DR VRIJESH K U M A R PANDEY (original) (raw)

Papers by DR VRIJESH K U M A R PANDEY

Journal of Solution Chemistry, Nov 5, 2020

Experimental refractive index, n D , data for eleven binary systems of 2-diethylethanolamine (2-D... more Experimental refractive index, n D , data for eleven binary systems of 2-diethylethanolamine (2-DEEA) + 1-propanol/1-butanol at different temperatures from T = 293.15 to 313.15 K and at atmospheric pressure, over the whole concentration range, are reported. The molar refractions (R m), molecular radii (r) , reduced molar free volumes V m ∕R m , internal pressure, P int and the deviations of refractive indices Δn D , molar refraction ΔR m , reduced molar free volumes Δ V m ∕R m , and internal pressure Δ P int were also calculated from the experimental data. Nine mixing rules, viz. those of Arago and Biot, Newton, Heller, Gladstone and Dale, Eyring and John, Eykman, Lorentz and Lorentz, Weiner and Oster are used to predict the refractive indices of the binary liquid systems. Among all, the Weiner method (W) is in best agreement with the experimental results.

Indian Journal of Pure & Applied Physics, Nov 26, 2019

The density (ρ) and refractive indices (n D) of binary mixtures of formamide (FA) with dimethylet... more The density (ρ) and refractive indices (n D) of binary mixtures of formamide (FA) with dimethylethanolamine (DMEA) and diethylethanolamine (DEEA) have been recorded at different temperatures for the whole composition ranges. The experimental values of density data and refractive index are used to estimate the molar refraction (R m), reduced molar free volume (V m /R m), molecular radii (r) and internal pressure (P int). The deviations of refractive index (Δn D), molar refractions (ΔR m), reduced molar free volumes Δ (V m /R m) and internal pressures (ΔP int) have been also calculated. The variations of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions due to physical, chemical and structural effects between the unlike molecules. The applicability of different refractive index mixing rules is tested against the experimentally measured values and good agreement has been obtained.

Journal of Molecular Liquids, Jul 1, 2016

Density (ρ) and ultrasonic velocity (μ) data of binary mixtures of formamide (FA) with 2-dimethyl... more Density (ρ) and ultrasonic velocity (μ) data of binary mixtures of formamide (FA) with 2-dimethylaminoethanol (DMAE) and 2-diethylaminoethanol (DEAE) have been measured experimentally over the whole range of compositions at 303.15, 313.15 and 323.15 K. The ultrasonic velocity and density data are used to determine adiabatic compressibility (β), intermolecular free length (L f) and specific acoustic impedance (Z) along with their excess values as V m E , u E , β S E and Z E. The IR spectra of binary mixtures formamide + 2-dimethylaminoethanol and formamide + 2-diethylaminoethanol have also been recorded at room temperature 303.15 K. The variation of these parameters with composition and temperature are discussed in terms of molecular interactions of these mixtures.

The Journal of Chemical Thermodynamics, Nov 1, 2018

Thermochimica Acta, Jun 1, 2014

The densities (ρ), ultrasonic speeds (u) and viscosities (η) are reported for binary mixtures of ... more The densities (ρ), ultrasonic speeds (u) and viscosities (η) are reported for binary mixtures of 2-methylaniline with isomeric chlorotoluenes namely o-chlorotoluene, m-chlorotoluene and p-chlorotoluene over the entire range of mole fractions at temperatures 303.15, 308.15, 313.15 and 318.15 K and at atmospheric pressure. The excess properties such as excess molar volume, excess isentropic compressibility and deviation in viscosity are calculated from the density, speed of sound and viscosity and the Redlich-Kister equation, correlates these properties. The excess partial molar properties

Thermochimica Acta, Oct 1, 2018

Highlights: 1. Hydrogen bonding occurs between FA+2-DMAE /2-DEAE molecules 2. Molecular associati... more Highlights: 1. Hydrogen bonding occurs between FA+2-DMAE /2-DEAE molecules 2. Molecular association follows: FA + 2-DEAE > FA + 2-DMAE  2 , ,), at infinite dilution, over the entire composition range are also calculated. The knowledge of the volumetric properties and molar compression aids to understand specific molecular interactions existing between the FA and 2-DMAE/ 2-DEAE molecules of the binary system. The strength of intermolecular interactions in these mixtures follows the order: FA+ 2-DEAE > FA + 2-DMAE. The required experimental data are used from our earlier work on the volumetric and acoustic study published in J. Mol. Liqs. 219 186 (2016).

