Rules for Naming Binary Ionic Compounds Containing a Metal Ion With a Variable Charge - Chemistry HW 10/3/10

Rule 1. The cation is written first in the name; the anion is written second in the name.

Rule 2. The name of the cation is the same as the element from which it is derived.  Cations are usually metals. The charge on the cation is indicated using a Roman numeral, in parentheses, immediately following the name of the cation (e.g., Fe³⁺ = "iron(III)"). This is also called the Stock system.

The rule to follow in giving such names is this:

For the lower charge, use the suffix  -ous;

For the higher charge, use the suffix –ic;

Thus, iron(II) takes the common name ferrous while iron(III), ferric.

Rule 3. The anion is named by adding the suffix -ide to the root of the element name (e.g., I^- = "iodide").