Naming Ionic Compounds
A binary compound is a compound formed of exactly two different elements. Binary ionic compounds contain two elements in ionic form—a cation and an anion. These compounds are named after the ions that make them up. Cations have the same name as their element name. For example,a cation formed from a sodium atom is called a sodium ion, and a cation formed from a magnesium atom is called a magnesium ion. An anion is given a slightly different name than its element name. To name an anion, start with a prefix designating the element name and add the suffix “-ide.” Thus, the anion of a bromine atom is called a bromide ion. The prefix “brom-” indicates that bromine is the element, and the suffix “-ide” indicates that you are referring to the anion of that element.Two more examples of this naming system are the oxide ion, which is the anion of oxygen and chloride, the anion of chlorine.
When naming a binary ionic compound, the cation name comes first; the name of the anion follows. So, KBr is named potassium bromide, CaCl2 is named calcium chloride, and Li3N is named lithium nitride.
Table 3 summarizes the cations and anions you need to be familiar with. Note that the names of several polyatomic ions are also included.
When naming a binary ionic compound, the cation name comes first; the name of the anion follows. So, KBr is named potassium bromide, CaCl2 is named calcium chloride, and Li3N is named lithium nitride.
Table 3 summarizes the cations and anions you need to be familiar with. Note that the names of several polyatomic ions are also included.
Compounds containing polyatomic ions are named the same way as binary ionic compounds. For example, NaNO3 is named sodium nitrate because it is composed of a sodium ion and a nitrate ion.
