Conductance Studies in Acetonitrile-Water Mixtures

1987 ◽  
Vol 42 (11) ◽  
pp. 1305-1308
Author(s):  
E. Hawlicka
Keyword(s):  
Mixed Solvent ◽  
Composition Range ◽  
Association Constants ◽  
Solvent Composition ◽  
Ionic Association ◽  
Sodium Ions

The conductance of Nal in acetonitrile-water mixtures was measured at 25.000 ± 0.001 °C for the whole composition range of the mixed solvent, the salt molarity ranging from 5 · 10-5 to 1 · 10-2 . Using the Fuoss-Hsia equation with the Fenandez-Prini parameters, the association constants were computed for several values of the ion-ion distances. The influence of the mixed solvent composition on the ionic association is discussed. An arranging effect of the sodium ions, postulated previously, is confirmed.

scholarly journals Effect of solvent composition on the critical micelle concentration of sodium deoxycholate in ethanol-water mixed solvent media

BIBECHANA ◽  
2012 ◽  
Vol 9 ◽  
pp. 63-68 ◽  
Author(s):  
Ajaya Bhattarai ◽  
Sujit Kumar Shah ◽  
Ashok Kumar Yadav ◽  
Janak Adhikari
Keyword(s):  
Critical Micelle Concentration ◽  
Precise Measurement ◽  
Mixed Solvent ◽  
Volume Fraction ◽  
Pure Water ◽  
Specific Conductivity ◽  
Sodium Deoxycholate ◽  
Solvent Composition ◽  
Effect Of Solvent

The precise measurement of the specific conductivity of sodium deoxycholate in pure water and ethanolwater mixed solvent media containing 0.10 and 0.20 volume fraction of ethanol at 303.15 K are reported. The concentration were varied from ~ 0.01 mol L-1 to ~ 0.0002 mol L-1.The conductivity of sodium deoxycholate decreases with the increase in the volume fraction of ethanol. The critical micelle concentration of sodium deoxycholate increases with the increase in the volume fraction of ethanol. DOI: http://dx.doi.org/10.3126/bibechana.v9i0.7176 BIBECHANA 9 (2013) 63-68

scholarly journals Effect of Solvent Composition on the Critical Micelle Concentration of Cetylpyridinium Chloride in Ethanol-Water Mixed Solvent Media

2013 ◽  
Vol 13 (1) ◽  
pp. 89-93 ◽  
Author(s):  
Ajaya Bhattarai ◽  
Sujit Kumar Shah ◽  
Ashok Kumar Yadav
Keyword(s):  
Critical Micelle Concentration ◽  
Room Temperature ◽  
Mixed Solvent ◽  
Volume Fraction ◽  
Science And Technology ◽  
Pure Water ◽  
Specific Conductivity ◽  
Cetylpyridinium Chloride ◽  
Solvent Composition ◽  
Effect Of Solvent

The accurate measurement of the specific conductivity of cetylpyridinium chloride in pure water and ethanol-water mixed solvent media containing 0.10, 0.20, 0.30 and 0.40 volume fraction of ethanol at room temperature are reported. The concentrations were varied from ~ 0.005 mol l-1 to ~ 0.0002 mol l-1.The conductivity of cetylpyridinium chloride decreases with the increase in the volume fraction of ethanol. The critical micelle concentration of cetylpyridinium chloride increases with the increase in the volume fraction of ethanol. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 89-93 DOI: http://dx.doi.org/10.3126/njst.v13i1.7446

Metal-Assisted Reactions. Part XXX. Control of Rates of Heterogeneously Catalyzed Transfer Hydrogenolysis through Changes in Solvent Composition

2003 ◽  
Vol 56 (5) ◽  
pp. 423 ◽  
Author(s):  
José A. C. Alves ◽  
Amadeu F. Brigas ◽  
Robert A. W. Johnstone
Keyword(s):  
Liquid Phase ◽  
Adsorption Isotherms ◽  
Mixed Solvent ◽  
Phase Transfer ◽  
Catalyst Surface ◽  
Solvent System ◽  
Solvent Composition ◽  
Phase Solubility ◽  
Mixed Solvent System ◽  
Rate Of Reaction

Adsorption isotherms in the liquid phase can be used to determine the relative strengths of adsorption of reactants and solvent at a catalyst surface. Such isotherms can then be used to indicate which type of solvent would be most suitable for a heterogeneously catalyzed reaction in the liquid-phase. Solubility in any chosen solvent is also important. As examples, rates of heterogeneously catalyzed liquid-phase transfer hydrogenolyzes of aryl tetrazolyl ethers (1) have been shown to be highly dependent on both the nature of the solvent and on the solution concentrations of the reactants. The rate of reaction can be varied from zero to a maximum and then back to zero simply by adjusting the solubility of the reductant through changes in the proportion of water in a mixed-solvent system.

