Ionization constants of acids

A. Albert ajid E. P. Serjeant, Ionization Constants of Acids ajid Bases, pp. 140 f. Methuen, London, 1962. 

The cosolvent will lower the dielectric constant of the mixed solvent, independent of the properties of the solute molecule. The ionization constant of acids will increase and that of bases will decrease (see Sections 3.3.3 and 3.3.4), the result of which is to increase the fraction of uncharged substance in... 

Albert, A. and Serjeant, E.P. (1962) Ionization Constants of Acids Bases. A Laboratory Manual... 

Albert, A. Sergeant, E. P., Ionization Constants of Acids and Bases, Wiley, New York, 1962. 

Figure 5. Ionization constants of acids in various solvents vs. the dielectric constant function at 25°C. A,B,C ethanol-water (O), methanol-water (A), dioxane-water ( ). B,C acetone-water ( ), glycerol-water (W). B 2-methoxyethanol-water (V), dimethyl-sulfoxide-water (M).

In capillary electrophoresis (CE), several criteria can be applied to classify solvents [e.g., for practical purposes based on the solution ability for analytes, on ultraviolet (UV) absorbance (for suitability to the UV detector), toxicity, etc.]. Another parameter could be the viscosity of the solvent, a property that influences the mobilities of analytes and that of the electro-osmotic flow (EOF) and restricts handling of the background electrolyte (BGE). For more fundamental reasons, the dielectric constant (the relative permittivity) is a well-recognized parameter for classification. It was initially considered to interpret the change of ionization constants of acids and bases according to Born s approach. This approach has lost importance in this respect because it is based on too simple assumptions limited to electrostatic interactions. Indeed, a more appropriate concept reflects solvation effects, the ability for H-bonding, or the acido-base property of the solvent. 

Usually, when determining the ionization constants of acid-base groups on surface a use is made of not this equation but of the Henderson Hasselbalch equation ... 

Table VIII. Thermodynamic Ionization Constants of Acids at 25° from Conductance Measurements...

THE RELATIONSHIP BETWEEN THE IONIZATION CONSTANTS OF ACIDS AND THEIR CONJUGATE BASES... 

Of substances derived from the structure CRR CRR a large number of isomers are known, of which maleic and fumaric acids may serve as examples. From what has been said, the more stable, fumaric acid, may be assigned the formula CRR lCRR, the less stable, maleic acid, the formula CRR I CRR. These structures agree with the structures developed from the ionization constants of acids. 

Albert A, Serjeant EP. The Determination of Ionization Constants of Acids and Bases A Laboratory Manual. 3rd Ed. New York, Chapman and Hall, 1984. 

Electron Configurations of the Elements Ionization Constants of Acids and Bases Reduction Potentials Solubility Products Thermodynamic Data Vapor Pressures of Water... 

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