scholarly journals Volumetric behaviour of tetra-n-butyl ammonium bromide in various solvents at different temperatures

Author(s):  
Shipra Baluja ◽  
Elham Abdullah Mo Alnayab

Measurement of ultrasonic velocity, density and viscosity of solutions of Tetra Butyl Ammonium Bromide have been carried outin different solvents (water, methanol, ethanol, 1-propanol and 1-butanol) as functions of concentration (1 to 0.1 M) at different temperatures (298.15 K to 318.15 K). Using these experimental data, various acoustical and apparent parameters such as acoustical impedance, intermolecular free length, adiabatic compressibility, molar compressibility, Van der Waals constant, relaxation strength, apparent molar isentropic compressibility, apparent molar volume have been evaluated. Further, some thermodynamic parameters such as Gibbs free energy of activation, enthalpy and entropy of activation have been evaluated. All these parameters have been evaluated to understand type of interactions present in studied solutions.

Author(s):  
Bhavin. B. Dhaduk ◽  
Parsotam H. Parsania

Density (ρ), viscosity (η), ultrasonic speed (U), and thermo-acoustical parameters such as specific acoustical impedance (Z), adiabatic compressibility (κa), internal pressure (π), free volume (Vf), inter molecular free path length (Lf), Van der Waals constant (b), viscous relaxation time (τ), classical absorption coefficient (α/f2)cl, Rao’s molar sound function (Rm), solvation number (Sn), Gibbs free energy of activation (ΔG*), enthalpy of activation (ΔH*) and entropy of activation (ΔS*) of biologically active 1,1’-bis (3-methyl-4-carboxyethylphenoxy) cyclohexane (BMCPC) in 1,4-dioxane (DO), ethyl acetate (EA), tetrahydrofuran (THF) have been studied at four different temperatures: 298, 303, 308 and 313 K to understand the molecular interactions in the solutions. A good to excellent correlation between a given parameter and concentration is observed at all temperatures and solvent systems studied. Linear increase or decrease [except (α/f2)cl ] of acoustical parameters with concentration and temperature indicated the existence of strong molecular interactions. ΔG* decreased linearly with increasing concentration and temperature in DO and EA systems and increased with temperature in THF system. ΔH* and ΔS* are found practically concentration independent in case of DO and EA system but both are found concentration dependent in THF system.


2018 ◽  
Vol 232 (3) ◽  
pp. 393-408 ◽  
Author(s):  
Dinesh Kumar ◽  
Shashi Kant Sharma

AbstractDensities,ρand ultrasonic speeds, u of L-histidine (0.02–0.12 mol·kg−1) in water and 0.1 mol·kg−1aqueous citric acid solutions were measured over the temperature range (298.15–313.15) K with interval of 5 K at atmospheric pressure. From these experimental data apparent molar volume ΦV, limiting apparent molar volume ΦVOand the slopeSV, partial molar expansibilities ΦEO, Hepler’s constant, adiabatic compressibilityβ, transfer volume ΦV, trO, 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 in these systems. It has also been observed that L-histidine act as structure maker in water and aqueous citric acid.


Author(s):  
Baljeet Singh Patial

Ultrasonic velocities (u), densities (ρ) and viscosities (η) are measured in respect of ethylmethylketone (EMK) and N,N-dimethylformamide (DMF) over the entire composition at 298, 308and 318K. Attempt have been made to extract the information with respect to various kind of intermolecular interactions, such as H-bonding, dipole-dipole, solute –solvent, dispersion type interactions existing between these two components from the following acoustical parameter when examined as a function of solvent composition at different temperatures: adiabatic compressibility (β), specific acoustic impedance (Z), intermolecular free length (Lf), molar sound velocity (Rm), wada’s constant (W), viscous relaxation time (τ), free volume and internal pressure (πi).


In this paper, the authors have given information regarding intermolecular interactions of aqueous dextran solution in urea. The behavior of dextran in urea has been examined by the help of ultrasonic interferometer working at frequency 5MHz at different temperatures ranging from 303 K to 323 K in 5K interval. Ultrasonic speed, density, viscosity measurements have been used for the evaluation of thermodynamic parameters like Gibb’s free energy (ΔG) as well as acoustical parameters are acoustic impedance (Z), isentropic compressibility (β), intermolecular free length (Lf ) and relaxation time (τ), etc. The results have been used to throw light on the nature of the interaction among solute and solvent, interpreted in the light of structural rearrangement occurs in the aqueous dextran and urea solution.


