodynamically-defined ideal liquid mixture, were estimated. Excess partial molar isentropic compressions, \(K_{S,i}^{\mathrm{E}}\), of both components and their respective limits at infinite dilution, \(K_{S,i}^{\mathrm{E,}\infty}\), were analytically obtained using Redlich-Kister type equations. The temperature and composition dependences of \(K_{S,i}^{\mathrm{E}}\) were analyzed, especially in the water and EEA rich regions. The present \(K_{S,i}^{\mathrm{E,}\infty}\) values are compared with those for water + 2-diethylaminoethanol (DEEA) and water + diethylamine (DEA) mixtures, as a function of temperature. Although the \(K_{S,2}^{\mathrm{E,}\infty}\) values for EEA and DEEA increase with temperature, the opposite trend is observed for DEA. Results for aqueous EEA and aqueous DEEA seem to support the idea that the driving force for hydrophobic hydration relies on solute-solvent hydrophilic interaction rather than on enhancing the water structure. On the other hand, different temperature dependent behavior is observed for the differential volumetric properties \(K_{S,i}^{\mathrm{E,}\infty}\) and limiting excess partial molar isobaric expansion, \(E_{P,i}^{\mathrm{E,}\infty}\), which are attributed to the different sensitivity of these properties to hydration.

Investigation on molecular interactions of nicotinamide in aqueous citric acid monohydrate solutions with reference to manifestation of partial molar volume and viscosity B-coefficient measurements

Apparent molar volumes ( V ϕ), viscosity B-coefficients for nicotinamide in 0.03, 0.05, 0.07 and 0.10 mol dm −3 aqueous citric acid monohydrate solutions have been determined from solution density and viscosity measurements at 298.15, 308.15 and 318.15 K as function of concentration of nicotinamide. The apparent molar volumes have been extrapolated to zero concentration to obtain the limiting values at infinite dilution using Masson equation. The infinite dilution partial molar expansibilities have also been calculated from the temperature dependence of the limiting apparent molar volumes. This results have, in conjunction with the results obtained in pure water, been used to calculate the standard volumes of transfer Δ V ϕ 0 and viscosity B-coefficients of transfer for nicotinamide from water to aqueous citric acid monohydrate solutions for rationalizing various interactions in the ternary solutions. The structure making or breaking ability of nicotinamide has been discussed in terms of the sign of ∂ 2 V ϕ 0 / ∂ T 2 p and dB/ dT. An increase in the transfer volume of nicotinamide with increasing citric acid monohydrate concentration has been explained by Friedman–Krishnan co-sphere model. The activation parameters of viscous flow for the ternary solutions studied have also been calculated and explained by the application of transition state theory.

Volumetric, Refractometric, and Excess Properties of Glycylglycine in Aqueous FeCl2 Solution at Temperatures T = (288.15 to 318.15) K

Densities and refractive indices have been measured for glycylglycine in aqueous FeCl2 solution as a function of concentration at T = (288.15 to 318.15) K. The apparent molar volumes and partial molar volumes were obtained from these density data. The limited partial molar expansivities have been calculated from the temperature dependence of the partial molar volume. The molar refractions were calculated from the experimental refractive index values for the studied mixture. The excess volumes and molar refractions were also calculated. The results are discussed in terms of molecular interactions.

Temperature dependence of the excess molar volume of 1-hexanol + 1-alkene systems in terms of an association and equation of state model

Excess molar volumes V E measured at 288.15 and 308.15 K for (1-hexanol + 1-hexene), (1-hexanol + 1-octene) and (1-hexanol + 1-decene) systems are reported. The data and the measurements reported before at 298.15 K for this series of mixtures were used to estimate the excess molar isobaric thermal expansion A p E = ( ∂ V E / ∂ T ) p and the partial molar excess isobaric thermal expansions A p , i E of the components at 298.15 K. The A p E as a function of concentration, changes from positive–negative for the systems formed by short-chain 1-alkenes like 1-hexene to positive for 1-decene over the whole concentration range. The modified Treszczanowicz and Benson model (TB) is applied to interpret and to predict changes in the size and shape of the A p E and A p , i E curves. The model predicts qualitatively well the changes of the A p E and A p , i E values in the series of mixtures as a superposition of the contributions due to self-association of alkanol, free volume, OH⋯π interactions and residual van der Waals interactions. These contributions to the properties investigated are estimated and discussed in the series of mixtures. The results obtained are compared with those for 1-alkanol + n-alkane systems.

