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SNC2D - Chemistry
Ionic Compounds with Multivalent Metals
Most transition metals and some metals in group 14 (or IVA) are multivalent (they have more than one
possible valence). They can form different numbers of bonds depending on the conditions.
There are 2 systems of rules for naming compounds with metals of variable valence: IUPAC
(international) and “Classical” (“ous-ic”). We will learn the IUPAC system.
International System
Writing
Formulas:
1. Use the regular methods for writing formulas of ionic compounds (ionic
charge or criss-cross). The metal is written first, and then the non-metal.
2. For the metal, use the charge given in brackets.
Examples:
copper (II) nitride
tin (IV) oxide
Cu+2 N-3
Sn+4
Cu3N2
Sn2O4
O-2
Reduces to SnO2
Writing Names:
1. From the formula, determine the total amount of negative charge.
2. Multiply the anion subscript by the charge on the anion to determine the
negative charge.
3. The amount of positive charge must equal the amount of negative charge.
Determine the charge on the cation by dividing the total positive charge by
the number of cations (from the subscript in the formula).
4. Write the names of the elements in the same order as the formula (metal
first, followed by the non-metal with “ide” suffix)
5. Use Roman numerals in brackets following the metal to indicate the charge
of the cation.
Examples:
a)
1
FeI2
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SNC2D - Chemistry
b) Ni2O3
c) Cu3N2
Therefore the name is copper (II) nitride
Practice I. Write the correct formulas for the following:
1. cobalt (II) sulfide
11. tin (IV) iodide
2. chromium (III) bromide
12. copper (I) oxide
3. lead (II) oxide
13. lead (III) phosphide
4. gold (I) oxide
14. manganese (IV) oxide
5. tin (II) sulfide
15. nickel (III) sulfide
6. iron (III) nitride
16. lead (IV) bromide
7. bismuth (V) carbide
17. scandium (II) iodide
8. gold (I) sulfide
9. tin (IV) carbide
10. copper (II) nitride
Practice II. Write names for the following
3. PbO2
1. SnF4
4. HgCl
2. FeS
5. Ni2O3
2
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6. Cu3N
7. AuF3
8. CuI
9. PbCl4
10. CuCl2
11. CoF3
12. FeO
13. MnCl7
14. Cr3N2
15. Sn3P2
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SNC2D - Chemistry