Acid-dissociation constant electron-pair acceptor

Br0nsted-Lowery acids are H+ donors and bases are H+ acceptors. Strong acids dissociate completely in water. Weak acids only partially dissociate, establishing an equilibrium system. Weak acid and base dissociation constants (Ka and Kb) describe these equilibrium systems. Water is amphoteric, acting as both an acid or a base. We describe water s equilibrium by the Kw expression. A pH value is a way of representing a solution s acidity. Some salts and oxides have acid-base properties. A Lewis acid is an electron pair acceptor while a Lewis base is an electron pair donor. 

Thus, water functions both as an acid (donor of or proton) and as a base (acceptor of H+ or proton). This description of an acid and a base follows from the Bronsted-Lowry theory. According to the Lewis theory, acids are electron pair acceptors and bases are electron pair donors. The equilibrium constant, K, for the dissociation reaction in Equation (1.1) is... 

Brpnsted acids are proton donors bases are proton acceptors. Acid strength is measured by the acid dissociation constant A), pXa = —log K. Acids and their deprotonated forms have a conjugate relation. Lewis acids and bases are electron pair acceptors and donors, respectively. 

Acidic/Basic Lewis acidity/basicity determines the solvent s abihty to demate or accept a pair of electrons to form a coordinate bond with solute and/or between solvent molecules. A scale for this acid/base pre ierty was proposed by Gutman (DN and AN -donor and acceptor number, reflectively) based on caleuimetric determination. The complete proton transfer reaction with femnatiem of protonated ions is determined by proton affinity, gas phase acidity, acid or base dissociation constants. Both concepts differ in terms of net chemicsd reactiem. 

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