Analía Bellizzi – Chemistry Classes

Ronald Reagan Senior High School

Naming Ionic compounds

Nomenclature is a set or system of names.  The nomenclature that we use in chemistry is based on the IUPAC (International Union of Pure and Applied Chemists) . The following simplified rules can be used to name the most of inorganic compounds.

Naming Simple Ionic Compounds: 

 

  1. The names of ionic compounds are derived from the positive ions and the negative ions in the compound.
  2. The positive ion or part is always named first and written first in formulas. 
  3. If the metal is in the transition metals zone, it has to show the oxidation number (charge) between parentheses. 

Binary Compounds
(only 2 elements form the compound)

Binary Ionic Compounds (only 2 elements form the compound)

When naming ionic compounds

  • The cation (+) retains the same name as the element.
  • The anion’s (-)name is similar to the elemental name, but the ending of the name has been removed and replaced with “ide.”
  • If a metallic element has cations of different charges, the cation’s oxidation number or valence, has to be indicated by Roman numerals in parentheses after its name in writing (the Stock system).

Depending on the elements forming the compound and their properties, we can classify Ionic compounds as:

The metal will not change the name, the non metal will get the suffix “IDE”

  • Basic Oxides = Metal + Oxygen → Name: Metal(ox#) Oxide 
    • Examples:
      • Na2O = sodium oxide
      • MgO  = magnesium oxide
      • FeO   = Iron (II) Oxide
      • Cu2O = Copper(I) oxide
  • Peroxides = Metals + Oxygen → Name: Metal(ox#) Peroxide 
    • Examples:
      • Na2O2   = Sodium Peroxide
      • K2O2     = Potassium peroxide
      • Mn2O2  = Manganese (II) peroxide
  • Binary Salts = Metal + Non-metal → Name: Metal(ox#) Non-Metal-IDE 
    • Examples:
      • NaCl   = Sodium Chloride
      • KBr     = Potassium Bromide
      • FeCl3  = Iron (III) chloride
      • MnS= Manganese (II) Sulfide

More complex compounds

  • More complex Ionic Compounds (More than 2 elements form the compound) Most of the time one or 2 polyatomic ions are involved. 

    When naming ionic compounds

    • The cation (+) retains the same name as the element.
    • The anion’s (-)name is the correspondent to the polyatomic ion name.
    • If a metallic element has cations of different charges, the cation’s oxidation number or valence, has to be indicated by Roman numerals in parentheses after its name in writing (the Stock system).
  •  Oxo- Salts = Metal + polyatomic ion →Name: Metal(ox#) Polyatomic ion
    • Examples:
      • NaNO3  = Sodium Nitrate
      • Rb2SO4    = Rubidium Sulfate
      • CuCO3  = Copper (II) Carbonate
      • Pb(CH3COO)2= Lead (II) Acetate

         

  • Ammonium- Salts (I)= Ammonium + Non Metal →Name: Ammonium Non-Metal-IDE 
    • Examples:
      • NH4Cl   = Ammonium Chloride
      • (NH4)2S     = Ammonium Sulfide

 

  • Ammonium- Salts (II)= Ammonium + Polyatomic Ion →Name: Ammonium Polyatomic Ion Name 
    • Examples:
      • NH4NO3   = Ammonium Nitrate
      • (NH4)2SO4     = Ammonium Sulfate
      • NH4CH3COO= Ammonium acetate