Thermodynamics of molecular interactions in aniline + benzene mixtures

1979 ◽  
Vol 57 (17) ◽  
pp. 2211-2216 ◽  
Author(s):  
Ram K. Nigam ◽  
Prem P. Singh ◽  
Krishan C. Singh
Keyword(s):  
Molecular Interactions ◽  
Molecular Species ◽  
Composition Range ◽  
Equilibrium Constants ◽  
Electrolyte Solutions ◽  
General Behaviour ◽  
Heats Of Mixing ◽  
The Enthalpy Of Formation ◽  
The Ideal ◽  
Model Approach

Heats of mixing, HE, of aniline + benzene at 298.15 and 308.15 K have been measured over the entire composition range. The results have been analysed in terms of Barker's and ideal associated model theory of non-electrolyte solutions. It has been observed that the ideal associated model approach which assumes the presence of AB, AB2, A2B2, and B molecular species well describes (within ± 120 J/mol at the worst) the general behaviour of HE with xB (mole fraction of aniline) over the whole composition range for aniline + benzene mixtures. The equilibrium constants for the various association reactions along with the enthalpy of formation of various molecular species have also been calculated.

Thermodynamics of chloroform and methanol mixtures

1979 ◽  
Vol 57 (4) ◽  
pp. 387-393 ◽  
Author(s):  
Prem P. Singh ◽  
Buta R. Sharma ◽  
Kuljit S. Sidhu
Keyword(s):  
Molecular Species ◽  
Equilibrium Constants ◽  
Electrolyte Solutions ◽  
Excess Gibbs Free Energy ◽  
General Behaviour ◽  
Heats Of Mixing ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
The Enthalpy Of Formation ◽  
The Ideal

Heats of mixing and vapour pressures of chloroform (A)+ methanol (Bn) as a function of concentration have been determined at 303.15 K. The excess Gibbs free energy of mixing, GE values, have been obtained from the measured vapour pressure data. The heats of mixing values are negative for solutions rich in methanol but they become positive for solutions rich in chloroform. On the other hand, GE values are positive for all the methanol mole fractions and GE > HE. The results have been analysed in terms of Barker and ideal associated model theory of non-electrolyte solutions. The analysis has revealed that only the ideal associated model approach (which here assumes the presence of AmB (m = 1, 2), ABk (k = 2) and Bl (l = 1) molecular species) well describes the general behaviour of HE with xA over the entire chloroform concentration range for this mixture. The equilibrium constants for the various association reactions along with the enthalpy of formation of the various molecular species have also been calculated.

scholarly journals NmrLineGuru: Standalone and User-Friendly GUIs for Fast 1D NMR Lineshape Simulation and Analysis of Multi-State Equilibrium Binding Models

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chao Feng ◽  
Evgenii L. Kovrigin ◽  
Carol Beth Post
Keyword(s):  
Kinetic Model ◽  
Molecular Interactions ◽  
Rate Constants ◽  
Nmr Spectra ◽  
Equilibrium Constants ◽  
Software Tool ◽  
Biological Interactions ◽  
Equilibrium Binding ◽  
Accurate Quantitative Analysis ◽  
User Friendly

Abstract The ability of high-resolution NMR spectroscopy to readout the response of molecular interactions at multiple atomic sites presents a unique capability to define thermodynamic equilibrium constants and kinetic rate constants for complex, multiple-step biological interactions. Nonetheless, the extraction of the relevant equilibrium binding and rate constants requires the appropriate analysis of not only a readout that follows the equilibrium concentrations of typical binding titration curves, but also the lineshapes of NMR spectra. To best take advantage of NMR data for characterizing molecular interactions, we developed NmrLineGuru, a software tool with a user-friendly graphical user interface (GUI) to model two-state, three-state, and four-state binding processes. Application of NmrLineGuru is through stand-alone GUIs, with no dependency on other software and no scripted input. NMR spectra can be fitted or simulated starting with user-specified input parameters and a chosen kinetic model. The ability to both simulate and fit NMR spectra provides the user the opportunity to not only determine the binding parameters that best reproduce the measured NMR spectra for the selected kinetic model, but to also query the possibility that alternative models agree with the data. NmrLineGuru is shown to provide an accurate, quantitative analysis of complex molecular interactions.

