Molar Isentropic Compressibility Research Articles

Ultrasonic Velocity and Thermoacoustic Parameters for Copper(I) Nitrates in Dimethylsulfoxide with Pyridine as a Co-Solvent at 298 K

Aim: This study aimed to explore the ultrasonic velocity and thermoacoustic parameters for copper(I) nitrates in dimethylsulfoxide with pyridine as a co-solvent at 298 K. Background: Ultrasonic velocity variation and related factors provide a plethora of information regarding the acoustic behaviour of solutions. These studies help in understanding various kinds of interactions like ionic interactions in electrolytic solutions, molecular interactions in liquidliquid mixtures, and solute-solvent interactions. Objective: The objective of this study was to estimate the density (ρ) and ultrasonic velocity (u) of copper (I) nitrate complexes in the concentration range of 0.02-0.28 m.Kg-1 in dimethylsulfoxide (DMSO), pyridine (Py), and binary mixtures of DMSO+Py having 0, 20, 40, 60, 80, and 100-mole percentage of Py at 298 K and 1 atmospheric pressure. The study also aimed to determine the isentropic compressibility (κs) and apparent molal isentropic compressibility (κs,ø ) (which is the degree of electrostatic force occurring in solution) of various salts in the binary solvent mixtures using density values and ultrasonic velocities. Methods: Using long borosilicate glass tubes, the DSA 5000 M from Anton Parr was utilized to measure the density and ultrasonic velocity at 298 K operating at a frequency of 2 MHz. Results: The apparent molal isentropic compressibility (κs,ø) of the electrolytes was divided into the contributions of individual ions (κo s,ø)±. As the composition of the co-solvent increases, the (κo s,ø)± values for Cu (I) ions fall, i.e., they become more negative in magnitude. The (κo s,ø)± values for Bu4N+, Ph4B-, ClO4 -, and NO3 - are positive but decrease as they move to Py-rich regions. Strong structural effects due to interactions between solute-solute and solvent-solvent are indicated by negative (κo s,ø)± values. Thus, solvation increases in Py-rich regions. Furthermore, thermoacoustic parameters were evaluated from the experimentally measured values. The results were associated in terms of molecular interaction between the solute and the solvent, demonstrating that solutes have the potential to break or make structures with solvents. Conclusions: Experimental measurements of density (ρ), and ultrasonic velocities (u) in DMSO+Py at 298 K revealed that κo sϕ value for the copper(I) nitrates like [Cu(AN)4]+, [Cu(Phen)2]+ , [Cu(BN)4]+ [Cu(DMPhen)2]+ , [Cu(Bipy)2]+ , [Cu(TU)4]+, and the reference electrolyte decreases (less positive) or becomes more negative as the mole percentage of co-solvent increases. The κo sϕ values were further split to find the value of individual ions. The (κo s,ø)± values for Bu4N+, Ph4B-, ClO4 -, and NO3 - are positive but also show a decreasing trend in Py-rich regions. A negative (κo s,ø)± value indicates the presence of strong structural effects in the solvent mixture on the addition of electrolytes. Results show that solvation increases in Py-rich regions. Further correlating acoustic parameters in terms of molecular interactions also favored trends in the solvation behaviour of electrolytes. The increase in the value of Z depicts the formation of the H bond, which results in strong solute-solute interactions. The values of κs and Lf decreased as concentration increased for all the electrolytes, indicating a significant structure-forming tendency of copper(I) electrolytes in Py-rich locations. The value of RA also increases as the composition of the co-solvent increases, indicating stronger solvation behaviour in Py rich region. Lf and τ decreased as concentration increased for all the electrolytes, indicating strong interactions between the molecules of electrolytes with the solvent in Py-rich regions.