Volumetric and viscometric studies of glucose in binary aqueous solutions of urea at different temperatures

Densities and viscosities of glucose in (1.0, 2.5, and 5.0) mass% aqueous urea solutions have been measured at T = (298.15, 303.15, 308.15, and 313.15) K, respectively. Apparent molar volumes, limiting partial molar volume, and relative viscosity have been obtained from the density and viscosity results. Limiting partial molar expansibilities have also been calculated from the temperature dependence of limiting partial molar volumes. The viscosity data have been analyzed by using the modified Jones–Dole equation. The results are used to establish the nature of solute–solute and solute–solvent interactions. Transition state treatment of the relative viscosity was also used for the calculation of activation parameters of viscous flow. Pour findings show that the solute acts as a water structure former and provides strong solute–solvent interaction.

Effect of temperature on volumetric and viscometric properties of some non-steroidal anti-inflammatory drugs in aprotic solvents

Densities and viscosities of salicyl amide, salicylic acid, and acetyl salicylic acid (non-steroidal anti-inflammatory drugs) in two aprotic solvents namely, dimethyl sulfoxide and acetonitrile at T = (293.15, 298.15, 303.15, 308.15, 310.15, and 313.15) K have been determined in a molality range of (9.7 · 10 −3 to 33.3 · 10 −3) mol · kg −1. The data have been used to calculate apparent molar volumes ( V ϕ ,), and viscosity B-coefficients. The partial molar volumes and hydration numbers have been determined at different temperatures. The effect of temperature on the thermodynamic properties has been studied by determining partial molar expansibilities ∂ V m 0 / ∂ T and Hepler’s constant ∂ 2 V m 0 / ∂ T 2 . Free energies of activation for viscous flow of the solution were obtained by application of the transition state theory of solutions to the B-coefficient data and the corresponding activation enthalpies are reported.

Volumetric and Viscometric Properties of Some Sulpha Drugs in Aqueous Solutions of Sodium Chloride at T = (288.15 to 318.15) K

The partial molar volumes V2° and viscosity B-coefficient have been measured from density and flow time measurements for sulphanilamide, sulphanilic acid, and sulphosalicylic acid dihydrate in water and in aqueous solutions of (0.05, 0.1, 0.3, and 0.5) mol·kg−1 sodium chloride at temperatures from (288.15 to 318.15) K, by the use of a vibrating tube digital densimeter and Micro-Ubbelohde type capillary viscometer, respectively. The transfer volumes at infinite dilution calculated from partial molar volumes have both positive and negative values. The overall positive values at higher concentrations of sodium chloride are in the following order: sulphosalicylic acid dihydrate > sulphanilic acid > sulphanilamide, which is also the order of hydrophilicity of these drugs. The interaction coefficients, partial molar expansibilities VE°, and second-order derivative have also been calculated. The transfer B-coefficient values, ΔtrB, are calculated from viscosity B-coefficient data. Transition state theory has bee...

Thermodynamic Properties of Inorganic Salts in Nonaqueous Solvents. VI. Apparent Molar Volumes, Expansibilities, and Compressibilities of Divalent Transition Metal Ions in Methanol and Dimethylsulfoxide

The temperature dependence of the density of divalent transition metal perchlorates in dimethylsulfoxide as well as cobalt(II), nickel(II) perchlorates, and copper(II) trifluoromethanesulfonate in methanol was determined. Moreover, sound velocities for solutions of cobalt(II), nickel(II) perchlorates, and copper(II) trifluoromethanesulfonate in methanol have been measured at 298.15 K. From these data, the partial molar volumes, partial molar expansibilities, and partial molar isentropic compressibilities have been estimated. The results obtained are discussed in terms of ion−solvent interactions.

Studies on the Solute Solvent Interaction of Nimesulide in Aqueous Solutions of Hydrotropic Agents at Different Temperatures

The present study deals with experiments so as to highlight the solute (drug nimesulide) ‐ solvent(water) interactions and related modifications in case of the presence of hydrotropic agents at different temperatures T(=298.15 to 313.15)K. Density and viscosity values of nimesulide have been determined in water in (0.1, 0.2, 0.4, 0.6, 0.8, 1 and 2) mol dm-3 aqueous solutions of hydrotropic agents (sodium benzoate, sodium salicylate, sodium bromide and nicotinamide) at temperatures 298.15, 303.15, 308.15 and 313.15 K where as the solubility was studied at 308.15 K. From the density values, the limiting partial molar volumes and expansibilities have been calculated. The experimental viscosity values have been analyzed in terms of jones‐dole equation and on the basis of transition theory for relative viscosity.

