Naming AcidsNaming Acids

Dr. Jerry E. SipeDr. Jerry E. Sipe

Ivy Tech Community CollegeIvy Tech Community College

What You Need To KnowWhat 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 AcidsClassification of Acids

• Classified by the number of hydrogen ions produced– Monoprotic: HCl H+ + Cl-

– Diprotic: H2SO4 2 H+ + SO4-2

– Triprotic: H3PO4 3 H+ + PO4-3

– Recognizing this classification is vital when stoichiometry/balancing equations are required

• Classified by type of anion

– Binary: monatomic anion: HCl

– Tertiary: polyatomic anion: H2SO4

– Recognizing this classification is vital in naming acids and writing formulas from their names

Classification of AcidsClassification of Acids

• Formula writing begins with analyzing the key parts of the name

• Binary acids are recognized by the following:

• HYDROELEMENTIC

Writing Acid Formulas:Writing Acid Formulas:Binary AcidsBinary Acids

H+ E-XCROSS MULTIPLY CHARGES

HXE

Hydrochloric AcidHydrochloric Acid

Indicates a binary acid containing chlorine

H+ Cl-

H1Cl 1

• POLYATOMICSTEMOUS ACID

Writing Acid Formulas:Tertiary Writing Acid Formulas:Tertiary Acids – Names ending in “ous” Acids – Names ending in “ous”

H+ ZO-XCROSS MULTIPLY CHARGES

HXZO

Nitrous AcidNitrous Acid

Indicates a polyatomic anion with lowest amount of oxygen in nitrogen series (nitrite)

H+ NO2-

H1 1NO2

• POLYATOMICSTEMIC ACID

Writing Acid Formulas:Tertiary Writing Acid Formulas:Tertiary Acids – Names ending in “IC” Acids – Names ending in “IC”

H+ ZO2-X

CROSS MULTIPLY CHARGES

HXZO2

Sulfuric AcidSulfuric Acid

Indicates a polyatomic anion with highest amount of oxygen in sulfur series

H+ SO4-2

H2 1SO4

Perchloric acidPerchloric acid

Indicates a polyatomic anion with highest amount of oxygen in chlorine series

H+ ClO4-

H1 1ClO4

Hydrophosphoric AcidHydrophosphoric Acid

Indicates a binary acid containing phosphorous

H+ P-3

H3P1

Hydroiodic AcidHydroiodic Acid

Indicates a binary acid containing iodine

H+ I-

H1I1

Hypochlorous AcidHypochlorous Acid

Indicates a polyatomic ion with the lowest level of oxygen in the chlorine series

H+ ClO-

H1ClO1

• 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: Naming of Acids: Formula to NameFormula to Name

• Tertiary acids “ite” ending: ITE OUS– ION NAME STEMOUS ACID

– Example: HPO3; PO3-3

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: Naming of Acids: Formula to NameFormula to Name

• Tertiary acids “ic” ending: ATE IC– ION NAME STEMIC ACID

– Example: HPO4; PO4- 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: Naming of Acids: Formula to NameFormula to Name

HH22SS

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

Hydrosulfuric Acid

HH22SOSO33

Sulf ite Ion

Sulfurous Acid

HNOHNO33

Nitrate Ion

Nitric Acid

HFHF

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

Hydrofluoric Acid

HClOHClO33

Chlorate Ion

Chloric Acid

HIOHIO

Hypoiodite Ion

Hypoiodous Acid