The Ionization of Picric Acid in Ethanol–Sulfolane and t-Butyl Alcohol – Sulfolane Mixtures at 30 °C

1975 ◽  
Vol 53 (11) ◽  
pp. 1651-1656 ◽  
Author(s):  
Maurizio Castagnolo ◽  
Angelo De Giglio ◽  
Angelo Dell'atti ◽  
Giuseppe Petrella
Keyword(s):  
Association Constant ◽  
Composition Range ◽  
Dissociation Constants ◽  
Picric Acid ◽  
Preferential Solvation ◽  
Butyl Alcohol ◽  
Weak Acid ◽  
Solvent Composition ◽  
Solvent Mixtures ◽  
Simple Dissociation

Dissociation constants at 30 °C of picric acid have been determined by a spectrophotometric method in ethanol–sulfolane and t-butyl alcohol – sulfolane mixtures over the entire solvent composition range. Picric acid behaves as a weak acid in all mixtures. In pure sulfolane, picric acid undergoes simple dissociation for c < 0.08 M (pKHPI = 7.6). At concentrations higher than 0.08 M more complex equilibria have been observed and interpreted assuming Pi(HPi)2− as the principal picrate species in solution. Complex behavior of dependence of association constant on solvent composition was observed; in both solvent mixtures as sociation of picric acid decreases with decrease of dielectric constant. This behavior was discussed in terms of preferential solvation of picric acid by alcohols, the more basic components of the mixtures. A reaction mechanism of four alcohol molecules with one acid molecule accounts for the behavior observed.

The Conductance of Naland Tetraethylammonium Iodide in Mixtures of Methanol with Acetonitrile and Water

1991 ◽  
Vol 46 (1-2) ◽  
pp. 122-126 ◽  
Author(s):  
E. Hawlicka ◽  
R. Grabowski
Keyword(s):  
Salt Concentration ◽  
Association Constant ◽  
Ion Pairs ◽  
Solvent Composition ◽  
Ionic Association ◽  
Equivalent Conductance ◽  
Tetraethylammonium Iodide

AbstractThe conductance of Nal and Et4NI in methanol-acetonitrile and methanol-water mixtures was measured at 25 ± 0.005 °C for the whole range of the solvent compositions, the salt molarity ranging from 5 • 10-5 up to 1 • 10-2. Several equations describing the influence of the salt concentration on the equivalent conductance are examined and the Fuoss-Hsia equation with the Fernandez-Prini parameters is found to be the most appropriate one for systems with weak ionic association. Variations with the solvent composition of the limiting equivalent conductance, the distance between ions forming ion pairs and the association constant are discussed. Nonmonotonous changes of the association constant are concluded to be a feature of microheterogenous systems.

Solvation of sodium ions studied by 23Na nuclear magnetic resonance

1968 ◽  
Vol 46 (22) ◽  
pp. 3425-3430 ◽  
Author(s):  
E. G. Bloor ◽  
R. G. Kidd
Keyword(s):  
Infinite Dilution ◽  
Sodium Iodide ◽  
Mixed Solvent ◽  
Chemical Shifts ◽  
Preferential Solvation ◽  
Anomalous Behavior ◽  
Sodium Ion ◽  
Sodium Ions ◽  
Nitrogen Donor ◽  
Solvent Systems

The 23Na chemical shifts, extrapolated to infinite dilution, of solutions containing sodium iodide dissolved in 14 different oxygen or nitrogen donor organic solvents have been determined. The observed range of chemical shifts can be successfully related to changes in the paramagnetic term of the general nuclear screening equation. A fair correlation between the magnitude of the paramagnetic term and the Lewis basicity of the solvent has been drawn. Those solvents showing anomalous behavior are the ones for which large magnetic anisotropies are to be expected. The 23Na chemical shifts for two mixed solvent systems containing sodium iodide have been obtained, and these support the conclusion that preferential solvation of the sodium ion occurs.

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