Acids and bases definitions (Arrhenius, Bronsted and Lewis)
Arrhenius defined acid as a hydrogen compound which in water solution give hydrogen ions.
He defined base as a hydroxide compound which in water solution gives hydroxide ions.
Lowry and Bronsted
An acid is defined as a substance having a tendency of lose or to donate one or more protons.
A base is defined as a substance having a tendency to accept or add a proton
Lewis Theory of Acids and Bases
Acid: An acid is any substance (molecule, ion or atom) that can accept a lone pair of electrons to form a coordinate bond (*Remember coordinate bond and lone pair topics in chapter on Bonding)
Base: Base is any species (molecule, ion or atom) that can donate a lone pair of electrons to form a co-ordinate bond.