Rules for Naming Binary Ionic Compounds
Rules for Naming Binary Ionic Compounds
Order of Naming: The metal is named first, followed by the non-metal.
Metals in Specific Groups:
If the metal is from Group 1, Group 2, or one of the metals silver (Ag), zinc (Zn), cadmium (Cd), or aluminum (Al):
The name of the metal element is used directly. The group number indicates the ion's charge.
Naming Non-Metals:
The non-metal becomes a negatively charged ion. The name is formed by dropping the element's ending and adding the suffix –ide.
Definitions
Unit Formula: The smallest, simplest ratio of ions that form a crystal of an ionic compound.
Cation: A positively charged ion. Examples:
ext{Na}^{1+} (sodium)
ext{Mg}^{2+} (magnesium)
ext{Zn}^{2+} (zinc)
Anion: A negatively charged ion.
Simple Anions
Element to Anion Name Conversion:
Fluorine - Fluoride: ext{F}^{1-}
Nitrogen - Nitride: ext{N}^{3-}
Chlorine - Chloride: ext{Cl}^{1-}
Phosphorus - Phosphide: ext{P}^{3-}
Bromine - Bromide: ext{Br}^{1-}
Arsenic - Arsenide: ext{As}^{3-}
Iodine - Iodide: ext{I}^{1-}
Carbon - Carbide: ext{C}^{4-}
Oxygen - Oxide: ext{O}^{2-}
Hydrogen - Hydride: ext{H}^{1-}
Sulfur - Sulfide: ext{S}^{2-}
Selenium - Selenide: ext{Se}^{2-}
Tellurium - Telluride: ext{Te}^{2-}
Additional Naming Rules for Binary Ionic Compounds
Metals Not in Group 1 or 2:
If the metal element is not in Group 1 or 2 and is not Ag, Zn, Cd, or Al:
The name of the metal is still used, but it must include a Roman numeral in parentheses to indicate the positive charge of the ion.
Charge Determination:
Metals outside Groups 1 or 2 can form multiple positive ions.
To find the charge of the positive ion, first determine the charge of the negative ion and then use Berzelius’ Rule to balance the charges. The total must equal zero in a compound.
Practice: Formula to Name
Li2O: Lithium oxide
AlCl3: Aluminum chloride
FeI3: Iron (III) iodide
PbBr4: Lead (IV) bromide
Na2S: Sodium sulfide
CuI2: Copper (II) iodide
Practice: Name to Formula
Barium fluoride: ext{BaF}_2
Tin (II) sulfide: ext{SnS}
Tin (IV) nitride: ext{Sn}3 ext{N}4
Iron (II) Oxide: ext{FeO}
Iron (III) Oxide (Rust): ext{Fe}2 ext{O}3
Lithium bromide: ext{LiBr}