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.

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.

Calculation of Darken Stability Functions of Al-In and Bi-Zn Binary Liquid Alloys

2021 ◽  
Vol 14 (2) ◽  
pp. 111-116
Keyword(s):  
Free Energy ◽  
Activity Ratio ◽  
Binary Alloys ◽  
Concentration Fluctuation ◽  
Nearest Neighbour ◽  
Stability Function ◽  
Energy Of Mixing ◽  
Neighbour Shell ◽  
Free Energy Of Mixing ◽  
The Ideal

Abstract: The thermodynamic model based on clustering of two atoms is considered with the view to obtain the concentration-concentration fluctuation, Scc(0) and the darken stability function. The thermodynamic properties of these alloys were evaluated based on clustering of two atoms (A & B) or (B & A). Each system has the view of obtaining concentration-concentration fluctuation, Scc(0) enumerating the low-order atomic correlation in the nearest neighbour shell of liquid binary alloys. The highlights of reciprocals of Scc(0) of these alloys were noted . The values of Scc(0) for Al-In alloy throughout the entire concentration were positive and higher for activity ratio and lower than the ideal solution values for free energy of mixing at specific Al composition. The values of darken stability function of Al-In alloy fall below the ideal darken stability function for activity ratio and free energy of mixing . The indication of the reciprocal of Scc(0) for all the alloys is in support of homocoordination / heterocoordination in the nearest neighbour shell. The Scc(0) and darken stability function of Bi-Zn binary alloys were noted with fluctuations. Keywords: Concentration-concentration fluctuation, Darken stability function, Ordering energy.

Activity coefficients of NaNO3 in (Mg, Ca, Sr, and Ba)(NO3)2 + H2O systems at 298 K by EMF methods

1993 ◽  
Vol 71 (3) ◽  
pp. 384-389 ◽  
Author(s):  
Stephen N. Smith ◽  
S. Sarada ◽  
Ramamurthy Palepu
Keyword(s):  
Free Energy ◽  
Ionic Strength ◽  
Gibbs Free Energy ◽  
Activity Coefficients ◽  
Interaction Parameters ◽  
Excess Gibbs Free Energy ◽  
Experimental Activity ◽  
Energy Of Mixing ◽  
Total Ionic Strength ◽  
Free Energy Of Mixing

The activity coefficients of NaNO3 in Mg(NO3)2, Ca(NO3)2, Sr(NO3)2 and Ba (NO3)2 were determined at constant total ionic strength of 0.1, 0.5, 0.75, 1.0, 1.5, and 2.0 mol kg−1 at 298 K using EMF methods. The experimental activity coefficients were analyzed using four different formalisms, namely, Reilly–Wood–Robinson, Scatchard, Pitzer, and Harned equations, and the interaction parameters were evaluated. Excess Gibbs free energy of mixing and trace activity coefficients were calculated and the results are discussed.

scholarly journals Regular Associated Solution Model for the Estimation of Free Energy of Mixing of Binary Liquid Alloys

1970 ◽  
Vol 8 (8) ◽  
pp. 30-33
Author(s):  
D Adhikari ◽  
BP Singh ◽  
IS Jha
Keyword(s):  
Free Energy ◽  
Equilibrium Constants ◽  
Solution Model ◽  
Interaction Energies ◽  
Free Energies ◽  
Scientific World ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Associated Solution Model ◽  
Associated Solution

We have found the equilibrium constants and pairwise interaction energies between the species and the complexes of liquid CuSn, AgAl, FeSi, CdNa and HgNa alloys on the basis of regular associated solution model. These parameters are then used to estimate the free energies of mixing of each alloy. The observed asymmetry in the free energy of mixing of each alloy with respect to concentration is well explained. Key Words: Free energy of mixing; Asymmetry; Binary alloys; Interaction energy. DOI: 10.3126/sw.v8i8.3842 Scientific World Vol.8(8) 2010 pp.30-33

Prediction of the Phase Behaviour of Hydrogen-Bonded Polymer Blends

2006 ◽  
Vol 59 (8) ◽  
pp. 499 ◽  
Author(s):  
Michael M. Coleman ◽  
Paul C. Painter
Keyword(s):  
Polymer Blends ◽  
Functional Group ◽  
Equilibrium Constants ◽  
Phase Behaviour ◽  
Low Molecular Weight ◽  
Full Circle ◽  
Energy Of Mixing ◽  
The Subject ◽  
Free Energy Of Mixing ◽  
Hydrogen Bonded

In the early 1990s your authors believed that they had essentially solved the problem of predicting the phase behaviour of hydrogen-bonded polymer blends. A text devoted to this subject, Specific Interactions and the Miscibility of Polymer Blends, was published and we thought that it was now time to look around for something else to do. This was before a colleague, Boris Veytsman, pointed out that there was a flaw in our derivation of the free energy of mixing equation. It has taken us some 15 years to correct the theory and match the predictions of the phase behaviour of hydrogen-bonded blends that we presented in our 1991 book. So we have come full circle. The subject has become far more complicated, but at the same time far more interesting. Along the way we have discovered that the phase behaviour of hydrogen-bonded polymer blends can be successfully predicted using equilibrium constants determined from appropriate low molecular weight analogues, if chain connectivity effects such as intermolecular screening and functional group accessibility are included.

scholarly journals Thermodynamic, structural, surface and transport properties of Au-Ni liquid alloy at 1150 K

BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 184-192
Author(s):  
S K Yadav ◽  
N Chaudhary ◽  
D Adhikari
Keyword(s):  
Free Energy ◽  
Transport Properties ◽  
Gibbs Free Energy ◽  
Liquid Alloy ◽  
Concentration Fluctuation ◽  
Excess Gibbs Free Energy ◽  
Long Wavelength ◽  
Energy Of Mixing ◽  
Structural Surface ◽  
Free Energy Of Mixing

Thermodynamic, structural, surface, and transport properties of Au-Ni liquid alloy at 1150 K were computed using different theoretical approaches. The thermodynamic properties, such as excess Gibbs free energy of mixing, enthalpy of mixing, activity and excess entropy of mixing, and structural properties, such as concentration fluctuation in long-wavelength limit and Warren-Cowley short-range order parameter were computed in the framework of Flory’s model. The effect of positive and negative values of the interchange energy parameter on the excess Gibbs free energy of mixing and concentration fluctuation in the long-wavelength limit was also observed. The surface tension and surface concentration of the system were calculated using Butler’s model. In the transport property, the viscosity of the system was calculated using Kaptay and Budai-Benko-Kaptay (BBK) models. BIBECHANA 18 (2021) 184-192

Sign in / Sign up

Export Citation Format

Share Document