Zenodo (CERN European Organization for Nuclear Research), Sep 13, 2022

Thermochimica Acta, 2018

Highlights: 1. Hydrogen bonding occurs between FA+2-DMAE /2-DEAE molecules 2. Molecular associati... more Highlights: 1. Hydrogen bonding occurs between FA+2-DMAE /2-DEAE molecules 2. Molecular association follows: FA + 2-DEAE > FA + 2-DMAE  2 , ,), at infinite dilution, over the entire composition range are also calculated. The knowledge of the volumetric properties and molar compression aids to understand specific molecular interactions existing between the FA and 2-DMAE/ 2-DEAE molecules of the binary system. The strength of intermolecular interactions in these mixtures follows the order: FA+ 2-DEAE > FA + 2-DMAE. The required experimental data are used from our earlier work on the volumetric and acoustic study published in J. Mol. Liqs. 219 186 (2016).

Physics and Chemistry of Liquids, 2020

This work reports the volumetric properties of binary mixtures of 2-dimethylaminoethanol (DMAE) a... more This work reports the volumetric properties of binary mixtures of 2-dimethylaminoethanol (DMAE) and 2-diethylaminoethanol (DEAE) with dimethylsulfoxide (DMSO) as a function of composition in the temperature range 298.15-318.15 K at atmospheric pressure. The excess molar volumes, apparent molar volumes, and excess partial molar volumes of both the components were determined in order to reflect several aggregation patterns present in the binary solvent system. The excess molar volumes show positive deviations from ideality. The excess partial molar volumes show complex dependence on composition and temperature. The results were used to investigate intermolecular interaction and structural configuration in these mixtures.

Journal of Molecular Liquids, 2016

Density (ρ) and ultrasonic velocity (μ) data of binary mixtures of formamide (FA) with 2-dimethyl... more Density (ρ) and ultrasonic velocity (μ) data of binary mixtures of formamide (FA) with 2-dimethylaminoethanol (DMAE) and 2-diethylaminoethanol (DEAE) have been measured experimentally over the whole range of compositions at 303.15, 313.15 and 323.15 K. The ultrasonic velocity and density data are used to determine adiabatic compressibility (β), intermolecular free length (L f) and specific acoustic impedance (Z) along with their excess values as V m E , u E , β S E and Z E. The IR spectra of binary mixtures formamide + 2-dimethylaminoethanol and formamide + 2-diethylaminoethanol have also been recorded at room temperature 303.15 K. The variation of these parameters with composition and temperature are discussed in terms of molecular interactions of these mixtures.

Journal of Molecular Liquids, 2015

Experimental refractive index, n D , data for eleven binary systems of 2-diethylethanolamine (2-D... more Experimental refractive index, n D , data for eleven binary systems of 2-diethylethanolamine (2-DEEA) + 1-propanol/1-butanol at different temperatures from T = 293.15 to 313.15 K and at atmospheric pressure, over the whole concentration range, are reported. The molar refractions (R m), molecular radii (r) , reduced molar free volumes V m ∕R m , internal pressure, P int and the deviations of refractive indices Δn D , molar refraction ΔR m , reduced molar free volumes Δ V m ∕R m , and internal pressure Δ P int were also calculated from the experimental data. Nine mixing rules, viz. those of Arago and Biot, Newton, Heller, Gladstone and Dale, Eyring and John, Eykman, Lorentz and Lorentz, Weiner and Oster are used to predict the refractive indices of the binary liquid systems. Among all, the Weiner method (W) is in best agreement with the experimental results.

Physics and Chemistry of Liquids, 2004

Densities (ρ), speeds of sound (u), and viscosities (η) are reported for binary mixtures of 2-met... more Densities (ρ), speeds of sound (u), and viscosities (η) are reported for binary mixtures of 2-methoxyaniline with chlorinated ethane components (1,2-dichloroethane, 1,1,2-trichloroethane and 1,1,2,2-tetrachloroethane) over the entire composition range of mole fraction at T = (303.15-313.15) K and at atmospheric pressure (0.1 MPa). The excess properties: excess molar volume, excess isentropic compressibility and deviation in viscosity are calculated from the experimental density, speed of sound and viscosity. Excess properties are correlated using the Redlich-Kister polynomial equation. The excess partial molar volumes and excess partial molar isentropic compressibilities are calculated for all the binary systems throughout the composition range and at infinite dilutions. The results are analyzed in terms of electron donor-acceptor interactions leading to the formation of intermolecular complexes and hydrogen bonding between 2-methoxyaniline and chlorinated ethane molecules. The V E results are analyzed in light of the Prigogine-Flory-Patterson theory. Analysis of each of the three contributions viz. interactional, free volume and P* to V E has shown that the interactional contribution are positive for all studied systems, the free volume and P* contributions are negative for all the binary mixtures.