Solute–solvent and solvent–solvent interactions of menthol in isopropyl alcohol and its binary mixtures with methyl salicylate by volumetric, viscometric, interferometric and refractive index techniques

The apparent molar volume ( V ∅ ), viscosity B-coefficient, isoentropic compressibility ( ϕ K ) of menthol have been determined in binary solution of isopropyl alcohol and methyl salicylate (at 303.15, 313.15 and 323.15 K) from density ( ρ), viscosity ( η) and sound speed respectively. The apparent molar volumes have been extrapolated to zero concentration to obtain the limiting values at infinite dilution using Masson equation. The infinite dilution partial molar expansibilities have also been calculated from the temperature dependence of the limiting apparent molar volumes. Viscosity B-coefficients has been calculated using Jones–Dole equation. The structure-making or breaking capacity of the solute under investigation has been discussed in terms of sign of ( δ 2 V Ø o / δ T 2 ) P . The activation parameters of viscous flow were determined and discussed by application of transition state theory.

Volumetric Properties of Aqueous Solutions of Tetramethyl-bis-urea between 278.15 and 338.15 K at Atmospheric Pressure

Densities of aqueous solutions of tetramethyl-bis-urea (TMbU) with solute mole fractions ranging up to 7.0×10−2 have been measured with an uncertainty of 1.5×10−5 g⋅cm−3, at 278.15, 298.15, 318.15, and 338.15 K using a vibrating-tube densimeter. The partial molar volumes and expansibilities of TMbU (down to the infinite dilution) and water have been computed. The effects of solute concentration and temperature on the volume packing changes, caused by dissolution (and hydration) of TMbU in an aqueous medium, have been considered.

Volumetric and viscometric studies of urea in binary aqueous solutions of glucose at different temperatures

Densities and viscosities of urea in (1.0, 2.5, and 5.0) mass% of aqueous glucose solutions have been measured at T = (298.15, 303.15, 308.15, and 313.15) K, respectively. Apparent molar volumes, limiting partial molar volume, and relative viscosity have been obtained from the density and viscosity data. Limiting partial molar expansibilities have also been calculated from the temperature dependence of limiting partial molar volumes. The viscosity data has been analyzed using the Jones–Dole equation. The results are used to establish the nature of solute–solute and solute–solvent interactions. The activation parameters of viscous flow have also been calculated on the basis of transition state treatment of the relative viscosity. Result shows that the solute acts as water structure breaker and posses’ weak solute–solvent interaction.

The Partial Molar Heat Capacities and Expansions of Inosine, 2′-Deoxyinosine and 2′-Deoxyguanosine in Aqueous Solution at 298.15 K

Solution densities over the temperature range 288.15 to 313.15 K have been measured for aqueous solutions of the nucleosides inosine, 2′-deoxyinosine, and 2′-deoxyguanosine, from which the partial molar volumes of the solutes at infinite dilution, V 2 o , were obtained. The partial molar expansions for the nucleosides at infinite dilution and 298.15 K, E 2 o {E 2 o =(∂ V 2 o /∂ T) p }, were derived from the V 2 o results. The V 2 o values at 298.15 K for the two sugars D-ribose and 2-deoxyribose also have been determined. The partial molar heat capacities at infinite dilution for all the solutes, C p,2 o , have been determined at 298.15 K. These V 2 o ,E 2 o , and C p,2 o results are critically compared with all of the results available from the literature, and the use of group additivity to evaluate these solution thermodynamic properties for the sparingly soluble nucleoside guanosine is explored.

Thermodynamic properties of peptide solutions 19. Partial molar isothermal compressions at T = 298.15 K of some peptides of sequence gly-X-gly in aqueous solution

The partial molar isobaric expansions at infinite dilution and T = 298.15 K, E 2 ∘ { E 2 ∘ = ( ∂ V 2 ∘ / ∂ T ) p } were determined recently for some tripeptides of sequence glycyl-X-glycine, where X is one of the amino acids alanine, valine, leucine, isoleucine, phenylalanine, methionine, proline, serine, threonine, asparagine, glutamine, histidine, and tyrosine. These quantities, along with partial molar heat capacity data available from the literature, were used to convert the partial molar isentropic compressions at infinite dilution determined previously for these tripeptides into the partial molar isothermal compressions at infinite dilution and T = 298.15 K, K T , 2 ∘ { K T , 2 ∘ = - ( ∂ V 2 ∘ / ∂ p ) T } . These K T , 2 ∘ results, along with that for triglycine, were used to estimate the contributions of the amino acid side-chains to the partial molar isothermal compressions of peptides. The side-chain contributions have been rationalized in terms of the likely peptide–water interactions.

