Skill 16.5 Analyzing the process of dissociation in solution

A few equilibrium constants are used often enough to have their own unique nomenclature. 

The solubility-product constant, Ksp, is the equilibrium constant for an ionic solid in contact with a saturated aqueous solution. The two processes with equal rates in this case are dissolution and crystallization. 

Because this is an example of a heterogeneous equilibrium, the concentration of pure solid is not included as a variable. Ksp is a different quantity from solubility. Ksp is an equilibrium constant, and solubility is the mass of solid that is able to dissolve in a given quantity of water. 

Example Solid lead chloride PbCb is allowed to dissolve in pure water until equilibrium has been reached and the solution is saturated. The concentration of Pb is 0.016 M. What is / sp for PbCb  

The acid-dissociation constant. Kg, is the equilibrium constant for the ionization of a weak acid to a hydrogen ion and its conjugate base. 

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