(DA) Nov. 3, 2010: Naming Compounds

Chemical Nomenclature

• Today the most common system IUPAC for most chemicals
  - Ions
  - Binary Ionic
  - Polyatomic ions
  - Molecular Compounds
  - Hydrates
  - Acids / Bases

Chemical Formulas

Be aware of the differences between ion and compound formulas

 - Zn^2+ <------------------------- Ion Charge

 - BaCl2 <------------------------ Number of Ions

Multivalent Ions

• Some elements can form more than one ion
  eg. Iron -> Fe^3+ or Fe^2+
        Copper -> Cu^2+ or Cu^1+
• IUPAC uses Roman Numerals in parenthesis to show the charge
• Classical systems use latin names of elements ans suffixes
  - ic (larger charge) and -ous (smaller charge)
  
  Example:
  - Ferric Oxide -------------> Iron (Fe)
   [ -ic refers to larger charge
     -ous refers to smaller charge]

• Ferr - Iron
• Cupp - Copper
• Mercur - Mercury
• Stann - Tin
• Aunn - Gold
• Plumb - Lead

Complex Ions

• Complex ions are larger groups of atoms that stay together during a chemical reactions
• Almost all are anions
• Write the metal name and the polyatomic ion

Hydrates

• Some compounds can form latices that bound to water molecules
  - Copper Sulphate
  - Sodium Sulfate
• These crystals contain water inside them which can be released by heating.

To name hydrates

1. Write the name of the chemical formula
2. Add a prefix indicating the number of water molecules (mono=1, di=2, tri=3 etc.)
3. Add hydrate after the prefix

ie. CuSO₄·5H₂O          Copper (II) Sulphate Penta Hydrate

      LiClO₄·3H₂O          Lithium Perchlorate Tri Hydrate

Naming Acids And Bases

• Hydrogen Compounds are acids
  - HCl ---> Hydrochloric Acid
  - H₂SO₄ --> Sulfuric Acid
• Hydrogen appears first in the formula unless it is part of a polyatomic group
  - CH₃COOH --> Acetic Acid