Strong and weak bases
Bases, like acids, are strong or weak.
Strong bases
Ionise completely in aqueous solution.
Sodium hydroxide (NaOH), potassium hydroxide (KOH).
Weak bases
Ionise only partly in aqueous solution.
Ammonia solution (NH4OH).
NaOH (aq) → Na+ (aq) + OH- (aq)
KOH (aq) → K+ (aq) + OH- (aq)
Alkali
Bases that dissolve well in water are called alkalis: sodium hydroxide, potassium hydroxide and ammonia solution.