Insight into molecular interactions and solvation properties of methylammonium perchlorate in acetonitrile-dimethylsulfoxide binary mixtures: Compressibility, viscometric and dissolution thermodynamic studies

Densities (ρ), ultrasonic velocities (u) and viscosities (ƞ) of Methylammonium perchlorate (CH3NH3ClO4) in binary solvent mixtures of Acetonitrile (AN) and Dimethylsulfoxide (DMSO) containing 0.0, 0.20, 0.40, 0.60, 0.80 and 1.0 ​mol fraction of DMSO at various temperatures ranging from 298K–328K at atmospheric pressure, have been measured. From the experimental data important parameters, namely, apparent molal volume (VΦ), isentropic compressibility (Ks), limiting apparent molal isentropic compressibility (Kos,ɸ), A and B-viscosity coefficients from Jones-Dole equation, B/Vɸo values and viscous flow related thermodynamic properties have been derived. Interpretation of the obtained thermodynamic parameters was done with regards to solute-solvent and solute-solute interactions and structure breaking and making potential of the solutes in solution. To evaluate the extent of preferential solvation, Kos,ɸ values and B-coefficients for the electrolytes have been further split up into the contribution of individual ion (Kos,ɸ± and B± values) by reference electrolyte method.

Investigation on stability, density and viscosity of ZnO/PEG nanofluids in the presence of 1-butyl 3-methylimidazolium chloride and 1-butyl 3-methylimidazolium bromide ionic liquids

Addition of ionic liquids (ILs) into the fluids containing nanoparticles is often used to minimize particle aggregation and improve dispersion behavior of nanofluids. However, they also affect the physical characteristics of liquids, such as thermophysical properties and viscosity. The aim of this work was to investigate the role of 1-butyl 3-methylimidazolium bromide [C4mim][Br] and 1-butyl 3-methylimidazolium chloride [C4mim][Cl] on the dispersion stability, volumetric characterizations and viscosity of polyethylene glycol 200 (PEG 200) nanofluids containing ZnO nanoparticles. Particle size distribution of these nanofluids has been studied by UV–Vis spectroscopy and dynamic light scattering (DLS). The obtained results show that the nanofluids with PEG 200 + [C4mim][Cl] have lower stability than PEG 200 + [C4mim][Br]. Additionally, in order to understand molecular interactions between components of studied nanofluids (ZnO, PEG 200 and ILs) the density (d), speed of sound (u) and viscosity ( $$\eta$$ ) of these nanofluids were measured at 293.15, 298.15, 308.15 and 308.15 K. The excess molar volume ( $$V_{m}^{E}$$ ), apparent molar volume ( $$V_{\phi }$$ ) and isentropic compressibility ( $$\kappa_{s}$$ ) have been calculated using density and speed of sound data. These properties can help us to discuss about the stability and volumetric characterizations of the nanofluids. Also, theoretical analyses of $$V_{m}^{E}$$ , $$\kappa_{s}$$ and $$\eta$$ were performed using some existing models (Ott et al., Redlich–Kister, Eyring-mNRF and Eyring-NRTL) and the obtained results were compared with experimental data.

Solvation Behaviour of Some Copper(I) Nitrate Complexes in Dimethylsulfoxide and Nitromethane at 298 K

The ultrasonic velocities of solutions of Bu4NBPh4, Bu4NClO4, [Cu(AN)4]NO3, [Cu(BN)4]NO3, [Cu(Phen)2]NO3, [Cu(DMPhen)2]NO3, [Cu(Bipy)2]NO3 and [Cu(TU)4]NO3 (where AN = acetonitrile, BN = benzonitrile, Phen = 1,10-phenanthroline, DMPhen = 2,9-dimethyl-1,10-phenanthroline, Bipy = 2,2′-bipyridyl and TU = thiourea) were measured in the concentration range 0.03-0.27 M in dimethylsulfoxide (DMSO), nitromethane (NM) and binary mixtures of DMSO + NM containing 0, 20, 40, 60, 80 and 100 mol% NM at 298 K in the present studies. Using ultrasonic velocity and density data, isentropic compressibility (κs) and apparent molal isentropic compressibility (κs,φ) for electrolytes in DMSO + NM mixture have been calculated. Result shows that copper(I) electrolytes show less solvation in NM rich regions indicating structure breaking tendency of nitromethane. Extent of solvation in Cu(I) ions decreases in the order: [Cu(AN)4]+ > [Cu(BN)4]+ > [Cu(TU)4]+ > [Cu(DMPhen)2]+ > [Cu(Phen)2]+ > [Cu(Bipy)2]+.

