Interactions of some amino acids with aqueous manganese chloride tetrahydrate at T = (288.15 to 318.15) K: A volumetric and viscometric approach

Densities (ρ), sound velocities (u), and viscosities (η) of glycine, dl-α-alanine, dl-α-amino-n-butyric acid, l-valine, and l-leucine, in aqueous solutions (0.1, 0.5, 1.0, and 1.5) mol · kg⁻¹ of manganese chloride tetrahydrate, MnCl₂·4H₂O at different concentrations have been determined using a vibrating-tube digital densimeter, ultrasonic multifrequency interferometer and Ubbelohde type capillary viscometer attached with automatic viscosity measuring unit, respectively, within the temperature range (288.15 to 318.15) K. Partial molar volumes $V_2^{\text{o}}$, partial molar adiabatic compressibilities, $K_{\text{S,}2}^{\text{o}}$ and viscosity B-coefficients have been determined from the above measurements. Further these data were used to calculate the corresponding transfer parameters (${\mathrm{\Delta }}_{\text{t}}{V}_2^{\text{o}}$, ${\mathrm{\Delta }}_{\text{t}}{K}_{\text{S,}2}^{\text{o}}$ and Δ_tB), hydration numbers, n_H, side chain group contributions, partial molar expansibilities, $V_{\text{E}}^{\text{o}}$, dB/dT and related parameters. The data are discussed in terms of hydration of hydrophobic and hydrophilic parts of amino acids in these solutions.     

Excess molar volume along with viscosity,refractive index and relative permittivity for binary mixtures of exo-tetrahydrodicyclopentadiene with four octane isomers

The fundamental physical properties including density, viscosity, refractive index and relative permittivity, have been measured for binary mixtures of exo-tetrahydrodicyclopentadiene (JP-10) with four octane isomers (n-octane, 3-methylheptane, 2,4-dimethylhexane and 2,2,4-trimethylpentane) over the whole composition range at temperatures T = (293.15 to 313.15) K and pressure p = 0.1 MPa. The values of excess molar volume $\left(V_{\text{m}}^{\text{E}}\right)$, viscosity deviation (Δη), refractive index deviation (Δn_D) and relative permittivity deviation (Δε_r) are then calculated. All of the values of $V_{\text{m}}^{\text{E}}$ and Δη are observed to be negative, while those of Δn_D and Δε_r are close to zero. The effects of temperature and composition on the variation of $V_{\text{m}}^{\text{E}}$ values are discussed. The negative values of $V_{\text{m}}^{\text{E}}$ and Δη are conductive to high-density and low-resistance of fuels, which is favorable for the design and preparation of advanced hydrocarbon fuels.     

Ultrasonic velocities,densities, and excess molar volumes of binary mixtures of N,N-dimethyl formamide with methyl acrylate,or ethyl acrylate,or butyl acrylate,or 2-ethyl hexyl acrylate at T = 308.15 K

Ultrasonic velocities, u, densities, ρ, of binary mixtures of N,N-dimethyl formamide (DMF) with methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), and 2-ethyl hexyl acrylate (EHA), including pure liquids, over the entire composition range have been measured at T = 308.15 K. Using the experimental results, the excess molar volume, $V_m^E$, partial molar volumes, ${\overline{V}}_{m\text{,}1}$, ${\overline{V}}_{m\text{,}2}$, and excess partial molar volumes, ${\overline{V}}_{m\text{,}1}^E$, ${\overline{V}}_{m\text{,}2}^E$ have been calculated. Molecular interactions in the systems have been studied in the light of variation of excess values of calculated properties. The excess properties have been fitted to Redlich–Kister type polynomial and the corresponding standard deviations have been calculated. The positive values of $V_m^E$ indicate the presence of dispersion forces between the DMF and acrylic ester molecules. Further theoretical values of sound velocity in the mixtures have been evaluated using various theories and have been compared with experimental sound velocities to verify the applicability of such theories to the systems studied. Theoretical ultrasonic velocity data have been used to study molecular interactions in the binary systems investigated.     

Volumetric and ultrasonic behaviour of binary mixtures of 1-nonanol with o-cresol,m-cresol,p-cresol and anisole at T = (293.15 and 313.15) K

Densities, ρ, and speeds of sound, u, of binary liquid mixtures of 1-nonanol with o-cresol, m-cresol, p-cresol and anisole have been measured over the entire range of composition at T = (293.15 and 313.15) K and at atmospheric pressure. Using these data, the excess molar volume, V^E, molar free volume, V_f, parameters related to space-filling ability, V_f/V, non-linearity parameters, B/A, isentropic compressibility, κ_S, molar isentropic compressibility, K_S,m, deviation of molar isentropic compressibility, $K_{S\text{,}m}^E$, deviations of the speed of sound, u^D, and limiting excess partial molar volume, ${\overline{V}}_{m\text{,}i}^{E\text{,}0}$, and isentropic compressibility, ${\overline{K}}_{m\text{,}i}^{E\text{,}0}$, have been calculated. The calculated excess and deviation functions have been fitted to the Redlich–Kister polynomial equations and the results analyzed in terms of molecular interactions and structural effects.     

Volumetric properties of binary liquid mixtures: Application of the Prigogine–Flory–Patterson theory to excess molar volumes of dichloromethane with benzene or toluene

The values of the density were measured for binary liquid mixtures of benzene and toluene with dichloromethane over entire range of concentration using a vibrating-tube densimeter at T = (288.15, 293.15, 298.15, and 303.15) K and atmospheric pressure. The excess molar volumes, calculated from the density results, are positive for the systems of dichloromethane with benzene over the whole concentration range and present an approximate sigmoid curve for the dichloromethane with toluene. The $V_{\text{m}}^{\text{E}}$ values have been fitted to the Redlich–Kister polynomial equation, and other volumetric properties such as the partial molar volumes, $\overline{V_i}$, the apparent molar volume, V_?i, and the partial molar excess volumes at infinite dilution, $(\overline{V_i^{\text{E}}}{)}^{\infty }$, were calculated over the whole composition range. The Prigogine–Flory–Patterson (PFP) theory and its applicability in predicting $V_{\text{m}}^{\text{E}}$ at T = 298.15 K are tested. Good agreement was found for the mixtures dichloromethane with benzene. For the mixtures dichloromethane with toluene, which shows an approximate S-shaped $V_{\text{m}}^{\text{E}}$ behaviour, the correlation fails.