The pH is often defined as the negative log of the H+ concentration. It is more appropriate to state that pH is the negative log of the activity of the H+ concentration.
ChemSource is produced by NSF to provide teachers additional support material. Each unit in ChemSource has a section set aside for common student misconceptions. Those listed for acids and bases are separated into three separate html unit that can be navigated by clicking on arrows.
Students often wonder why Mg(OH)2 is a strong base if it dissolves so poorly. A strong acid or strong base is a substance in solution that completely ionizes. When Mg(OH)2 dissolves only slightly but dissociates completely.
