3b1 Acids and bases

The Lowry-Bronsted theory of acids and bases depends on the giving and receiving of hydrated hydrogen ions.

An H⁺ ion is a hydrogen atom that has lost an electron.
Since a hydrogen atom is only made of one proton and one electron, if it loses one electron it is just a proton!
This very small particle with a full positive charge is strongly attracted to water molecules and so we ought to talk of the “hydrated hydrogen ion” or the “hydrated proton”...H⁺_(aq) or H₃O⁺_(aq). 

All acids have at least one hydrogen atom in them that can be released as a hydrated hydrogen ion. The releasable hydrogen ion is shown in these examples in bold type
eg hydrochloric acid (HCl), sulfuric acid (H₂SO₄), ethanoic acid (CH₃COOH)

All bases have the ability to accept a hydrated hydrogen ion.
eg Sodium hydroxide contains OH^- which can accept a hydrated hydrogen ion to form water. Ammonia (NH₃) can gain a hydrated hydrogen ion to form ammonium (NH₄⁺).

A base that is soluble in water is called an alkali.