Lesson #3:Formulas & Names of

Ionic Compounds (Part One)

Naming Ionic Compounds

• When naming most Binary Ionic Compounds, we must follow these IUPAC rules:

1. Name the positive ion first by writing the full name of the metallic element

2. Name the non-metal ion next by dropping the last syllable(s) of the name of the element and adding the suffix “ide”

Figuring Out the Formula

• When writing the correct chemical formula for a Binary Ionic Compound, here are the IUPAC rules to follow:

1. Write the symbol of the metallic element first and the non-metal second

2. Determine the charge that each element will have when it forms an ion and write the element in ion notation

3. Balance the charges to get a combination that has ZERO total charge

4. Write the formulaEventually you should be able to do steps #2 and #3 in your head

Lesson #3:Formulas & Names of

Ionic Compounds (Part Two)

What is the name of the following compounds?

FeCl2FeCl3

Binary Ionic Compound Wrinkle #1

• Some Metals can have more than one different charge when they become ions

• The Common Ion Charge is the most likely possible charge that an element can have when it becomes an ion

• The Alternate Ion Charge (or Other Ion Charge) is the other possible charge that the element can have when it becomes an ion

Example: Consider Copper

292+

1+

Cu14.01

Common Ion Charge-means most of the time Copper will have a charge of +2

Alternate Ion Charge- Copper can also have a charge of +1

What are the possible charges for:Iron (Fe)

Tin (Sn)

Lead (Pb)

Mercury(Hg)

Gold (Au)

The Stock System

• Developed by German Chemist Alfred Stock in the 18th century

• A system used to name Binary Ionic Compounds with multi-valence metal ions

• A Roman Numeral representing the charge of the metal ion is inserted between the name of the metal ion and the name of the non-metal ion

Lesson #3:Formulas & Names of

Ionic Compounds (Part Three)

What?!

Mg3(PO4)2

Binary Ionic Compounds

Wrinkle #2:

Dealing with Polyatomic

Ions

• A Polyatomic Ion is an ion made up of more than one element

• When naming an Ionic Compound that contains a polyatomic ion follow these IUPAC rules:

1. Write the full name of the positive ion first

2. Write the full name of the negative ion second IF it is polyatomic (otherwise use the suffix –ide)

Note: The names and charges of several polyatomic ions are on the back of your periodic table

• When writing a chemical formula for an Ionic Compound that contains a polyatomic ion follow these IUPAC rules:

1. Write the symbol or formula for the positive ion first

2. Write the symbol or formula for the negative ion second