2020 ◽  
Vol 10 (2) ◽  
pp. 5259-5265

The densities (ρ), and ultrasonic velocities (u) of 1-Butyl-2, 3-dimethylimmidazolium chloride,[bdmim]Cl in aqueous solutions of Tetra-n-butyl ammonium bromide over the complete range of concentrations has been calculated at different temperatures T= (298.15 to 313)K. Experimentally obtained values of ρ and u were used to calculate the parameters like acoustic impedance (Z), isentropic compressibility (βS), molar sound velocity (Rao’s constant) (R), molar compressibility (Wada’s constant)(W), intermolecular free length (Lf), co-efficient of thermal expansion (α), heat capacity ratio (γ), isothermal compressibility (βT) and nonlinearity parameters (B/A). The final results obtained were analyzed to understand the ion-solvent and ion-ion interaction so taking place in the solutions. Further, the effect of temperature on the ion solvent interactions was discussed. Ion-solvent interactions are affected by the thermo acoustical properties and by nonlinear parameters.


Author(s):  
Mrunal M. Mahajan ◽  
Pravin B. Raghuwanshi

<div><p><em>The present work deals with the study of acoustic parameters like ultrasonic velocity (V), </em><em>adiabatic compressibility (β<sub>s</sub>), apparent molar volume (</em><em>f</em><em><sub>v</sub></em><em>) and intermolecular free length (L<sub>f</sub>) by ultrasonic </em><em>interferometric measurements</em><em> which reflects structural interaction of water molecules and organic solvent molecules with substituted Schiff bases. The study of N–(2-hydroxybenzylidene)-3-substituted pyridine -2- amine Schiff bases were carried in different percentage of 1,4-dioxane-water medium, at 293, 297 and 300 K. The densities and velocities thus obtained were used to evaluate acoustic parameters for all the ligands.</em></p></div>


2019 ◽  
Vol 31 (4) ◽  
pp. 960-964
Author(s):  
S. Farook Basha ◽  
M. Syed Ali Padusha

This work deals with the ultrasonic studies of the Mannich bases (morpholin-4-yl)(pyridin-3- yl)methyl]hydrazine carboxamide (MPH) and (morpholino)(thiophen-2-yl)methyl)nicotine hydrazide (MTN) by the measurements of parameters such as ultrasonic velocity (U), density (ρ), viscosity (η), adiabatic compressibility (κ), intermolecular free length (Lf), molar volume (Vm), relaxation time (τ), specific acoustic impedance (Z), lenard jones potential (LJP), internal pressure (πi), free volume (Vf) and molecular cohesive energy (MCE), available volume (Va), Gibbs free energy (ΔG) and absorption coefficient (α/f2). These results are inferred that the strong interaction exists between the solvent (DMSO) and solute (MPH and MTN).


Author(s):  
B. Sudhamsa ◽  
M. Sarath Babu ◽  
K. Narendra

The speed of sound and density in binary liquid mixture of diethyl carbonate + benzonitrile, + benzaldehyde have been determined at temperatures 298.15, 308.15 and 318.15 K over the whole composition range. The data have been utilized to estimate the excess adiabatic compressibility (βE), excess intermolecular free length (LfE), excess speed of sound (uE) at the above temperatures. The excess values have been found to be useful in estimating the strength of the interactions in the liquid mixtures.


Acta Naturae ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 29-37 ◽  
Author(s):  
O. A. Kladova ◽  
N. A. Kuznetsov ◽  
O. S. Fedorova

In the present work, a thermodynamic analysis of the interaction between endonuclease VIII (Endo VIII) and model DNA substrates containing damaged nucleotides, such as 5,6-dihydrouridine and 2-hydroxymethyl-3-hydroxytetrahydrofuran (F-site), was performed. The changes in the fluorescence intensity of the 1,3-diaza-2-oxophenoxazine (tCO) residue located in the complementary chain opposite to the specific site were recorded in the course of the enzyme-substrate interaction. The kinetics was analyzed by the stopped-flow method at different temperatures. The changes of standard Gibbs free energy, enthalpy, and entropy of sequential steps of DNA substrate binding, as well as activation enthalpy and entropy for the transition complex formation of the catalytic stage, were calculated. The comparison of the kinetic and thermodynamic data characterizing the conformational transitions of enzyme and DNA in the course of their interaction made it possible to specify the nature of the molecular processes occurring at the stages of substrate binding, recognition of the damaged base, and its removal from DNA.


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