For example, hydrochloric acid (HCl) is a monoprotic acid because it can release one H+ ion in water: HCl (aq) ⇌ H+ (aq) + Cl- (aq)

_Diprotic acid: _An acid that can donate two hydrogen ions (H+) in water.

For example, sulfuric acid (H2SO4) is a diprotic acid because it can release two H+ ions in water in two successive steps:

H2SO4 (aq) ⇌ H+ (aq) + HSO4 -(aq)

HSO4- (aq) ⇌ H+ + SO4(2-) (aq)

Triprotic acid: An acid that can donate three hydrogen ions (H+) in water.

For example, phosphoric acid (H3PO4) is a triprotic acid because it can release three H+ ions in water in three successive steps:

H3PO4 (aq) ⇌ H+ (aq) + H2PO4- (aq)

H2PO4- (aq) ⇌ H+ (aq) + HPO4(2-) (aq)

HPO4(2-) (aq) ⇌ H+ (aq) + PO4(3-) (aq)