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}