Chem 111/121 9/10/02
Nomenclature Worksheet 3: Naming of Transition metal salts
Like all metals, when transition metals combine with a nonmetal they form ionic compounds. They
differ from the Group A elements in that they can form cations with different charges. For example
iron can form both Fe2+ and Fe3+ ions. Because of this the charge (or oxidation state) of the metal in
the compound is usually included in the name. This is done by writing the oxidation state as a roman
numeral in parentheses directly following the name of the element. Sometimes older nomenclature is
used where the lower oxidation state is given an “ous” ending, the higher is given an “ic” ending. For
Chem 111 you should use the roman numeral (IUPAC) method.
IUPAC Name
Older name
Fe2+
iron(II) ion
Ferrous ion
Fe3+
iron(III) ion
Ferric ion
The charge for certain elements is so common that it is often not stated. Here are some exceptions:
Accepted Name
IUPAC Name
Ni2+
nickel ion
nickel(II) ion
Cu2+
copper ion
copper(II) ion
Ag+
silver ion
silver(I) ion
Zn2+
zinc ion
never written as zinc(II)
In addition to the transition metals, the Group 4A metals tin and lead can have +2 or +4 oxidation
states. These are specified in the same manner: lead(IV), tin(II) and tin(IV). Pb2+ is just called lead
ion.
Name of compound
Formula of compound
1. chromium(II) chloride
CrCl2
2. copper(I) oxide
Cu2O
3. cobalt(II) sulfide
CoS
4. silver bromide
AgBr
5. iron(II) nitride
Fe3N2
6. copper fluoride
CuF2
7. zinc iodide
ZnI2
8. lead(IV) oxide
PbO2
9. tin(II) chloride
SnCl2
10. manganese(III) oxide
Mn2O3
11. tin(II) fluoride or stannous fluoride
(in fluoride toothpaste)
SnF2
12. copper sulfide or copper(II) sulfide
CuS
13. zinc phosphide
Zn3P2
14. nickel bromide or nickel(II) bromide
NiBr2
15. chromium(II) oxide
CrO
16. silver iodide or silver(I) iodide
AgI
17. iron(III) chloride or ferric chloride
FeCl3
18. cobalt(III) oxide
Co2O3
19. lead sulfide or lead(II) sulfide
PbS
20. silver sulfide or silver(I) sulfide
Ag2S
