Ionization constant of acids and bases

A. Albert and E. P. Serjeant, Ionization Constants of Acids and Bases. Methuen, London, 1962. 

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. 

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... 

The static headspace technique is very simple and quick. The procedure is well documented in the literature, and for many applications the sensitivity is more than adequate, so that its use is usually favoured over that of the P8dT technique. There are areas of application where good results are obtained with the static headspace technique which cannot be improved upon by the P8dT method. These include the forensic determination of alcohol in blood, of free fatty acids in cell cultures, of ethanol in fermentation units or drinks and residual water in polymers. This also applies to studies on the determination of ionization constants of acids and bases and the investigation of gas phase equilibria. 

A weak acid or base has a small ionization constant or Ky is much less than 1. For a weak acid or base, the corresponding ionization reaction occurs to a limited extent, with a significant fraction of the acid or base not ionized. To determine the equilibrium composition of a solution of a weak acid or weak base, we need to solve an equilibrium problem, typically by using an ICE table and the value of the appropriate ionization constant, or K. Ionization constants of some weak acids and weak bases are provided in Table 16.4. A more extensive list is given in Appendix D. Ionization constants of acids and bases are determined by experiment. 

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