Naming Acids Dr. Jerry E. Sipe Ivy Tech Community College

What You Need To Know Acid nomenclature is different from other compound nomenclature Acids are named for their anions because they have a common cation: H + Other compounds are named for their cations and their anions

Classification of Acids Classified by the number of hydrogen ions produced – Monoprotic: HCl  H + + Cl - – Diprotic: H 2 SO 4  2 H + + SO 4 -2 – Triprotic: H 3 PO 4  3 H + + PO 4 -3 –Recognizing this classification is vital when stoichiometry/balancing equations are required

Classified by type of anion –Binary: monatomic anion: HCl –Tertiary: polyatomic anion: H 2 SO 4 – Recognizing this classification is vital in naming acids and writing formulas from their names Classification of Acids

Formula writing begins with analyzing the key parts of the name Binary acids are recognized by the following: HYDROELEMENTIC Writing Acid Formulas: Binary Acids H+H+ E -X CROSS MULTIPLY CHARGES HXEHXE

Hydrochloric Acid Indicates a binary acid containing chlorine H+H+ Cl - H 1 Cl 1

POLYATOMICSTEMOUS ACID Writing Acid Formulas:Tertiary Acids – Names ending in “ous” H+H+ ZO -X CROSS MULTIPLY CHARGES H X ZO

Nitrous Acid Indicates a polyatomic anion with lowest amount of oxygen in nitrogen series (nitrite) H+H+ NO 2 - H 1 1 NO 2

POLYATOMICSTEMIC ACID Writing Acid Formulas:Tertiary Acids – Names ending in “IC” H+H+ ZO 2 -X CROSS MULTIPLY CHARGES H X ZO 2

Sulfuric Acid Indicates a polyatomic anion with highest amount of oxygen in sulfur series H+H+ SO 4 -2 H 21 SO 4

Perchloric acid Indicates a polyatomic anion with highest amount of oxygen in chlorine series H+H+ ClO 4 - H 1 1 ClO 4

Hydrophosphoric Acid Indicates a binary acid containing phosphorous H+H+ P -3 H 3 P 1

Hydroiodic Acid Indicates a binary acid containing iodine H+H+ I-I- H 1 I 1

Hypochlorous Acid Indicates a polyatomic ion with the lowest level of oxygen in the chlorine series H+H+ ClO - H 1 ClO 1

Acid names derived from the anion Binary acids: HYDROELEMENTIC ACID Example: HI  IODIDE ion is anion Therefore the name of the acid is –HYDROIODIC ACID Naming of Acids: Formula to Name

Tertiary acids “ite” ending: ITE  OUS –ION NAME STEMOUS ACID –Example: HPO 3 ; PO 3 -3 is the phosphite ion; therefore, the name of the acid is PHOSPHOROUS ACID –Note: the “OR” in the name is added to complete the elemental name Naming of Acids: Formula to Name

Tertiary acids “ic” ending: ATE  IC –ION NAME STEMIC ACID –Example: HPO 4 ; PO 4 - is phosphate ion; therefore, the name of the acid is PHOSPHORIC ACID –Note: the “OR” in the name is added to complete the elemental name Naming of Acids: Formula to Name

H2SH2SH2SH2S Only one element (sulfur) other than hydrogen – a binary acid; therefore… HydrosulfuricAcid

H 2 SO 3 SulfiteIon SulfurousAcid

HNO 3 NitrateIon NitricAcid

HF Only one element (fluorine) other than hydrogen – a binary acid; therefore… HydrofluoricAcid

HClO 3 ChlorateIon ChloricAcid

HIO HypoioditeIon HypoiodousAcid