Solvents as Acids and Bases

The electron pair donicity and acceptance ability of solvent molecules are reflected in their bulk properties dealt with in Sections 3.3.2.2 and 3.3.2.3. They are, of course, related to their reactions as acids and bases pertaining specifically to the deproton-ation or protonation in the gas phase, on the one hand, and these reactions in dilute solutions in a reference solvent (water) on the other, as well as their autoprotolysis as pure liquids. These topics are dealt with in the present section. 

The deprotonation of gaseous molecules of protic or protogeuic solvents is measured by the standard molar Gibbs energy, AG, of the reaction SH(g) S (g) -l- H (g) where SH stands for a protic solvent molecule. It is generally compared with that of hydrogen chloride in a competitive reaction 

The protonation of gaseous solvent molecules is measured by the standard molar enthalpy, called proton affinity, PA, of the reaction S(g) + (g) - SH (g), where S 

The acid dissociation of protic or protogenic solvent molecules in dilute solution in water according to 

TABLE 3.10 The Stanflard Molar Gibbs Energy for Protonation of Gaseous Solvent Molecules Relative to HCI(g), AAG, their Proton Affinities (enthalpies) Relative to Ammonia, AM, and Differences of the Logarithmic Equilibrium Constants of Solvents in Dilute Solutions in Water for Protonation, Ap T, and Deprotonation ApA, Relative to the Autoprotofysis Constant of Water, and the Logarithmic Constants pA for Autoprotolysis of the Neat Solvents 

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