Heats of mixing. II. Acetonitrile and nitromethane systems

1956 ◽  
Vol 9 (2) ◽  
pp. 180 ◽  
Author(s):  
I Brown ◽  
W Fock
Keyword(s):  
Free Energy ◽  
Carbon Tetrachloride ◽  
Composition Range ◽  
Excess Entropy ◽  
Excess Free Energy ◽  
Energy Data ◽  
Entropy Of Mixing ◽  
Heats Of Mixing

The heats of mixing at 45.00 �C have been measured at intervals over the whole composition range for the systems : acetonitrile+carbon tetrachloride, acetonitrile+benzene, acetonitrile +nitromethane, nitromethane + carbon tetrachloride, and nitromethane+benzene. These data, together with the excess free energy data of Brown and Smith (1954, 1955a, 1955b), have been used to calculate the excess entropy of mixing for these systems.

Thermodynamics of aqueous EDTA systems: Apparent and partial molar heat capacities and volumes of aqueous EDTA4−, HEDTA3−, H2EDTA2−, NaEDTA3−, and KEDTA3− at 25 °C. Relaxation effects in mixed aqueous electrolyte solutions and calculations of temperature dependent equilibrium constants

1988 ◽  
Vol 66 (4) ◽  
pp. 881-896 ◽  
Author(s):  
Jamey K. Hovey ◽  
Loren G. Hepler ◽  
Peter R. Tremaine
Keyword(s):  
Equilibrium Constants ◽  
Interaction Model ◽  
Electrolyte Solutions ◽  
Heat Capacities ◽  
Mixed Electrolytes ◽  
Temperature Dependent ◽  
Apparent Molar Heat Capacities ◽  
Partial Molar Heat Capacities ◽  
Relaxation Effects ◽  
Young's Rule

Calorimetric and densimetric measurements have led to apparent molar heat capacities and volumes for aqueous solutions of the mixed electrolytes [(CH3)4N]4EDTA + (CH3)4NOH, Na4EDTA + NaOH, and K4EDTA + KOH, and single electrolytes Na2H2EDTA and [(CH3)4N]3[HEDTA] at 25 °C. We have analyzed these results in terms of Young's rule and Pitzer's ion interaction model to obtain standard state partial molar heat capacities and volumes of EDTA4−(aq), HEDTA3−(aq), H2EDTA2−(aq), NaEDTA3−(aq), and KEDTA3−(aq) at 25 °C. For these calculations it was also necessary to evaluate the "relaxation" contribution to the measured heat capacities of some solutions. The partial molar heat capacities obtained here have been used with enthalpies from previous investigations for calculations of several equilibrium constants over wide ranges of temperature; volumes can be used for similar calculations of the effects of pressure.

scholarly journals Thermodynamic properties of 1-ethyl-3-methylimidazolium ethyl sulphate with nitrogen and sulphur compounds at T = (298.15 - 318.15) K and P = 1 bar

2016 ◽  
Author(s):  
◽  
Siyanda Brian Chule
Keyword(s):  
Refractive Index ◽  
Thermodynamic Properties ◽  
Binary Mixture ◽  
Binary Mixtures ◽  
Mole Fraction ◽  
Ethyl Acetoacetate ◽  
Binary Systems ◽  
Composition Range ◽  
Molar Refraction ◽  
The Ideal