Indian Journal of Pure & Applied Physics, 2019

The density (ρ) and refractive indices (n ) of binary mixtures of formamide (FA) with dimethyleth... more The density (ρ) and refractive indices (n ) of binary mixtures of formamide (FA) with dimethylethanolamine (DMEA) and diethylethanolamine (DEEA) have been recorded at different temperatures for the whole composition ranges. The experimental values of density data and refractive index are used to estimate the molar refraction (R m ), reduced molar free volume (V m /R m ), molecular radii (r) and internal pressure (P int ). The deviations of refractive index (Δn D ), molar refractions (ΔR m ), reduced molar free volumes Δ (V m /R m ) and internal pressures (ΔP int ) have been also calculated. The variations of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions due to physical, chemical and structural effects between the unlike molecules. The applicability of different refractive index mixing rules is tested against the experimentally measured values and good agreement has been obtained.

Chemical Physics, 2013

The ultrasonic velocity (u) and density (q) of binary mixtures of 2-Chloroethanol (2-CletOH) with... more The ultrasonic velocity (u) and density (q) of binary mixtures of 2-Chloroethanol (2-CletOH) with 2-Dimethylaminoethanol (DMAE) and 2-Diethylaminoethanol (DEAE) have been measured over the entire concentration range at temperatures 293.15, 303.15 and 313.15 K. The ultrasonic velocity and density data are used to estimate adiabatic compressibility (b S), intermolecular free length (L f), molar sound velocity (R), molar compressibility (B) and specific acoustic impedance (Z) along with excess values of ultrasonic velocity (u E), adiabatic compressibility (b E S), intermolecular free length (L E f), acoustic impedance (Z E) and molar volume (V E m). The infrared spectra of both of the systems, 2-CletOH + DMAE and 2-Clet-OH + DEAE, have also been recorded at room temperature (298.15 K). The observed variations of these parameters, with concentration and temperature, are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures.

Journal of Solution Chemistry, Nov 5, 2020

Experimental refractive index, n D , data for eleven binary systems of 2-diethylethanolamine (2-D... more Experimental refractive index, n D , data for eleven binary systems of 2-diethylethanolamine (2-DEEA) + 1-propanol/1-butanol at different temperatures from T = 293.15 to 313.15 K and at atmospheric pressure, over the whole concentration range, are reported. The molar refractions (R m), molecular radii (r) , reduced molar free volumes V m ∕R m , internal pressure, P int and the deviations of refractive indices Δn D , molar refraction ΔR m , reduced molar free volumes Δ V m ∕R m , and internal pressure Δ P int were also calculated from the experimental data. Nine mixing rules, viz. those of Arago and Biot, Newton, Heller, Gladstone and Dale, Eyring and John, Eykman, Lorentz and Lorentz, Weiner and Oster are used to predict the refractive indices of the binary liquid systems. Among all, the Weiner method (W) is in best agreement with the experimental results.

Indian Journal of Pure & Applied Physics, Nov 26, 2019

The density (ρ) and refractive indices (n D) of binary mixtures of formamide (FA) with dimethylet... more The density (ρ) and refractive indices (n D) of binary mixtures of formamide (FA) with dimethylethanolamine (DMEA) and diethylethanolamine (DEEA) have been recorded at different temperatures for the whole composition ranges. The experimental values of density data and refractive index are used to estimate the molar refraction (R m), reduced molar free volume (V m /R m), molecular radii (r) and internal pressure (P int). The deviations of refractive index (Δn D), molar refractions (ΔR m), reduced molar free volumes Δ (V m /R m) and internal pressures (ΔP int) have been also calculated. The variations of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions due to physical, chemical and structural effects between the unlike molecules. The applicability of different refractive index mixing rules is tested against the experimentally measured values and good agreement has been obtained.

