Relevance of acid-base theories to AB cements

The various acid-base definitions are summarized in the Venn diagram (Fig. 2.1). From this it can be seen that the Usanovich definition subsumes the Lewis definition, which in turn subsumes all other definitions (i.e. Arrhenius, Bronsted-Lowry, Germann-Cady-Elsey, Lux-Flood). 

Also shown is how the topic of AB cements relates to these definitions. An ideal definition for a subject should be one that exactly fits it. It should cover all aspects of the subject while excluding all extraneous topics. Thus, a theory should be neither too restrictive nor too general. The Arrhenius and Germann-Cady-Elsey definitions do not relate to the subject at all as 

From this discussion it can be seen that there is no ideal acid-base theory for AB cements and a pragmatic approach has to be adopted. Since the matrix is a salt, an AB cement can be defined quite simply as the product of the reaction of a powder and liquid component to yield a salt-like gel. The Bronsted-Lowry theory suffices to define all the bases and the protonic acids, and the Lewis theory to define the aprotic acids. The subject of acid-base balance in aluminosilicate glasses is covered by the Lux-Flood theory. 

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