In this work, the thermodynamic properties for the binary mixtures containing the ionic liquid (IL): 1-ethyl-3-methylimidazolium ethyl sulphate ([EMIM] [EtSO4]) were calculated. The binary systems studied were {pyridine (Py) or ethyl acetoacetate (EAA) or thiophene (TS) + [EMIM] [EtSO4]}. The results were interpreted in terms of the intermolecular interactions between the (pyridine + IL), (ethyl acetoacetate + IL), and (thiophene + IL) molecules. The physical properties: density, speed of sound, and refractive index were measured for the binary mixtures over the complete mole fraction range using an Anton Paar DSA 5000 M vibrating U- tube densimeter and an Anton Paar RXA 156 refractometer, respectively. The measurements were done at T = (298.15, 303.15, 308.15, 313.15, and 318.15) K and at p = 0.1 MPa. The experimental data was used to calculate the derived properties for the binary mixtures namely:- excess molar volume (V E ), isentropic compressibility (ks), molar refractions (R) and deviation in refractive index (Δn). For the binary mixtures, (Py or EAA or TS + IL), V E was negative throughout the whole composition range which indicates the existence of attractive intermolecular interaction between (pyridine + IL) and (ethyl acetoacetate + IL) for (thiophene + IL), V E was negative at low mole fraction of thiophene and became positive at high mole fraction of thiophene. For the binary mixtures (pyridine + IL), (ethyl acetoacetate + IL), ks was positive indicating that the binary mixtures were more compressible than the ideal mixture. For the binary mixture (thiophene + IL) ks was negative at low thiophene composition and positive at high composition indicating that the binary mixture was less compressible than the ideal mixture at low thiophene composition and more compressible at high composition of thiophene. The molar refraction, R, is positive for the (Py or EAA or TS + IL) binary systems at T = (298.15 – 318.15) K, molar refraction decreases as the organic solvent composition increases. For the binary mixture (pyridine + [EMIM] [EtSO4]), Δn is negative at mole fractions < 0.75 of pyridine and positive at mole fractions >0.75 at all temperatures and decreases with an increase in temperature. For the binary system (ethyl acetoacetate + [EMIM] [EtSO4]), Δn values are positive over the entire composition range and at all temperatures and increases with an increase in temperature. Δn values for the (thiophene + IL) system are negative for mole fractions of thiophene < 0.62 and becomes positive for mole fractions of thiophene > 0.62 and Δn increases with an increase in temperature. The Redlich-Kister smoothing equation was used successfully for the correlation of V E and Δn data. The Lorentz- Lorenz equation gave a poor prediction of V E , but a good prediction of density or refractive index.

scholarly journals Molecular ping-pong Game of Life on a two-dimensional DNA origami array

2015 ◽  
Vol 373 (2046) ◽  
pp. 20140215 ◽  
Author(s):  
N. Jonoska ◽  
N. C. Seeman
Keyword(s):  
Cellular Automata ◽  
Molecular Interactions ◽  
Molecular Species ◽  
Environmental Control ◽  
Dna Origami ◽  
Two Dimensional ◽  
Laser Illumination ◽  
Game Of Life ◽  
Array Platform ◽  
Ping Pong

We propose a design for programmed molecular interactions that continuously change molecular arrangements in a predesigned manner. We introduce a model where environmental control through laser illumination allows platform attachment/detachment oscillations between two floating molecular species. The platform is a two-dimensional DNA origami array of tiles decorated with strands that provide both, the floating molecular tiles to attach and to pass communicating signals to neighbouring array tiles. In particular, we show how algorithmic molecular interactions can control cyclic molecular arrangements by exhibiting a system that can simulate the dynamics similar to two-dimensional cellular automata on a DNA origami array platform.

Heats of mixing of polyelectrolyte and simple electrolyte solutions

1980 ◽  
Vol 84 (20) ◽  
pp. 2584-2587 ◽  
Author(s):  
J. Skerjanc ◽  
A. Regent ◽  
L. Bozovic Kocijan
Keyword(s):  
Electrolyte Solutions ◽  
Heats Of Mixing

scholarly journals Viskosität des flüssigen Systems Chlorbenzol + Brombenzol

1975 ◽  
Vol 30 (6-7) ◽  
pp. 916-917 ◽  
Author(s):  
R. Haase ◽  
M. Lethen ◽  
K.-H. Dücker
Keyword(s):  
Temperature Dependence ◽  
Molar Volume ◽  
Composition Range ◽  
Ideal Liquid ◽  
Liquid System ◽  
The Ideal

Abstract Results of measurements of the viscosity and of the molar volume for the ideal liquid system chlorobenzene + bromo-benzene are presented. They cover the whole composition range between 0 °C and 80 °C. Both the composition and the temperature dependence of the viscosity are discussed.

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