Names & Formulas
of Ions
Steps for Naming Ions
1. Name polyatomic ions
2. Name remaining anions (change ending to –
ide)
3. Name remaining cations from groups 1, 2,
Ag+, Cd2+, Zn2+, Al3+. (use the name of the
element and add “ion”)
4. Name all remaining cations using the name
of the element followed by a roman numeral
equal to the positive charge of the cation.
1.
SO42-
2.
O2-
3.
Mg2+
4.
Pb2+
5.
NO2-
6.
Ag+
7.
Cu+
8.
NH4+
9.
P3-
10.
Cl3+
Examples
1.
SO42-
2.
O2-
3.
Mg2+
4.
Pb2+
5.
NO2-
6.
Ag+
7.
Cu+
8.
NH4+
9.
P3-
10.
Cl3+
Examples
Steps for Writing Formulas of Ions
•
1.
2.
3.
4.
Many people find that they wish to do these in the
order that they are presented. You can however use
the following order if you find it helpful
Polyatomic ions.
Remaining anions. (These will be anything left that
ends in –ide).
Remaining ions containing a Roman Numeral.
Remaining ions without a Roman Numeral. (get
the roman numeral from the table).
1. Cobalt (I) ion
2. Selenide ion
3. Phosphite ion
4. Nitrogen (V) ion
5. Arsenide ion
6. Hydroxide ion
7. Cadmium ion
8. Lithium ion
9. Calcium ion
10. Mercury (I) ion
Examples
1. Cobalt (I) ion
2. Selenide ion
3. Phosphite ion
4. Nitrogen (V) ion
5. Arsenide ion
6. Hydroxide ion
7. Cadmium ion
8. Lithium ion
9. Calcium ion
10. Mercury (I) ion
Examples
Homework
• Worksheet: Ion Formulas and Names.
• Lab Summary “Tap Water Test” (You do
not need to copy entire “Objective
Section” as your purpose).