The viscosity of concentrated electrolyte solutions. II. Temperature dependence

1978 ◽  
Vol 56 (10) ◽  
pp. 1442-1450 ◽  
Author(s):  
Douglas E. Goldsack ◽  
Raymond C. Franchetto
Keyword(s):  
Free Energy ◽  
Temperature Dependence ◽  
Activation Parameters ◽  
Electrolyte Solutions ◽  
Hydration Numbers ◽  
Ionic Radii ◽  
Free Energy Of Activation ◽  
Halide Salts ◽  
Ionic Volume ◽  
Structure Breaking

The temperature dependence of the viscosity of concentrated aqueous electrolyte solutions has been explained in terms of the temperature dependence of the E and V parameters of an equation previously developed for the viscosity of such solutions. Analysis of the V parameters for the alkali halide and ammonium halide salts leads to absolute ionic hydration numbers. The temperature dependence of these hydration numbers reveals two types of ionic behaviour: structure making ions and structure breaking ions. The Gourary–Adrian scale of ionic radii is found to be more consistent with these data and the temperature dependence than the Pauling ionic radii scale.Analysis of the E parameters leads to the ionic free energy of activation parameters for viscous flow of the ions. The Furth model for hole formation in a liquid is found to correlate these ionic free energy values with the absolute ionic volume parameters obtained from the analysis of the V parameter for all salts. Again the ions are found to break into structure making and structure breaking groups in terms of the surface tension values for the water about the hydrated ions.

Free Energy Barrier to Rotation of the Amino Group in 2-Aminoacetophenone

1971 ◽  
Vol 49 (21) ◽  
pp. 3575-3576 ◽  
Author(s):  
R. Wasylishen ◽  
T. Schaefer
Keyword(s):  
Free Energy ◽  
Accurate Determination ◽  
Activation Parameters ◽  
Spin Coupling ◽  
Molecular Orbital Calculations ◽  
Free Energy Barrier ◽  
Amino Group ◽  
Hindered Rotation ◽  
Free Energy Of Activation ◽  
Spin Spin Coupling

The free energy of activation for hindered rotation of the amino group about the N-aryl bond in 2-aminoacetophenone is found to be 10.6 ± 0.5 kcal/mol in toluene solution at 233 ± 10 °K. Separate amino p.m.r. peaks are observed at low temperatures and these are strongly broadened by incompletely relaxed spin–spin coupling to the quadrupolar 14N nucleus, making a more accurate determination of activation parameters impractical. Some INDO molecular orbital calculations are performed in an attempt to rationalize the barrier magnitude.

Viscosity of Dimethyl Sulfoxide + 1,4 Dimethylbenzene System

2008 ◽  
Vol 59 (1) ◽  
pp. 45-48
Author(s):  
Oana Ciocirlan ◽  
Olga Iulian
Keyword(s):  
Free Energy ◽  
Dimethyl Sulfoxide ◽  
Atmospheric Pressure ◽  
Entire Range ◽  
Polynomial Equation ◽  
Energy Of Activation ◽  
Excess Gibbs Free Energy ◽  
Experimental Measurements ◽  
Gibbs Energy Of Activation ◽  
Free Energy Of Activation

This paper reports the viscosities measurements for the binary system dimethyl sulfoxide + 1,4-dimethylbenzene over the entire range of mole fraction at 298.15, 303.15, 313.15 and 323.15 K and atmospheric pressure. The experimental viscosities were correlated with the equations of Grunberg-Nissan, Katti-Chaudhri, Hind, Soliman and McAllister; the adjustable binary parameters have been obtained. The excess Gibbs energy of activation of viscous flow (G*E) has been calculated from the experimental measurements and the results were fitted to Redlich-Kister polynomial equation. The obtained negative excess Gibbs free energy of activation and negative Grunberg-Nissan interaction parameter are discussed in structural and interactional terms.

NMR Studies of Aqueous Electrolyte Solutions. IV. Hydration Numbers of Strong Electrolytes Determined from Temperature Effects on Proton Shifts

1971 ◽  
Vol 54 (1) ◽  
pp. 178-181 ◽  
Author(s):  
Brother Ferdinand J. Vogrin ◽  
Paul S. Knapp ◽  
William L. Flint ◽  
Arthur Anton ◽  
Gerald Highberger ◽  
...  
Keyword(s):  
Temperature Effects ◽  
Aqueous Electrolyte ◽  
Electrolyte Solutions ◽  
Hydration Numbers ◽  
Nmr Studies ◽  
Aqueous Electrolyte Solutions ◽  
Strong Electrolytes

Kinetics of Ion-Pair Effect of Aquation of Bromopentaammine Cobalt(III) Complex in Different Dicarboxylate Media

2011 ◽  
Vol 324 ◽  
pp. 166-169 ◽  
Author(s):  
Farah Zeitouni ◽  
Gehan El-Subruiti ◽  
Ghassan Younes ◽  
Mohammad Amira
Keyword(s):  
Free Energy ◽  
Solvent Effect ◽  
Compensation Effect ◽  
Ion Pairing ◽  
Reaction Rates ◽  
Ion Pair ◽  
Free Energy Of Activation ◽  
Different Types ◽  
Different Temperatures ◽  
Kinetics Of

The rate of aquation of bromopentaammine cobalt(III) ion in the presence of different types of dicarboxylate solutions containing tert-butanol (40% V/V) have been measured spectrophotometrically at different temperatures (30-600°C) in the light of the effects of ion-pairing on reaction rates and mechanism. The thermodynamic and extrathermodynamic parameters of activation have been calculated and discussed in terms of solvent effect on the ion-pair aquation reaction. The free energy of activation ∆Gip* is more or less linearly varied among the studied dicarboxylate ion-pairing ligands indicating the presence of compensation effect between ∆Hip* and ∆Sip*. Comparing the kip values with respect of different buffers at 40% of ter-butanol is introduced.

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