Ion-Solvent Interactions Investigated by Isentropic Compressibility Measurements of Lithium and Sodium Salts in Binary Mixtures of Acetonitrile and Nitromethane at 298.15 K

Ultrasonic velocities (u) and densities (ρ) of lithium perchlorate (LiClO4), sodium perchlorate (NaClO4), sodium tetraphenylborate (NaBPh4), tetrabutylammonium tetraphenylborate (Bu4NBPh4) and tetrabutylammonium perchlorate (Bu4NClO4) were measured in the concentration range 0.001-0.25 mol kg-1 in acetonitrile (AN) and nitromethane (NM) binary mixtures consisting of 0, 20, 40, 60, 80 and 100 mol%NM in AN at 298.15 K. The isentropic compressibility (Ks) and apparent molal isentropic compressibility (Ks,f) values of the above salts in all solvent mixtures have been evaluated from experimental data. Limiting apparent molal isentropic compressibilities (Ko s,φ) for various salts were evaluated and split into the ionic contributions (Ko s,φ)±. The variation of (Ko s,φ)± with solvent compositions shows that Li+ and Na+ ions have very large negative (Ko s,φ)± values indicating strong solvation of both Li+ and Na+ ions in AN + NM mixtures over whole binary solvent composition range. Stronger solvation was further observed in the intermediate compositions of AN + NM mixtures. Li+ ions, however, showed much higher solvation as compared to Na+ ions at all compositions. The ClO4 – ions showed feeble solvation in AN + NM mixtures through some interaction with AN binary mixtures with higher mol% of AN. The positive values of (Ko s,φ)± with large magnitude for Bu4N+ and Ph4B– ions indicate solvophobic type of interaction with the solvent molecules, which is stronger in the intermediate compositions of AN + NM mixtures.

Ultrasonic Velocity and Isentropic Compressibility Studies of Monoalkylammonium Salts in Binary Mixtures of Acetonitrile and N,N-Dimethylacetamide at Variable Temperature and Atmospheric Pressure

Ultrasonic velocities and densities of alkyl substituted ammonium perchlorates-RNH3ClO4, where R is methyl (Me), ethyl (Et),n-propyl (Pr),n-butyl (Bu),n-hexyl (Hx) and n-octyl (Oc), have been measured in the concentration range 0.03–0.28 mol·kg−1 in binary mixtures of acetonitrile (AN) and N,N-dimethylacetamide (DMA) containing 0, 20, 40, 60, 80 and 100 mol% DMA at temperatures 298–328 K in 10 K intervals, using an Anton Paar density and sound velocity meter (DSA 5000 M). The experimental data of ultrasonic velocities and densities have been used for calculating isentropic compressibilities ( $$K_{{S}}$$ ) and apparent molal isentropic compressibilities ( $$K_{{{S,}\phi }}$$ ). Limiting apparent molal isentropic compressibilities ( $$K_{{{S,}\phi }}^{{\text{o}}}$$ ) for all the electrolytes have been evaluated from $$K_{{{S,}\phi }}$$ against m1/2 plots and split into contributions of individual ion ( $$K_{{{S,}\phi , \pm }}^{{\text{o}}}$$ ). The variation of $$K_{{{S,}\phi , \pm }}^{{\text{o}}}$$ values with solvent composition shows preferential solvation of alkylammonium ( $${\text{RNH}}_{3}^{ + }$$ ) ions by DMA in the AN rich region and by AN in the DMA rich region. The extent of solvation of the alkylammonium ions, at all studied temperatures, was found to increase with decreasing alkyl chain length; that is $${\text{OcNH}}_{3}^{ + }$$ < $${\text{HxNH}}_{3}^{ + }$$ < $${\text{BuNH}}_{3}^{ + }$$ < $${\text{PrNH}}_{3}^{ + }$$ < $${\text{EtNH}}_{3}^{ + }$$ < $${\text{MeNH}}_{3}^{ + }$$ . $$K_{{{S,}\phi , \pm }}^{{\text{o}}}$$ values for all $${\text{RNH}}_{3}^{ + }$$ ions increase with increasing temperature, indicating a decrease in the solvation of the ions with increasing temperature.

