Naming Inorganic Compounds Chemistry-111

First you should review the nomenclature tutorial for Concepts of Chemistry and then you should return to this page. The main difference found in this tutorial versus the beginning tutorial is that...

You will be asked to learn more cations and anions and the nomenclature of acids in this tutorial.

Tables of Common Cations and Anions


+1 charge

+2 charge

+3 charge

+4 charge

+5 charge

H+      hydrogen

Ca2+         calcium

Al3+    aluminum

Pt4+          platinum(IV)

Sb5+    antimony(V)

Li+          lithium

Mn2+          manganese(II)

Fe3+            iron(III)

Sn4+                  tin(IV)

As5+            arsenic(V)

K+    potassium

Ba2+               barium

Sb3+    antimony(III)

Mn4+     manganese(IV)


Na+        sodium

Cu2+          copper(II)

Bi3+          bismuth

Pd4+       palladium(IV)


Ag+           silver

Fe2+                iron(II)

Cr3+       chromium(III)

Pb4+               lead(IV)


Cu+               copper(I)

Mg2+      magnesium

Co3+           cobalt(III)



NH4     ammonium

Zn2+             zinc

As3+        arsenic(III)



Rb+     rubidium

Cd2+        cadmium




Cs+              cesium

Sn2+               tin(II)




Au+            gold(I)

Hg2+      mercury(II)





Ni2+              nickel





Pb2+                lead(II)





Be2+         beryllium





Co2+           cobalt(II)





Cr2+        chromium(II)





Pt2+             platinum





Sr2+       strontium





Hg22+      mercury(I)





-1 charge

-2 charge

-3 charge

-4 charge

F- fluoride

O2- oxide

PO43- phosphate

C44- carbide

Cl- chloride

S2- sulfide

PO33- phosphite


Br- bromide

CO32- carbonate

BO33- borate


I- iodide

SO32- sulfite

P3- phosphide


OH- hydroxide

SO42- sulfate

N3- nitride


CN- cyanide

HPO42- hydrogen phosphate



HCO3- bicarbonate,   hydrogen carbonate

CrO42- chromate



NO2- nitrite

Cr2O72- dichromate



NO3- nitrate

C2O42- oxalate



CH3CO2- acetate




H2PO4- dihydrogen phosphate




HSO4- hydrogen sulfate




ClO- hypochlorite*




ClO2- chlorite*




ClO3- chlorate*




ClO4- perchlorate*




MnO4- permanganate




 * Bromine and iodine also form most of these groups...hypobromite, bromite, bromate, perbromate, hypoiodite, iodate and periodate.

Note that the ___-ate anions contain one more oxygen atom than the ___-ite anions and two more oxygen atoms than the hypo-___-ite anions. The per-___-ate anions contain one more oxygen atom than the ___-ate anions.

Notice that the charge or valence can usually be predicted for the elements in columns IA, IIA, IIIA, IVA, VA, VIA and VIIA of the periodic table because those elements will gain or lose the smallest number of electrons to obtain inert gas shells.

Examples of Ionic Inorganic Compounds Try to figure out the name or formula and then click on the button to see the correct answer. Click "back" on your browser to return to this page.


ammonium nitrate


sodium hydrogen carbonate


mercury(II) sulfide


potassium permanganate

Non-ionic inorganic compounds (molecular inorganic compounds) are combinations of nonmetallic elements. Most of these compounds are combinations of elements from Groups IVA to VIIA with one another or with hydrogen. The following binary compounds are named in the following systematic manner.

When a hydrogen atom forms compounds with the nonmetals, the hydrogen atom is named first and the nonmetal is named as if it were a negative ion.

HF (g)

hydrogen fluoride...The (g) must be shown since the hydrogen halides in aqueous solutions are named as acids.

H2S (g)

hydrogen sulfide...same comment as above.

H2O is not known by dihydrogen oxide

NH3 is not known by trihydrogen nitride


methane...this is considered the proper name


hydrazine...this is considered the proper name


phosphine...this is considered the proper name

When other elements combine to form binary compounds, the formula is usually written by putting the elements in order of increasing group number. The number of atoms is given by a prefix, such as "di", "tri", "tetra", "penta", "hexa". Always use the entire prefix except for monooxide...which is monoxide and never use the mono prefix for the first element. Always use a prefix for the second element.


carbon monoxide


nitrogen monoxide...nitric oxide


dinitrogen monoxide...nitrous oxide..."laughing gas"


phosphorus trichloride


carbon tetrachloride


sulfur trioxide


diphosphorus pentaoxide

Many compounds that contain hydrogen atoms are known as acids and have their own names. These compounds give up a hydrogen cation (proton) when dissolved in water. The names of these acids are derived from the names of the anions that are produced in these reactions.

If the anion name ends in -ide, the acid name consists of the following parts...

...the prefix hydro-

...the stem of the anion name

...the suffix -ic

...the word acid 

HF (aq)

hydrofluoric acid...The (aq) must be shown since the hydrogen halides are also gases.

HCN (aq)

hydrocyanic acid...same comment as above.

H2S (aq)

hydrosulfuric acid (The ur is added to aid pronounciation.)

H2O (aq)

hydrooxic acid...J This is a joke.  

If the anion name ends in -ate, the acid name consists of the following parts...

...the name of the anion less the -ate ending

...the suffix -ic

...the word acid


nitric acid


perchloric acid


sulfuric acid


phosphoric acid


acetic acid


carbonic acid


chloric acid 

If the anion name ends in -ite, the acid name consists of the following parts...

...the name of the anion less the -ite ending

...the suffix -ous

...the word acid


phosphorous acid


nitrous acid


hypochlorous acid


chlorous acid  

Several series of oxyacids exist as represented by the compounds; perchloric acid, chloric acid, chlorous acid and hypochlorous acid. This series is repeated for bromine.

These compounds are named from their respective polyatomic anions, which are called oxyanions.

Iodine only forms periodic acid, iodic acid and hypoiodous acid.

Fluorine only forms hypofluorous acid.

Phosphorus forms phosphoric acid and phosphorous acid.

Sulfur forms sulfuric acid and sulfurous acid.

Nitrogen forms nitric acid and nitrous acid.

Examples of Molecular Inorganic Compounds Try to figure out the name or formula and then click on the button to see the correct answer.


nitrogen dioxide

HBr (g)

sulfur trioxide

HCl (g)

carbon dioxide



HCl (aq)

nitrogen trifluoride


nitric acid


perbromic acid


phosphorous acid

Deciding Which Nomenclature Rules to Follow

1. Determine whether the compound is an ionic compound or a molecular compound.

If a metal is present, the compound is an ionic compound for the purposes of this course. If no metal is present, the compound is a molecular compound.

If the ammonium ion, NH4+ is present, the compound is ionic.

2. If the compound is ionic, use the names and charges given in the tables.

3. If the compound is a molecular compound, decide if it is an acid or a non-acid.

In order to be an acid, it must have hydrogen atoms that are written first in the molecular formula and in most cases it will be in an aqueous solution.

4. If it is an acid, use the rules for naming acids.

5. If it is not an acid, use the rules for naming binary molecular compounds.

Copyright January 2001 by Richard C. Banks...all rights reserved.