Nomenclature - Ionic Compounds
Dr. MJ Patterson
To use this set of rules, the compound must be ionic. In other words, it must be a metal + a nonmetal. Or, it must contain one or more of the polyatomic ions.
Naming Polyatomic Ions
The polyatomic ions have names that you need to memorize. See the previous Additional Study activity from the course web page.
Naming Main Group Metal Cations
A main group cation is named as the element followed by the word ion.
Example 1:
Name the following cations.
a. Na+
b. Al3+
c. Ba2+
Solution 1:
a. Na+ sodium ion
b. Al3+
aluminum ion
c. Ba2+ barium ion
Naming Transition Metal Cations
Since the transition metals can have various charges, you must specify the
charge of the ion in the name with a Roman numeral in parentheses.
|
Roman Numeral |
I |
II |
III |
IV |
V |
VI |
VII |
|
Arabic Numeral |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
Example 2:
Name the following transition metal cations.
a. Mn2+
b. Mn7+
c. Fe2+
d. Fe3+
Solution 2:
a. Mn2+ manganese(II)
ion
b. Mn7+ manganese(VII)
ion
c. Fe2+ iron(II)
ion
d. Fe3+ iron(III)
ion
Naming Main Group Anions
The main group anions are named by placing the -ide ending on the element name and adding the word ion.
Example 3:
Name the following anions.
a. Cl-
b. O2-
c. N3-
d. F-
Solution 3:
a. Cl- chloride ion
b. O2-
oxide ion
c. N3-
nitride ion
d. F- fluoride
ion
Naming Ionic Compounds
To name an entire ionic compound, name the cation followed by the anion. Omit the word "ion."
Example 4:
Name the following ionic compounds.
a. NaCl
b. BaF2
c. FeCl2 (iron has a +2 charge)
d. CaO
e. NH4NO3
Solution 4:
a. NaCl sodium chloride
b. BaF2
barium fluoride
c. FeCl2 (iron has a +2
charge) iron(II) chloride
d. CaO calcium oxide
e. NH4NO3
ammonium nitrate