1. January 15, 2014 Brain Bender
What does the prefix “poly” mean? Considering that, what do you think a polyatomic ion is?

2. Naming Ionic Compounds with Polyatomic Ions
Complex Ionic Compounds

3. Polyatomic Ions: “Poly” – many/multiple/more than one
Polyatomic ions – ions that are made up with more than one atom
Examples: NO3-1 SO MnO C2H3O2-1
_These are compounds that act just like an individual element

4. Complex Ionic Compounds
Any ionic compound that contains three or more elements.
It can ONLY occur if there is a polyatomic ion present in the compound.

5. This is your list, please do not lose it

6. Let’s Practice: Identify the compounds with polyatomic ions:
Hint: Look for 3 or more different atoms in the compound.
NaCl
Co(CO3)2
Li2SO4
CsNO3
MgO
Cr3(PO4)2

7. Rules for naming Complex Ionic Compounds:
Name the first element directly off the periodic table, IF IT IS A METAL
*Remember to identify the charge of any transition metal using roman numerals
Name the second element, IF IT IS A NONMETAL, by changing the ending to -ide
If either of the elements is a polyatomic, name it directly off the polyatomic list, replacing step 1 or 2.
Na2CO3
Sodium Carbonate

8. Naming Complex Ionic Compounds:
Name the first element directly off the periodic table, IF IT IS A METAL
*Remember to identify the charge of any transition metal using roman numerals
Name the second element, IF IT IS A NONMETAL, by changing the ending to -ide
If either of the elements is a polyatomic, name it directly off the polyatomic list, replacing step 1 or 2.
NH4Cl
Ammonium Chloride

9. Naming Complex Ionic Compounds:
When we need multiple polyatomic ions to create a neutral compound, ( ) are used around the polyatomic ion.
The subscript is placed OUTSIDE of the ( )
The polyatomic ion MUST be treated as ONE atom….it is a unit that CANNOT be separated.
Ca ClO3-1
Ca(ClO3)2
Calcium Chlorate

10. Nonmetal (or polyatomic)
Let’s Practice:
Compound
Metal (or polyatomic)
Nonmetal (or polyatomic)
Compound Name:
NH4ClO3
Fe(NO3)2
Mg3(PO4)2
(NH4)2O
Mn(C2H3O2)3
Al(OH)3

11. Rules for writing compound formulas:
Write out the ions for each of the elements/polyatomic present
Write the charge with each ion present
Drop the signs (+/-)
Swap the numbers
Simplify if necessary
Sodium Phosphate
Na+1 PO4-3
Na3PO4

12. Here’s another example:
Write out the ions for each of the elements/polyatomic present
Write the charge with each ion present
Drop the signs (+/-)
Swap the numbers
Simplify if necessary
Aluminum Carbonate
Al+3 CO3-2
Al2(CO3)3

13. Let’s Practice: Compound Name Metal (or polyatomic) symbol and charge
Nonmetal (or polyatomic) symbol and charge
Compound
Beryllium Nitrate
Chromium (II) Hydroxide
Gallium Chlorate
Ammonium Carbonate
Zirconium (III) Sulfate