Chemistry Nomenclature

The names of ionic compounds are written by listing the name of the positive ion followed by the name of the negative ion.

ie NaCl = sodium chloride
Fe2O3=iron (III) oxide

single atom positive ions carry the name of the element from which they are formed

Na+ = sodium
Ca2+ = calcium
H+ = hydrogen

The charge on the ion is indicated by a Roman numeral in parentheses immediately after the name of the element.

ie Fe(2+) = Iron (II)
Fe(3+) = Iron (III)

Common names ending with the suffix -onium

H3O+ = hydronium
NH4+ =ammonium

Negative ions that consist of a single atom are named by adding the suffix -ide to the stem of the name of the element.

F- = fluoride
O2- = oxide
Cl - = chloride
H- = hydride

1) The name of the ion usually ends in -ite or -ate.
2) The -ite ending indicates a low oxidation state. Thus the (NO2)- ion is the nitrite ion.
3) The -ate ending indicates a high oxidation state. Thus the (NO3)- ion is the nitrate ion.
4) When more than two polyatomic ions exist with the same central atom, the prefeix per- (as in hyper) and the prefix hypo- are used to indicate the very largest and very smallest number of oxygens.
Ex: ClO- = hypochlorite
(ClO2)- = chlorite
(ClO3)- = chlorate
(ClO4)- = perchlorate

acetate

carbonate

borate

nitrate

nitrite

sulfate

sulfite

perchlorate

chlorate

chlorite

hypochlorite

phosphate

permanganate

chromate