Investigations on the interactions in the Binary Mixtures of Tripropylene Glycol Monomethyl Ether (TPGMME) and 1-Heptanol at Different Temperatures

Densities (ρ) and ultrasonic speeds (u) of the binary liquid mixtures of Tripropylene Glycol Monomethyl Ether (TPGMME) and 1-haptanol have been measured as a function of composition at temperature range of 288.15 to 318.15 K and atmospheric pressure. The measurements have been carried out using an Anton Paar density and speed of sound analyser DSA 5000. Thermodynamic properties like excess molar volumes, isentropic compressibility and molar isentropic compressibility have been calculated by using densities and speed of sound data at various temperatures. Value for excess molar volume is positive for (TPGMME) and 1-haptanol over the entire mole fraction range, and increase with increasing temperature.

Thermo-physical and spectroscopic studies of liquid mixtures containing p-methoxy benzoic acid

ABSTRACT The density and speed of sound were measured for p-Methoxy benzoic acid (P-MBA) with Aniline, N-Methylaniline (NMA) and N, N-dimethylaniline (NNDMA) from (303.15 K–313.15 K) with 5K interval temperatures using standard techniques. Thermo physical properties of molar volume (Vm ), acoustic impedance (Z), isentropic compressibility (κs ), surface tension (σ) and free length (Lf ) and their excess properties were intended from measured data. These excess parameters have been fitted to the Redlich–Kister type polynomial equation using the least square method. Obtained values of partial molar volumes ( , ) reflects the culminations were drawn from Vm E. Supplementary, to test the pertinent of different theoretical models of speed of sound by means of resoluted values. Finally, the formation of hydrogen bonding between molecules in composition was fetched from FTIR spectra.

Thermodynamic and transport investigation of aqueous solutions containing choline L-histidinate and some water soluble polymers such as polyethylene glycol di methyl ether, polyethylene glycol and polypropylene glycol: Evaluation of solute-solvent interactions and phase forming ability

Considering to the importance of choline amino acid ionic liquids, [Ch][AA]-ILs, as green biocompatible and biodegradable solvents utilized for separation of proteins through inducing aqueous biphasic systems in the presence of some water soluble polymers, it is vital to elucidate the solute-solute and solute-solvents interactions in water media which may be responsible for phase separation. In this respect, density, sound speed and viscosity of choline L-histidine, [Ch][L-His], in water and aqueous solutions of three polymers containing polyethylene glycol dimethyl ether 250, PEGDME250, polypropylene glycol 400, PPG400, and polyethylene glycol 400, PEG400, have been measured experimentally at T = (288.15 to 318.15) K and 298.15 K under atmospheric pressure, respectively. The obtained data from these measurements were employed for computing the limiting values for apparent molar volume (Vφ0), molar isentropic compressibility (κφ0), transfer molar volume (ΔtransVφ0) and isentropic compressibility (Δtransκφ0) for transferring [Ch][L-His] from water to aqueous polymer solutions, viscosity B-coefficient, transfer viscosity B-coefficient (ΔtransB), free energies of activation per mole of solvent (Δμ10≠) and solute (Δμ20≠). These quantities provide some useful information about [Ch][L-His]-polymer and [Ch][L-His]-water interactions, soluting-out ability of IL and capability of above ternary solutions for separation into two-phases. The results showed that the ΔtransVφ0 values for PPG and PEGDME are negative which indicates that IL-water interactions become stronger in the presence of these polymers. But, in the case of PEG, a positive value of ΔtransVφ0 shows that the IL-water interactions are weaker in the presence of this polymer.

Thermophysical and thermodynamic properties of 1-ethyl-3-methylimidazolium ethylsulphate ionic liquid and its binary mixtures with pentanoic or 2-methylpropanoic acid at various temperatures

ABSTRACTPhysicochemical properties comprising densities (ρ), speed of sound (u) and refractive indices ( for [EMIM]⁺[EtSO4]⁻, pentanoic acid, 2-methylpropanoic acid and binary mixtures containing {[EMIM]⁺[EtSO4]⁻ + pentanoic or 2-methylpropanoic acid} were determined across the entire mole fraction range of concentrations from 0.1 to 1.0 at T = 288.15 K to 313.15 K, under atmospheric pressure. The following thermodynamic properties: excess molar volumes (), isentropic compressibility and deviation in isentropic compressibility were computed from the measured and values. Furthermore, together with for the binary systems were negative over the entire mole fraction range at fixed temperature but increases with increasing temperature. The Redlich-Kister polynomial equation was used to correlate the derived properties with resulting values. The results obtained from this study have been discussed in terms of intermolecular interactions, H-bonding, ionic interactions and dipole moments in the binary mixtures of the ionic liquid and carboxylic acids.

