NAMING COMPOUNDS

6.1 - Binary Compounds

6.1.3 - Binary compounds containing metals with variable ionic charges

In section 6.1.2 we learned that some metals on the periodic table have fixed ionic charges. All the other metals that are not on the list of metals with fixed ionic charges are metals with variable ionic charges. Review the 13 metals with fixed ionic charges. Click on the button below to review the fixed charges associated with these 13 metals.

Many metals on the periodic table have variable charges. For example:

• the element iron, Fe, can occur as +2 ions in some compounds and can occur as +3 ions in other compounds.

With this type of metals which can have variable charges, you have to consider the charge associated with the metal cations.

Here are some examples of binary compounds containing metals with variable ionic charges:

Latin Names:

Some metal ions with variable charges have Latin names. Because Latin names are still widely used in today's literature, we need to learn some Latin names of a few common metal ions. In this course we will restrict to learn the Latin names of 5 common metal ions so that if you are given a compound that has a Latin metal name, you will be able to write the chemical formula for the compound.

Rules for naming binary compounds containing metals with variable ionic charges:

1. Determine the charge of the metal in the compound.
2. Name the metal followed by a Roman numeral in parentheses immediately following the name of the metal. The Roman numeral represents the charge of the metal.
3. Name the nonmetal with the ending -ide.
4. No Greek prefixes necessary here because the charge on the metal is labelled, therefore, in forming a compound, there is only one possible combination with the nonmetal.

Let's apply the above rules and name the above examples. Click on each formula to check the name of each compound.

Section 7.3
Binary Compounds Containing a Metal and a Nonmetals ..p168

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