1. Multi-Valent Metals Compound Naming
Science 10
Section 5.3 p

2. Multi-valent Metals - Naming
To name multi-valent transition metals we use the Stock system.
In the Stock system, the charge of the metal is indicated by a Roman numeral written after the name of the metal.
Fe2O3 - iron(III) oxide
FeO - iron(II) oxide
PbO2 - lead(IV) oxide
The Stock system should not be used for metals that have only one possible charge.

3. Roman Numerals 1 = I 2 = II 3 = III 4 = IV 5 = V 6 = VI 7 = VII
8 = VIII
9 = IX
10 = X

4. “Reverse Cross-over” Method
When you name a compound containing a multi-valent metal you will have to determine the charge on the multi-valent metal.
If you reverse the cross-over method you used for binary ionic compounds, you will be able to determine the charge on the ions.
Ex: FeCl3 FeO
Fe3+Cl- Fe+O-
Iron(III)chloride Fe2+O2-
Iron (II) oxide
Try this: Cu2S