Excess molar volumes and excess isentropic compressibilities of mixtures containing lactam, cyclic ethers and cyclic alkanones

Abstract Measurements of densities, ρ, ρ123 and speeds of sound, u, u123 of binary 1,3-dioxolane (1) + 1,4-dioxane (2) and ternary 1,3-dioxolane (1) + N-methylpyrrolidi-2-one or 1,4-dioxane (2) + cyclohexanone or cycloheptanone (3) mixtures have been carried out over the entire range of mole fraction at 293.15, 298.15, 303.15, 308.15 K and atmospheric pressure. The excess molar volumes, V 12 E , V 123 E and excess isentropic compressiblities, ( κ S E ) 12 , ( κ S E ) 123 have been determined from experimental data. The V 123 E and ( κ S E ) 123 data for 1,3-dioxolane (1) + N-methylpyrrolidin-2-one (2) + cyclohexanone or cycloheptanone (3) and 1,3-dioxolane (1) + 1,4-dioxane (2) + cycloheptanone (3) mixture are negative over entire composition of (1) and (2). While V 123 E for 1,3-dioxolane (1) + 1,4-dioxane (2) + cyclohexanone (3) are positive across full range of compositions of (1) and (2); the sign and magnitude of ( κ S E ) 123 values vary with change in composition of the constituent molecules. The V 12 E , V 123 E and ( κ S E ) 12 , ( κ S E ) 123 data have been fitted to Redlich-Kister equation to determine binary, ternary adjustable parameters and standard deviations. The V 123 E and ( κ S E ) 123 data have been analyzed in terms of Graph Theory. It has been observed that Graph theory correctly predicts the sign as well as magnitude of V 123 E and ( κ S E ) 123 data of the studied ternary mixtures.

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.

Acoustical studies of pharmaceutical excipients in binary solvent mixtures

Pharmaceutical excipients have gained a great importance due to their control of blood glucose level and sugar alternative. Thermodynamic methods provide an easy way for determination of solute-solute and solute-solvent interactions in solutions. Density and sound velocity for sugar alcohols have been measured in binary mixtures of Dimethyl Sulfoxide-Water at different percentage compositions (i.e. 10%–50%) at different temperatures. Density and sound velocity data have been used to calculate apparent molal volume, apparent molal isentropic compressibility, partial molal volume, partial molal isentropic compressibility, intermolecular free length, relative association, Rao's molar sound function and solvation number. Results have been discussed in terms of solvent-solvent, solute-solute and solvent-solute interactions. For all the systems studied, the density, sound velocity and apparent molal volume increase with increasing concentration of sugar alcohols which indicates the presence of solute-solvent interactions. The value of partial molal volume also increases with increasing temperature. The values of Sv are found positive while the values of apparent molal isentropic compressibility are negative which indicates the presence of solute-solvent interactions.

Characterizaton and Volumetric Studies of Magnetite (Fe&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;) Nanofluids at Different Temperatures

Magnetite nanofluid has been prepared in citric acid based medium. Their stability and polydispersity level have been characterized by UV-visible spectrophotometry.The volumetric properties such as apparent molar volume, partial molar volume and isentropic compressibility of nanofluid have been measured at temperature range from 298.15K to 313.15K at atmospheric pressure. The obtained results were interpreted in terms of particle-particle and particle-fluid interactions, and compared with commercially available magnetite nanofluid in terms of particle size difference. It was observed that the influence of particle size on measured volumetric parameters is significant for any practical applications of fluid flow. The differences in measured quantities were determined qualitatively by considering the state of aggregation / particle size distribution of the nanofluids.