Journal of Molecular Liquids, Jul 1, 2016

Density (ρ) and ultrasonic velocity (μ) data of binary mixtures of formamide (FA) with 2-dimethyl... more Density (ρ) and ultrasonic velocity (μ) data of binary mixtures of formamide (FA) with 2-dimethylaminoethanol (DMAE) and 2-diethylaminoethanol (DEAE) have been measured experimentally over the whole range of compositions at 303.15, 313.15 and 323.15 K. The ultrasonic velocity and density data are used to determine adiabatic compressibility (β), intermolecular free length (L f) and specific acoustic impedance (Z) along with their excess values as V m E , u E , β S E and Z E. The IR spectra of binary mixtures formamide + 2-dimethylaminoethanol and formamide + 2-diethylaminoethanol have also been recorded at room temperature 303.15 K. The variation of these parameters with composition and temperature are discussed in terms of molecular interactions of these mixtures.

The Journal of Chemical Thermodynamics, Nov 1, 2018

Thermochimica Acta, Jun 1, 2014

The densities (ρ), ultrasonic speeds (u) and viscosities (η) are reported for binary mixtures of ... more The densities (ρ), ultrasonic speeds (u) and viscosities (η) are reported for binary mixtures of 2-methylaniline with isomeric chlorotoluenes namely o-chlorotoluene, m-chlorotoluene and p-chlorotoluene over the entire range of mole fractions at temperatures 303.15, 308.15, 313.15 and 318.15 K and at atmospheric pressure. The excess properties such as excess molar volume, excess isentropic compressibility and deviation in viscosity are calculated from the density, speed of sound and viscosity and the Redlich-Kister equation, correlates these properties. The excess partial molar properties

Thermochimica Acta, Oct 1, 2018

Highlights: 1. Hydrogen bonding occurs between FA+2-DMAE /2-DEAE molecules 2. Molecular associati... more Highlights: 1. Hydrogen bonding occurs between FA+2-DMAE /2-DEAE molecules 2. Molecular association follows: FA + 2-DEAE > FA + 2-DMAE  2 , ,), at infinite dilution, over the entire composition range are also calculated. The knowledge of the volumetric properties and molar compression aids to understand specific molecular interactions existing between the FA and 2-DMAE/ 2-DEAE molecules of the binary system. The strength of intermolecular interactions in these mixtures follows the order: FA+ 2-DEAE > FA + 2-DMAE. The required experimental data are used from our earlier work on the volumetric and acoustic study published in J. Mol. Liqs. 219 186 (2016).

Zenodo (CERN European Organization for Nuclear Research), Sep 13, 2022

Thermochimica Acta, 2018

Highlights: 1. Hydrogen bonding occurs between FA+2-DMAE /2-DEAE molecules 2. Molecular associati... more Highlights: 1. Hydrogen bonding occurs between FA+2-DMAE /2-DEAE molecules 2. Molecular association follows: FA + 2-DEAE > FA + 2-DMAE  2 , ,), at infinite dilution, over the entire composition range are also calculated. The knowledge of the volumetric properties and molar compression aids to understand specific molecular interactions existing between the FA and 2-DMAE/ 2-DEAE molecules of the binary system. The strength of intermolecular interactions in these mixtures follows the order: FA+ 2-DEAE > FA + 2-DMAE. The required experimental data are used from our earlier work on the volumetric and acoustic study published in J. Mol. Liqs. 219 186 (2016).

Physics and Chemistry of Liquids, 2020

This work reports the volumetric properties of binary mixtures of 2-dimethylaminoethanol (DMAE) a... more This work reports the volumetric properties of binary mixtures of 2-dimethylaminoethanol (DMAE) and 2-diethylaminoethanol (DEAE) with dimethylsulfoxide (DMSO) as a function of composition in the temperature range 298.15-318.15 K at atmospheric pressure. The excess molar volumes, apparent molar volumes, and excess partial molar volumes of both the components were determined in order to reflect several aggregation patterns present in the binary solvent system. The excess molar volumes show positive deviations from ideality. The excess partial molar volumes show complex dependence on composition and temperature. The results were used to investigate intermolecular interaction and structural configuration in these mixtures.

Journal of Molecular Liquids, 2016

Density (ρ) and ultrasonic velocity (μ) data of binary mixtures of formamide (FA) with 2-dimethyl... more Density (ρ) and ultrasonic velocity (μ) data of binary mixtures of formamide (FA) with 2-dimethylaminoethanol (DMAE) and 2-diethylaminoethanol (DEAE) have been measured experimentally over the whole range of compositions at 303.15, 313.15 and 323.15 K. The ultrasonic velocity and density data are used to determine adiabatic compressibility (β), intermolecular free length (L f) and specific acoustic impedance (Z) along with their excess values as V m E , u E , β S E and Z E. The IR spectra of binary mixtures formamide + 2-dimethylaminoethanol and formamide + 2-diethylaminoethanol have also been recorded at room temperature 303.15 K. The variation of these parameters with composition and temperature are discussed in terms of molecular interactions of these mixtures.

