Weak base
In chemistry, a weak base is a chemical base that does not ionize fully in an aqueous solution. This results in a relatively low pH level.
Weak bases exist in equillibrium much in the same way as weak acids do, with a Base Ionization Constant (Kb) indicating the strength of the base. For example, when ammonia is put in water, the following equillibrium sets up:
NH3 + H2O ↔ NH4+ + OH- Kb = [OH-][NH4+]/[NH3] Bases that have a large Kb will ionize more completely and are thus stronger bases. The pH of the solution depends on the OH- concentration, which is related to H+ concentration by the Ionic Constant of water (Kw = 1.0x10-14) (See article Self-ionization of water
ExamplesPyridine, C5H5NMagnesium Hydroxide, Mg(OH)2Ammonia, NH3
|
|
