Chemical Nomenclature & Bonding

Chemical Nomenclature & Bonding GO BACK

Ionic

Recognize ionic compounds because they:

a. Are binary compounds that contain a metal and a non-metal.
b. Contain polyatomic ions.

Use the periodic table to predict charges on some atoms with certainty.

1. The metal (retains element name) or polyatomic cation is first. If the metal is Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Ra, or Al the charge is never indicated. The charge is known from the periodic table.

NaCl sodium chloride

NH₄Br ammonium bromide

2. Followed by the name of the nonmetal with an -ide ending added or the polyatomic anion.

KCl potassium chloride

Ca(NO₃)₂ calcium nitrate

3. If the metal has more than one possible charge, indicate the charge using roman numerals (and no space):

FeCl₂ iron(II) chloride

CuSO₄ copper(II) sufate

An incorrect, but still frequently seen, method uses the Latin root and an added -ous for the lower charge or -ic for the higher charge. (Fe(ClO₃)₂, ferrous chlorate; Fe(ClO₂)₃, ferric chlorite). Do not use this method.

Polyatomic Ions.

1. Cations.

Formula	Name
NH₄⁺	ammonium ion
Hg₂²⁺	mercury(I)

2. Anions.

a. Only a few polyatomic anions have an -ide ending.

Formula	Name
CN^-	cyanide
OH^-	hydroxide
O₂^2-	peroxide
O₂^-	superoxide
N₃^-	azide

b. Oxyanions. -ate more oxygen, -ite less oxygen

Formula	Name
NO₂^-	nitrite
NO₃^-	nitrate
SO₃^2-	sulfite
SO₄^2-	sulfate
PO₃^3-	phosphite
PO₄^3-	phosphate

c. Sometimes oxyanions have an extra hydrogen

Formula	Name
SO₄^2-	sulfate
HSO₄^-	hydrogen sulfate (or bisulfate)
SO₃^2-	sulfite
HSO₃^-	hydrogen sulfite (or bisulfite)
PO₄^3-	phosphate (tribasic)
HPO₄^2-	hydrogen phosphate (dibasic)
H₂PO₄^-	dihydrogen phosphate (monobasic)

d. Sometimes there are more than two ions, sometimes only one

Formula	Name
ClO^-	hypochlorite
ClO₂^-	chlorite
ClO₃^-	chlorate
ClO₄^-	perchlorate

CO₃^2-	carbonate
HCO₃^-	hydrogen carbonate ( or bicarbonate)
C₂H₃O₂^-	acetate

e. Metals can also form oxyanions

Formula	Name
MnO₄^-	permanganate
CrO₄^2-	chromate
Cr₂O₇^2-	dichromate

Examples

Compound	Name
FeS	iron(II) sulfide
Fe₂O₃	iron(III) oxide
Hg₂Br₂	mercury(I) bromide
Hg(N₃)₂	mercury(II) azide
CuI	copper(I) iodide
Cu(ClO₄)₂	copper(II) perchlorate
SnF₂	tin(II) fluoride
SnCl₄	tin(IV) chloride

Molecular

Recognize molecular compound because they are binary and contain only non-metals.

1. Start with element to the left side (most metallic) on the periodic table followed by the second element with an added -ide (as if it were an anion) as a suffix.

2. Always use Greek prefixes to indicate the number of each type of atom in the compound:

mono di tri tetra penta hexa hepta octa nona deca

1 2 3 4 5 6 7 8 9 10

CO carbon monoxide

CO₂ carbon dioxide

N₂O₅ dinitrogen pentoxide

Do not use mono for the first element. In some cases, drop adjacent vowels caused by a prefix.

Formula	Name
N₂O	dinitrogen monoxide	nitrogen (I) oxide	nitrous oxide
NO	nitrogen monoxide	nitrogen (II) oxide	nitric oxide
N₂O₃	dinitrogen trioxide	nitrogen (III) oxide
NO₂	nitrogen dioxide	nitrogen (IV) oxide
N₂O₅	dinitrogen pentoxide	nitrogen (V) oxide
CI₄	carbon tetraiodide
S₂Cl₂	disulfur dichloride

Acids

1. Hydro acids: hydro + halogen name + ic

Formula	Name
HCl	hydrochloric acid
HF	hydrofluoric acid

2. Oxoacids: polyatomic ion + acid. Recognize as polyatomic ions with a hydrogen at the beginning of the formula. Name with -ous (replacing -ite and -ic replacing -ate suffix)

Formula	Name	Source
HNO₃	nitric acid	nitric from nitrate
HNO₂	nitrous acid	nitrous from nitrite
H₂SO₄	sulfuric acid	sulfuric from sulfate
H₂SO₃	sulfurous acid	sulfurous from sulfite

Additional Information PowerPoint

Nomenclature Quiz

IUPAC Nomenclature

Organic Nomenclature (IUPAC) Search IUPAC Organic Nomenclature

Last modified

Contact us for more info