Volumetric properties of, and ion-pairing in, aqueous solutions of alkali-metal sulfates under superambient conditions

1996 ◽  
Vol 92 (22) ◽  
pp. 4445-4451 ◽  
Author(s):  
Marek Obšil ◽  
Vladimír Majer ◽  
Jean-Pierre E. Grolier ◽  
Glenn T. Hefter
Keyword(s):  
Alkali Metal ◽  
Aqueous Solutions ◽  
Ion Pairing ◽  
Volumetric Properties

Raman Spectroscopic Study of Ion Pairing of Alkali Metal Ions with Carbonate and Sulfate in Aqueous Solutions

2000 ◽  
Vol 53 (10) ◽  
pp. 887 ◽  
Author(s):  
Pal Sipos ◽  
Lee Bolden ◽  
Glenn Hefter ◽  
Peter M. May
Keyword(s):  
Alkali Metal ◽  
Aqueous Solutions ◽  
Ion Pairing ◽  
Electrolyte Solutions ◽  
Ionic Interactions ◽  
Alkali Metal Ions ◽  
Sulfate Ions ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Stretching Vibrations

Raman spectra of carbonate and sulfate ions were recorded in aqueous solutions in the presence of large excesses of M′X (M′+ = Na+, K+ or Cs+; X– = OH– or Cl–) at 25°C. The positions of the v1(A1′) symmetric stretching vibrations for both CO32– (at ~1060 cm–1) and SO42– (at ~980 cm–1) shift, by up to 10 cm–1, to lower frequencies and broaden (by up to 25%) with increasing concentrations of M′X. The shifts are slightly smaller for SO42– than for CO32– and also differ somewhat between M′OH and M′Cl solutions. The changes in the peak positions, which are indicative of contact ion pairing, show a clear dependence on the nature of the cation. However, the observed order, Na+ < K+ < Cs+, is directly opposite to the magnitudes of the (overall) ion-pairing constants. This anomaly is thought to be due to decreased hydration of Cs+ cf. Na+ in these highly concentrated, water-deficient solutions. Some implications of this for understanding ionic interactions in concentrated electrolyte solutions are suggested.

Ion-pairing in aqueous solutions of peroxodisulfates

2012 ◽  
Vol 5 (2) ◽  
pp. 180-185
Author(s):  
Jan Balej
Keyword(s):  
Alkali Metal ◽  
Aqueous Solutions ◽  
Binary Solution ◽  
Ion Association ◽  
Ion Pairing ◽  
Sodium Potassium ◽  
Physico Chemical ◽  
Common Ion ◽  
Chemical Behaviour ◽  
The Common

Abstract Probable values of the degree of ion-pairing (ion-association) of aqueous solutions of alkali metal and ammonium peroxodisulfates have been calculated for various estimated values of association constants, in dependence a) on the concentration of the binary solution, b) on the concentration of the other electrolyte in the polycomponent solution with the common ion, able or not able to form ion pair, and c) on the value of the activity quotient Qa. It followed that in the presence of another component with a common cation and neglecting the influence of activity coefficients, the ion-association degree of peroxodisulfate α > 0.5 in solutions with total molality mt > 0.1 mol kg-1; as mostly Qa < 1.0, the ion-association degree is even higher so that in such cases the alkali metal and ammonium peroxodisulfates can prevailingly behave as uni-univalent electrolytes. In agreement with these results, evaluation of the solubility of sodium, potassium and ammonium peroxodisulfates in some ternary and quaternary systems has been performed under the simplified assumption of a complete ion-association to MS2O81- ions. It has been shown that the mean deviations between the calculated and observed solubilities of the crystallizing components are almost equally low as under the assumption of a total dissociation of the corresponding substances. The results indicated that the prevailing ion-association of more concentrated solutions of peroxodisufates could be taken as an acceptable approach for the quantitative evaluation of physico-chemical behaviour of systems containing peroxodisulfates.

Volumetric properties of aqueous solutions of glutaric acid

2007 ◽  
Vol 39 (7) ◽  
pp. 1071-1076 ◽  
Author(s):  
Meyrav Ben-Hamo ◽  
Alexander Apelblat ◽  
Emanuel Manzurola
Keyword(s):  
Aqueous Solutions ◽  
Glutaric Acid ◽  
Volumetric Properties
Sign in / Sign up

Export Citation Format

Share Document