Chem Class- October 2, 2009

Ah yes. Chemical Nomenclature. This is all about naming chemical compounds. Different systems have been used through the enturies but the most common system today is IUPAC (International Union of Pure and Applied Chemistry) for most chemicals.

• Ions
• Binary Ions
• Polyatomic Ions
• Molecular Compounds
• Acids

Be careful when dealing with superscripts and subscripts. Superscripts refer to the number that is beside and above the symbol, representing the ion charge while subscripts refer to the number that is beside and below the symbol, representing the number of ions.

The first two columns in the table below contain symbols with superscripts while the last column represents symbols with subscripts (look at the numbers).

You probably noticed the two terms: Cation and Anion. Cations are ions with positive charches while Anions are ions with negative charges.

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When it comes to naming ions, use the name of the element and then add ion for metals (Al3+ becomes Aluminum Ion) and simply remove the original ending and add -ide for non metals (F- becomes Fluoride).

Below is a table of polyatomic ions which have special names:

Here's a youtube video on how to write the formula for Binary Ionic Compounds. It's pretty good on listing the steps and providing a visual example of a lewis diagram for why the compound is written the way it is:

Some elements can form more than one ion and they are called Multivanet Ions. The more common ion is the top one of the Periodic Table. IUPAC uses Roman numerals in parenthesis to show the charge (I, II, III, IV, V, VI, VII)

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Finally, Classical Systems use Latin names of elements and the suffixes -ic for larger charges (Eg: FeO----->smaller charge-----> Ferrous Oxide) and -ous for smaller charges (Eg: Fe2O3----->larger charge----->Ferric Oxide)

Other Classical Names

Ferr-Iron

Cupp-Copper

Mercur-Mercury

Stann-Tin

Aunn- Gold

Plumb-Lead