Naming Inorganic Compounds

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

Cations

+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)

Anions

-1 charge	-2 charge	-3 charge	-4 charge
F^- fluoride	O^2- oxide	PO₄^3- phosphate	C₄^4- carbide
Cl^- chloride	S^2- sulfide	PO₃^3- phosphite
Br^- bromide	CO₃^2- carbonate	BO₃^3- borate
I^- iodide	SO₃^2- sulfite	P^3- phosphide
OH^- hydroxide	SO₄^2- sulfate	N^3- nitride
CN^- cyanide	HPO₄^2- hydrogen phosphate
HCO₃^- bicarbonate, hydrogen carbonate	CrO₄^2- chromate
NO₂^- nitrite	Cr₂O₇^2- dichromate
NO₃^- nitrate	C₂O₄^2- 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.

· Fe₂O₃

· ammonium nitrate

· MgCl₂

· sodium hydrogen carbonate

· CaCO₃

· mercury(II) sulfide

· NaClO

· 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	water...it is not known by dihydrogen oxide
NH₃	ammonia...it is not known by trihydrogen nitride
CH₄	methane...this is considered the proper name
N₂H₄	hydrazine...this is considered the proper name
PH₃	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.

CO	carbon monoxide
NO	nitrogen monoxide...nitric oxide
N₂O	dinitrogen monoxide...nitrous oxide..."laughing gas"
PCl₃	phosphorus trichloride
CCl₄	carbon tetrachloride
SO₃	sulfur trioxide
P₂O₅	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

HNO₃	nitric acid
HClO₄	perchloric acid
H₂SO₄	sulfuric acid
H₃PO₄	phosphoric acid
HC₂H₃O₂	acetic acid
H₂CO₃	carbonic acid
HClO₃	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

H₃PO₃	phosphorous acid
HNO₂	nitrous acid
HClO	hypochlorous acid
HClO₂	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.

· SO₂

· nitrogen dioxide

· HBr(g)

· sulfur trioxide

· HCl(g)

· carbon dioxide

· NH₃

· methane

· HCl(aq)

· nitrogen trifluoride

· PBr₅

· nitric acid

· H₂SO₄

· perbromic acid

· HC₂H₃O₂

· 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.