Chemical Nomenclature October 2, 2009

In the beginning of the class, we quickly went over what electrolysis was, and were even showed a little live example; two wires were connected and plugged in and once they both had contact of a pickle in acid it showed the flow of electrolysis. Afterwards, we went over our homework questions (Pg. 76 #1,2,4 & Pg. 79 #1-4), then went straight into learning/reviewing our next chapter of naming chemical compounds.

Chemical Nomenclature:

-Different systems have been used throughout the centuries to help pack down naming chemical compounds considering they are a very difficult task.

- Today, the most common system is IUPAC for most chemicals.

• Ions
• Binary Ionic
• Polytomic Ions
• Molecular Compounds
• Acids

Chemical Formulas:
Be aware of the differences between ion and compound formulas.

Zn(2+) <----- Ion Charge BaCl 2 <----- Number of Ions

Naming Ions:
- When naming metals, use the name of the element and add ION
Example: Al (3+) = Aluminum Ion

- When naming non-metals, remove the original ending and add -IDE
Example: F - = Fluorine ---> Fluoride

- Reminder: Polyatomic ions have special names

Binary Ionic: (Steps)

1) Write the formula for the cation (positive) first, and then the formula for the anion (negative)
Example:
Lead (IV) Sulphide ------> Pb (4+) S(2-)

2)By moving the numbers below, it'll show a criss-cross
Example:
Pb(4+) S(2-) -----> Pb2S4

3) Don't forget to reduce the ion numbers to their lowest common multiples - as well as omitting 1 and the chargers. If you don't, you will lose half a mark.

Example:
Pb2S4 ------> Pb1S2 ------> PbS2

More Examples:

Aluminum Fluoride ---> AlF3
Sodium Oxide ---> Na2O
Iron (III) Sulphide ---> Fe2S3

**NOTE: Metals that have more than one ion is called a transition metal. To identify the number, look at that charge. **

Multivalent Ions:
-Multivalent ions are elements that can form more than one ion.
Examples:
Iron ---> Fe (3+) or Fe (2+)
Copper ---> Cu (2+) or Cu (1+)

-The more common ion are seen on the top of the Periodic Table.
- Roman numerals are used by the IUPAC and are kept in parenthesis to show the charge.
-Classical (old) systems uses latin names of elements and the suffixes -ic (larger charge) and - ous (smaller charge)
Examples:
FeO ---> Ferrous Oxide
Fe2O3 ---> Ferric Oxide

Other Classical Names:

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

Chemical Formula:
Sodium Nitrate = NaNO3
Barium Phosphate = Ba3(PO4)2

Below is an example of how to write an ionic compound.



Homework: 7-1 Practice Problems & 7-1 Apply worksheet ; omit #3 on 7-1 apply

(Rachelle Flores' blog entry)