Volumetric Studies of Sodium Chloride in Aqueous and Aqueous Maltose Systems at Different Temperatures

Densities of sodium chloride in the concentration range (0.010 to 0.090 ± 0.001) mol·dm−3 have been determined in aqueous and aqueous maltose systems [(1.0, 3.0, 5.0, and 7.0) % w/v] at different temperatures [(298 to 323) K] with the interval of 5 K. Apparent molar volume (ϕν), partial molar volume (ϕν°) and the ion−ion interaction parameter (Sv) have been calculated, using the Masson equation by applying linear regression analysis. Other parameters were also calculated, viz., transfer volume (ϕν°(tr)) and partial molar expansibility (ϕE°). Values of ϕE° show the presence of caging or packing effects. The data obtained from volumetric studies have been used to investigate the ion−solvent interaction and ion−ion interaction. The structure-breaking capacity of sodium chloride has been inferred in aqueous and aqueous maltose systems from Hepler’s criterion, i.e., (∂2ϕν°/∂Τ2)Ρ second derivative of partial molar volume with respect to temperature at constant pressure.

Effect of sodium acetate on the volumetric behaviour of some mono-, di-, and tri-saccharides in aqueous solutions over temperature range (288.15 to 318.15) K

The standard partial molar volumes, V 2 ∘ at infinite dilution of eight monosaccharides [ d(+)-xylose, d(−)-arabinose, d(−)-ribose, l(−)-sorbose, d(−)-fructose, d(+)-galactose, d(+)-glucose, and d(+)-mannose], six disaccharides [ d(+)-cellobiose, sucrose, d(+)-melibiose, d(+)-lactose monohydrate, d(+)-trehalose dihydrate, and d(+)-maltose monohydrate] and two trisaccharides [ d(+)-melizitose and d(+)-raffinose pentahydrate] (molalities of saccharides range from (0.03 to 0.12) mol · kg −1) have been determined in water and in (0.5, 1.0, 2.0, and 3.0) mol · kg −1 aqueous sodium acetate solutions at temperatures, T = (288.15, 298.15, 308.15, and 318.15) K from density measurements using a vibrating-tube digital densimeter. From these results, corresponding standard partial molar volumes of transfer, Δ t V 2 ∘ have been determined for the transfer of various saccharides from water to aqueous solutions of sodium acetate. Positive values of Δ t V 2 ∘ were obtained for most of the saccharides, whose magnitude increase with the concentration of sodium acetate as well as temperature. However, negative Δ t V 2 ∘ values were observed for l(−)-sorbose, d(−)-fructose and d(+)-xylose at lower concentrations of co-solute. The negative magnitude of Δ t V 2 ∘ values decrease with rise of temperature from (288.15 to 318.15) K. Pair and higher order volumetric interaction coefficients have been determined by using McMillan–Mayer theory. Partial molar expansion coefficients, ( ∂ V 2 ∘ / ∂ T ) p and the second derivatives ( ∂ 2 V 2 ∘ / ∂ T 2 ) p have also been estimated. These parameters have been utilized to understand various mixing effects in aqueous solutions due to the interactions between solute (saccharide) and co-solute (sodium acetate).

Densities, Refractive Indices and Excess Properties of N-p-Tolylbenzohydroxamic Acid in Dimethyl Sulfoxide at 298.15 to 313.15 K

Densities and refractive indices have been measured for N-p-tolylbenzohydroxamic acid (p-TBHA) in dimethyl sulfoxide (DMSO) as a function of concentration at (298.15, 303.15, 308.15, 313.15 and 318.15) K. The apparent molar volumes and partial molar volumes were obtained from these density data. The limited partial molar expansivities have been calculated from the temperature dependence of the limiting partial molar volume. The molar refractions were calculated from the experimental refractive index values for p-TBHA in DMSO. The excess volumes, deviations of the refractive indices, and molar refractions were also calculated. The results are discussed in terms of molecular interactions.