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Naming Chemical Compounds

Introduction

There are different classes of chemical compounds and different methods for naming them. The first place to start in naming compounds is with the periodic table. Names of compounds are usually derived from the names of the elements in the compound.

Naming inorganic compounds

metal containing

Compounds containing a metal will be based on the name of the elemental metal plus the name of the anion. The name of simple nonmetal anions convert the ending of the element name with -ide. Polyatomic anions usually end with -ite or -ate. (Note that hydroxide, OH^-, is an exception.)

common anions containing nonmetals
symbol name symbol name symbol name symbol name
F^- fluoride
Cl^- chloride ClO₂^- chlorite ClO₃^2- chlorate ClO₄^- perchlorate
Br^- bromide BrO₃^2- bromate

I^- iodide IO₃^2- iodate

O^2- oxide OH^- hydroxide O₂^2- peroxide

S^2- sulfide SO₃^2- sulfite SO₄^2- sulfate

Se^2- selenide
N^3- nitride NO₂^- nitrite NO₃^- nitrate
P^3- phosphide PO₄^3- phosphate
As^3- arsenide AsO₃^2- arsenate
C^4- carbide CO₃^2- carbonate
Si^4- silicide SiO₄^4- silicate

a few more
HCO₃^- hydrogen carbonate (bicarbonate)

HSO₃^- hydrogen sulfite (bisulfite)

HSO₄^- hydrogen sulfate (bisulfate)

HPO₄^2- hydrogen phosphate

H₂PO₄^- dihydrogen phosphate

common organic anions
CH₃COO^- acetate

HCOO^- formate

C₂O₄^2- oxalate

common anions containing metals
MnO₄^- permanganate

CrO₄^2- chromate

Cr₂O₇^2- dichromate

**common anions containing nonmetals**
symbol	name	symbol	name	symbol	name	symbol	name
F^-	fluoride
Cl^-	chloride	ClO₂^-	chlorite	ClO₃^2-	chlorate	ClO₄^-	perchlorate
Br^-	bromide			BrO₃^2-	bromate
I^-	iodide			IO₃^2-	iodate
O^2-	oxide	OH^-	hydroxide			O₂^2-	peroxide
S^2-	sulfide	SO₃^2-	sulfite	SO₄^2-	sulfate
Se^2-	selenide
N^3-	nitride	NO₂^-	nitrite	NO₃^-	nitrate
P^3-	phosphide			PO₄^3-	phosphate
As^3-	arsenide			AsO₃^2-	arsenate
C^4-	carbide			CO₃^2-	carbonate
Si^4-	silicide			SiO₄^4-	silicate

**a few more**
HCO₃^-	hydrogen carbonate (bicarbonate)
HSO₃^-	hydrogen sulfite (bisulfite)
HSO₄^-	hydrogen sulfate (bisulfate)
HPO₄^2-	hydrogen phosphate
H₂PO₄^-	dihydrogen phosphate

**common organic anions**
CH₃COO^-	acetate
HCOO^-	formate
C₂O₄^2-	oxalate

**common anions containing metals**
MnO₄^-	permanganate
CrO₄^2-	chromate
Cr₂O₇^2-	dichromate

Metals with multiple oxidation states use a Roman numeral in parentheses to specify the oxidation state. Example:

formula write as read as

FeCl₂ iron(II) chloride iron two chloride

FeCl₃ iron(III) chloride iron three chloride

formula	write as	read as
FeCl₂	iron(II) chloride	iron two chloride
FeCl₃	iron(III) chloride	iron three chloride

nonmetals

The name of nonmetallic compounds use the name of the first element in the formula followed by the name for the other elements in the compound, modified as above. A prefix indicates the number of each atom in the compound. Examples:

formula read as

CO carbon monoxide

CO₂ carbon dioxide

SO₂ sulfur dioxide

SO₃ sulfur trioxide

N₂O₅ dinitrogen pentoxide

formula	read as
CO	carbon monoxide
CO₂	carbon dioxide
SO₂	sulfur dioxide
SO₃	sulfur trioxide
N₂O₅	dinitrogen pentoxide

Naming Complexes

Complex ions are named with the ligand names added as prefixes to the name of the central metal ion. Anionic ligands are modified with the suffix -o, for example: chloro, Cl^-, cyano, CN^-, and hydroxo, OH^-. Most neutral ligands retain their usual name, a few exceptions are:

formula ligand name

C=O carbonyl

H₂O aqua

NH₃ ammine

formula	ligand name
C=O	carbonyl
H₂O	aqua
NH₃	ammine

formula read as

Cu(H₂O)₄^2- tetraaquacopper(II)

CoCl₆^3- hexachlorocobalt(III)

formula	read as
Cu(H₂O)₄^2-	tetraaquacopper(II)
CoCl₆^3-	hexachlorocobalt(III)

The names of complex ions are used in names of salts as described for other ions above. Cationic complexes are used as is and anionic complexes have -ate added as a suffix. For example:

coming soon...

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