Excess molar volume and isentropic compressibility of monoethanolamine in aqueous system at temperatures from 298.15 to 318.15 K

ABSTRACTDensities and sound velocities for aqueous monoethanolamine (MEA) system are reported over the entire composition range at different temperatures (298.15, 303.15, 313.15 and 318.15 K). These experimental data have been further used in calculating the excess molar volume, partial molar volumes, isobaric thermal expansion coefficients and the deviation in isentropic compressibility. The excess molar volumes data were fitted to the Redlich–Kister polynomial equation to obtain their coefficients and standard deviations. The partial molar volume at infinite dilution of both water in MEA and MEA in water and have been determined using two different methods. Knowledge of the above properties of these mixtures is a basis for understanding some of the molecular interactions in these systems. From the analysis of the results, the type of interactions between the MEA and water is discussed in terms of the number and size of the alkyl groups attached to the nitrogen atom of MEA.

Ultrasonic Velocity and Compressibility Studies of Tetraalkylammonium Salts in Acetonitrile + Methanol Binary Mixtures at 298.15 K

Abstract The ultrasonic velocities (u) and densities (ρ) of tetraalkylammonium perchlorates (R4NClO4, where R = Methyl, Ethyl, Propyl or Butyl) and tetrabutylammonium tetraphenylborate (Bu4NPh4B) solutions have been measured at different salt concentrations in the range (30–500) × 10−4 mol kg –1 in binary mixtures of acetonitrile (AN) with methanol (MeOH) containing 0, 20, 40, 60, 80 and 100 mol % methanol at 298.15 K. The isentropic compressibilities (K s ) and apparent molal isentropic compressibilities (K s,φ ) of different salts in the solvent mixtures have been calculated. Limiting apparent molal isentropic compressibilities (K o s,φ ) for various salts have been evaluated and split into contributions of individual ions i.e., into (K o s,φ )± values. The variation of (K o s,φ )± values with solvent composition shows that Bu4N+ and Ph4B+ have very large positive (K o s,φ )± values which show strong solvophobic interactions in AN and in AN + MeOH mixtures over the entire solvent composition range. These positive values indicate some special type of interactions with the solvent molecules, which increase with the increase of MeOH composition. ClO4 – shows much weaker solvation in AN + MeOH mixtures by having some interaction with AN in the AN rich region of the mixtures. The negative values of Me4N+ and Et4N+ ions show strong structural effects which arise due to solute-solvent interactions in MeOH rich region of mixtures.

Sound Velocities and Micellar Behaviour Studies of Dodecyltrimethylammonium Bromide in Aqueous Solutions at 295.15, 302.15 and 309.15 K

Speed of sound, u, of dodecyltrimethylammonium bromide (DTAB) aqueous solutions has been determined at 295.15, 302.15 and 309.15 K. The speeds of sound, u, data have been used to estimate isentropic compressibility, Ks, apparent molal isentropic compressibility, φk(s), acoustic impedance, Z, molal sound of speed, Rm, and relative association, RA, of DTAB in aqueous solution. These parameters have been interpreted in terms of solute-solute and solute-solvent interactions and micellar behavior of DTAB.

Volumetric and transport properties of the ternary mixtures of toluene (1) + benzene (2) + butyl acetate (3) at different temperatures

Densities, ρ, speeds of sound, u, and viscosities, η, of ternary mixtures containing toluene, benzene and butyl acetate and binary mixtures formed by toluene and butyl acetate are reported in this paper. From experimental data, excess molar volumes, VE, isentropic compressibilities, κs, and excess isentropic compressibilities, , were evaluated. The calculated magnitudes were fitted to different equations available on the literature, and geometrical models have been used to predict ternary magnitudes from the binary ones. Furthermore, viscosities were predicted by group contribution models. The results have been discussed in terms of molecular interactions among the components of the mixtures.

Influence of sodium acetate on the volumetric behavior of binary mixtures of DMSO and water at 298.15 to 313.15 K

Density data of sodium acetate trihydrate in the binary mixtures of dimethyl sulfoxide and water at different percentage compositions (i.e. 10%–75%) have been determined at 298.15, 303.15, 308.15 and 313.15K temperatures and atmospheric pressure. The ultrasonic speed in electrolytic solution has also been determined at 298.15K. Apparent molar volume (Vϕ), adiabatic compressibility (K) and isentropic compressibility (Kϕ) of these electrolytic solutions were calculated from the experimental density and sound velocity data. These parameters have been used to evaluate partial molar volume (Voϕ) and partial molal isentropic compressibility (Koϕ). The density data was evaluated by using Masson equation. The derived parameters have been discussed in terms of ion–ion and ion–solvent interactions.