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LESSON 13

Naming Compounds
Chemical Nomenclature

• today the most common system is IUPAC for most chemicals

-ions
-binary ionic
-polyatomic ions
-molecular compounds
-hydrates
-acids/bases

A) Chemical Formulas

• *be aware* of the difference between the ion and compound formulas

     Zn - has a charge of 2+ (cations)
   BaCl2  - the 2 represents the number of ions
     Fe2S3   - iron (|||) sulfide * some transition metals may have more
                        than 1 ion the roman numeral tell what charge it is    

B) Multivalent Ions

• some elements can form more than one ion

eg. Iron -->   Fe 3-   or   Fe 2-
      Copper -->  Cu 3+   or   Cu 1+

• usually the top number (charge) is more commonly used
• IUPAC uses roman numerals in parenthesis to show the charge
• classical systems uses latin names of elements and the suffixes -ic (larger charge) and -ous (smaller charge)           

eg. Ferric Oxide  (iron)
      -  ic refers to the larger charge      Fe 3-   Fe  2+     -->   Fe 2 O 3      

Other classical names
 - Ferr - iron                      - Stann - tin
 - Cupp - copper               - Aunn - gold
 - Mercur - mercury          - Plumb - lead

C) Complex Ions    

• complex ions are larger groups of atoms that stay together during a chemical reaction
• almost all are anions
• write the metal name and the polyatomic ion name

eg.  sodium nitrate    NaNO3
       rubidium phosphate     Rb3PO4
       stannic nitride    Sn3N4        

D) Hydrates

• some compounds can form lattices that bond to water molecules
• copper sulfate  --> without the water molecule the compound
• sodium sulfate        is preceded 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 the prefix indicating the # of  water molecules (mono- 1, di- 2)
         3. add hydrate after prefix

eg. Ca(SO3)2 - 8H2O          -   calcium sulphite octahydrate
      Zn(NO3) -  4H2O          -   zinc nitrate tetrahydrate

E) Naming Acids and Bases
    
         - hydrogen compounds are acids
              - HCl --> hydrochloric acid
         - hydrogen appears first in the formula unless it is part of a polyatomic group

posted by chemistry11 @ 3:52 PM