Thursday, November 4, 2010

Naming Compounds

Chemical Nomenclature

-Today, the most common system is IUPAC for most elements like,


  1. Ions
  2. Binary Ionic
  3. Polyatomic Ions
  4. Molecular Compounds
  5. Hydrates
  6. Acids/Bases
Chemical Formulas

-Beware of the differences between Ion and Compound Formulas

Eg.


Zn^2+ (The 2+ means an Ion Charge)
BaCl2   (The 2 means the number of Ions)

Multivalent Ions

-Some elements can form more than one ion.
  -Eg. Iron > Fe^3+ or Fe^2+
  -Eg. Copper > Cu^2+ or Cu^1+
-The top number on the P.T. (Periodic Table) is more common
-IUPAC was uses roman numerals in parenthesis to show the charge
-Classical (i.e. Old) systems uses latin names of elements and the suffixes like '-ic' (larger charge) and '-ous' (smaller charge)
  -Eg. Ferric Oxide
            /\
      Refers to Iron (Fe)
      '-ic' refers to larger charge
      So iron's charge would be +3 not +2

Other Classical Names
-Ferr - Iron
-Cupp - Copper
-Mercur - Mercury
-Stann - Tin
-Aunn - Gold
-Plumb - Lead

Eg.  FeCl2 - Ferrous Chloride
       SnO2 - Stannic Oxide
       Pb(NO3)2 - Plumbous Nitrate

Hydrates

-Some compounds can form lattice that bond to water molecules

   -Copper Sulfate
   -Sodium Sulfate                                   Without water, the compounds is often preceeded by 'anhydrous'


-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, di, tri, tetra, penta etc..)
  3. Add hydrate after the prefix
Eg. Li(ClO4) 3H2O - Lithium Perchlorate Trihydrate

Molecular Compounds

-Write names of the following compounds

N2O4 - Dinitrate Tetraoxide

Naming Acids/Bases

-Hydrogen compounds are acids
   HCl > Hydrochloric acid

Naming Bases

-Caution and OH
   -NaOH - Sodium Hydroxide

No comments:

Post a Comment