Activity Ratios of Lyate Ions in the Water-Alcohol Mixtures

1992 ◽  
Vol 57 (2) ◽  
pp. 255-262
Author(s):  
Zdeněk Pavelek ◽  
Jiří Mollin
Keyword(s):  
Experimental Determination ◽  
Activity Ratio ◽  
Mixed Solvents ◽  
Ion Transfer ◽  
Gibbs Energies ◽  
Activity Ratios ◽  
Alcohol Mixtures ◽  
The Individual ◽  
Water Alcohol

A new method for calculating the activity ratio of lyate ions in the water-alcohol mixtures is proposed on the basis of utilizing the linear relations between the Gibbs energies of ion transfer. The results for the water-methanol, -ethanol, and -2-propanol systems are compared with literature data. At the same time, the individual ionic products of water and alcohol in their mixtures were calculated. The accuracy of the method depends on the accuracy of experimental determination of the Gibbs energies of electrolyte transfer and of ionic products in mixed solvents.

Autoprotolysis constants and activity ratios of the lyate ions in water-alcohol mixtures

1983 ◽  
Vol 48 (8) ◽  
pp. 2156-2164 ◽  
Author(s):  
Jiří Mollin ◽  
Zdeněk Pavelek ◽  
Alena Schneiderová ◽  
Jaroslav Vičar ◽  
Vilím Šimánek ◽  
...  
Keyword(s):  
Mixed Solvent ◽  
Empirical Method ◽  
Ionization Constants ◽  
Ion Transfer ◽  
H Nmr ◽  
Gibbs Energies ◽  
Nmr Data ◽  
Activity Ratios ◽  
Ethanol System ◽  
Water Alcohol

The autoprotolysis constants were determined potentiometrically for water-ethanol, water-1-propanol, water-2-propanol, and water-2-methyl-2-propanol mixtures containing alcohol in concentrations of 60% (m/m) and more. Three methods were employed for the calculation of the activity ratios of the lyate ions in the systems: an empirical method based on the autoprotolysis constant and the activities of the solvent constituents, a method based on thermodynamic data, particularly the Gibbs energies of ion transfer from water to the mixed solvent, and a method based on 1H NMR data. The results of the three methods are mutually compared and discussed. The known heats of ionization for the water-ethanol system and the ionization constants of the components enabled the entropy of ionization of a mixture of water with ethanol to be calculated.

ANALYSIS OF THE COMPOSITION OF WATER-ALCOHOL MIXTURES USING THE INFRARED ABSORPTION SPECTRA OF THEIR VAPORS

2021 ◽  
Vol 88 (6) ◽  
pp. 933-941
Author(s):  
V. L. Vesnin
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Absorption Spectra ◽  
Infrared Absorption ◽  
Liquid Mixture ◽  
The Mean ◽  
Alcohol Mixtures ◽  
Infrared Absorption Spectra ◽  
Water Alcohol

The article presents the results of studies of infrared absorption spectra of saturated vapors of alcohols and alcohol-containing mixtures in the range of 1.3—1.5 μm. A method was developed for the quantitative determination of the composition of water-alcohol mixtures based on the use of multiple linear regression, and a range of methanol concentrations was determined, in which the nonlinearity of the dependence of the concentration of alcohols in saturated vapors over a liquid mixture on the concentration of alcohols in this liquid mixture does not significantly affect the results of analysis of the mixture composition. A method for optimizing a set of wavelengths for multiple linear regression, based on minimizing the mean-square error in determining the concentration is proposed and implemented. The developed methods make it possible to determine the presence of small (<1%) amounts of methanol against the background of large amounts of ethanol and water using relatively inexpensive and accessible spectroscopic equipment.

scholarly journals The behaviour of electrolytes in mixed solvents. Part V.–The free energy of lithium chloride in water-alcohol mixtures and the salting-out of alcohol

1933 ◽  
Vol 141 (843) ◽  
pp. 86-94 ◽  
Keyword(s):  
Partial Pressure ◽  
Lithium Chloride ◽  
Mixed Solvents ◽  
Salting Out ◽  
Partial Pressures ◽  
All Solutions ◽  
The Mean ◽  
Alcohol Mixtures ◽  
Solvent Molecules ◽  
Water Alcohol

In Part II of this series of papers are recorded measurements of the partial vapour pressures of solutions of lithium chloride in water-ethyl alcohol mixtures, the alcohol contents of which extended from 6•4 to 100 mols. per cent. It has seemed desirable to extend this range so as to include some smaller concentra­tions of alcohol, and accordingly measurements have now been made of solutions containing 2 and 4 mols. per cent, of alcohol and in each case 0.5, 1.0 and 4.0 m. lithium chloride. The experimental method was the same as that previously described, except that in these cases the viscosity method was less suitable for determining the composition of the condensate, which was obtained by comparison with known compositions in the interferometer. The final values of the partial pressures, each being the mean of at least two deter­minations, are given in Table I. α w /α w 0 and α a /α a 0 are the relative activities, i. e ., the ratio of the partial pressure in a given solution to the partial pressure of the corresponding solvent. Two of the solutions containing 6.4 mols. per cent, alcohol were also redetermined and gave values in close agreement with those previously obtained. We are now in a position to discuss in more detail the behaviour of these solutions. It was shown in the previous paper that while the salt increased the partial pressure of alcohol in solutions containing smaller proportions of alcohol, it caused a lowering of the pressure in the more alcoholic solutions, but the relative lowering of the vapour pressure of alcohol was always less than that of water, indicating that in all solutions the alcohol was salted out with respect to the water. In order to assess this effect more precisely it is necessary to consider what will be the behaviour of a solute which interacts equally with the two solvent molecules.

Determination of Intraparticle Diffusivities of Na+/K+in Water and Water/Alcohol Mixed Solvents on a Strong Acid Cation Exchanger

2002 ◽  
Vol 41 (12) ◽  
pp. 3019-3027 ◽  
Author(s):  
Juan F. Rodríguez ◽  
Antonio de Lucas ◽  
Jose R. Leal ◽  
Jose L. Valverde
Keyword(s):  
Cation Exchanger ◽  
Mixed Solvents ◽  
Strong Acid ◽  
Acid Cation ◽  
Water Alcohol
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