Journal of Molecular Liquids, 2015

Experimental refractive index, n D , data for eleven binary systems of 2-diethylethanolamine (2-D... more Experimental refractive index, n D , data for eleven binary systems of 2-diethylethanolamine (2-DEEA) + 1-propanol/1-butanol at different temperatures from T = 293.15 to 313.15 K and at atmospheric pressure, over the whole concentration range, are reported. The molar refractions (R m), molecular radii (r) , reduced molar free volumes V m ∕R m , internal pressure, P int and the deviations of refractive indices Δn D , molar refraction ΔR m , reduced molar free volumes Δ V m ∕R m , and internal pressure Δ P int were also calculated from the experimental data. Nine mixing rules, viz. those of Arago and Biot, Newton, Heller, Gladstone and Dale, Eyring and John, Eykman, Lorentz and Lorentz, Weiner and Oster are used to predict the refractive indices of the binary liquid systems. Among all, the Weiner method (W) is in best agreement with the experimental results.

Physics and Chemistry of Liquids, 2004

Densities (ρ), speeds of sound (u), and viscosities (η) are reported for binary mixtures of 2-met... more Densities (ρ), speeds of sound (u), and viscosities (η) are reported for binary mixtures of 2-methoxyaniline with chlorinated ethane components (1,2-dichloroethane, 1,1,2-trichloroethane and 1,1,2,2-tetrachloroethane) over the entire composition range of mole fraction at T = (303.15-313.15) K and at atmospheric pressure (0.1 MPa). The excess properties: excess molar volume, excess isentropic compressibility and deviation in viscosity are calculated from the experimental density, speed of sound and viscosity. Excess properties are correlated using the Redlich-Kister polynomial equation. The excess partial molar volumes and excess partial molar isentropic compressibilities are calculated for all the binary systems throughout the composition range and at infinite dilutions. The results are analyzed in terms of electron donor-acceptor interactions leading to the formation of intermolecular complexes and hydrogen bonding between 2-methoxyaniline and chlorinated ethane molecules. The V E results are analyzed in light of the Prigogine-Flory-Patterson theory. Analysis of each of the three contributions viz. interactional, free volume and P* to V E has shown that the interactional contribution are positive for all studied systems, the free volume and P* contributions are negative for all the binary mixtures.

Indian Journal of Pure & Applied Physics, 2019

The density (ρ) and refractive indices (n ) of binary mixtures of formamide (FA) with dimethyleth... more The density (ρ) and refractive indices (n ) of binary mixtures of formamide (FA) with dimethylethanolamine (DMEA) and diethylethanolamine (DEEA) have been recorded at different temperatures for the whole composition ranges. The experimental values of density data and refractive index are used to estimate the molar refraction (R m ), reduced molar free volume (V m /R m ), molecular radii (r) and internal pressure (P int ). The deviations of refractive index (Δn D ), molar refractions (ΔR m ), reduced molar free volumes Δ (V m /R m ) and internal pressures (ΔP int ) have been also calculated. The variations of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions due to physical, chemical and structural effects between the unlike molecules. The applicability of different refractive index mixing rules is tested against the experimentally measured values and good agreement has been obtained.

Chemical Physics, 2013

The ultrasonic velocity (u) and density (q) of binary mixtures of 2-Chloroethanol (2-CletOH) with... more The ultrasonic velocity (u) and density (q) of binary mixtures of 2-Chloroethanol (2-CletOH) with 2-Dimethylaminoethanol (DMAE) and 2-Diethylaminoethanol (DEAE) have been measured over the entire concentration range at temperatures 293.15, 303.15 and 313.15 K. The ultrasonic velocity and density data are used to estimate adiabatic compressibility (b S), intermolecular free length (L f), molar sound velocity (R), molar compressibility (B) and specific acoustic impedance (Z) along with excess values of ultrasonic velocity (u E), adiabatic compressibility (b E S), intermolecular free length (L E f), acoustic impedance (Z E) and molar volume (V E m). The infrared spectra of both of the systems, 2-CletOH + DMAE and 2-Clet-OH + DEAE, have also been recorded at room temperature (298.15 K). The observed variations of these parameters, with concentration and temperature, are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures.