Section 2.8

Naming Inorganic Compounds

Chemical NomenclatureNaming system of substancesLatin:

◦Nomen~ name Calare~ to callTwo main categories:

◦Organic and Inorganic

Inorganic Compound Rules

Ionic

MolecularAcids

Ionic Compounds

Cations

Anions

Compounds

Ionic Compounds1. Cations

◦a) Same name as the metal they formed from: Na+ sodium ion

◦ b) Metals forming different cations: use Roman numerals in parentheses:

Fe2+ iron (II) ion Fe 3+ iron (III) ion

~ Older method: -ous or –ic ending

Fe2+ ferrous ion Fe3+ ferric ion

Ionic Compounds c) Cations formed from nonmetal

atoms have names that end in –ium

NH4+ ammonium ion

H3O+ hydronium ion

Ionic Compounds 2. Anions

◦a) Monoatomic anions are formed by replacing ending of name of element with –ide

O2- oxideN3- nitride

◦b) Polyatomic anions contain oxygen (oxyanions) end in –ate or –ite

NO3- nitrate

NO2- nitrite

Ionic Compounds◦b) Polyatomic anions contain oxygen

(oxyanions) end in –ate or –ite ◦ -ite has one fewer O atoms than an –ate

NO3- nitrate

NO2- nitrite

◦Prefixes per- and –hypo are used when there are more than four members

ClO4- perchlorate

ClO3- chlorate

ClO2- chlorite

ClO- hypochlorite

Ionic Compoundsc) Anions derived from adding

H+ to an oxyanion: begin with either hydrogen or dihydrogen

CO32- carbonate

HCO3- hydrogen carbonate

PO43- phosphate

H2PO43- dihydrogen phosphate

Ionic Compounds3. Compounds

◦Names consist of the cation name followed by the anion name

CaCl2 calcium chloride

AlPO3 aluminum phosphite

CuSO4 copper (II) sulfate

Acids

-ides

-ates

/-ites

Acids1. With anions ending in –ide:

change –ide to –ic, add the prefix hydro-, and follow with the word acid

Anion Corresponding Acid

Cl- (chloride) HCl (hydrochloric acid)

S2- (sulfide) H2S (hydrosulfuric acid

Acids2. With anions ending in –ate or –

ite:◦Change –ate to –ic◦Change –ite to –ous◦Add the word acid

Anion Corresponding Acid

ClO4- (perchlorate) HClO4 (perchloric acid)

ClO3- (chlorate) HClO3 (chloric acid)

ClO2- (chlorite) HClO2 (chlorous acid)

ClO- (hypochlorite) HClO (hypochorous acid)

Molecular Compounds (Binary)1. Name the element farther to

the left in the periodic table first.2. If both in same group, the one

with the higher atomic number is named first.

3. Name the second with an –ide ending

4. Greek prefixes are used to indicate number of atoms of each element