1. Before I’m done taking roll…
Place your notebooks OPENED to the 5.1 “Binary Ionic Compounds” notes and worksheet on the TA’s desk
Obtain a blank ½ sheet of paper from the front counter
Put your Name, Date, and Period at the top of the ½ sheet of paper
Number your ½ sheet from 1 to 14, skipping a line between each.

2. Homework Assessment Write the name or formula of each:
Li+
Cr2+
Ag+
O2-
KBr
Fe2O3
ZnS
strontium ion
iron (III) ion
cadmium ion
nitride ion
lithium sulfide
cobalt (II) phosphide
silver oxide

3. Polyatomic Ionic Compounds (or Ternary Ionic Compounds)
Chemistry
Unit 5: Nomenclature
5.2

4. Objectives
Write the names of polyatomic ionic compounds from their formulas
Write the chemical formulas of polyatomic ionic compounds from their names

5. Classification of Compounds
Binary Ionic: 2 types of atoms (cation and anion) IONIC BONDING
Polyatomic Ionic: (Ternary) 3 or more types of atoms (cation and anion) IONIC BONDING
Binary Molecular: 2 types of atoms (both non- metals) COVALENT BONDING
Acids: Contain Hydrogen and often oxygen USUALLY COVALENT BONDING

6. Polyatomic Ions
Groups of atoms that stay together and have an overall charge, and one name.
Usually end in –ate or –ite

7. Check Your Golden Sheet
Sulfate: SO Sulfite: SO32—
Carbonate: CO32—
Chromate: CrO42–
Dichromate: Cr2O72—
: NH41+

8. Polyatomic ions are… Acetate: Nitrate: Nitrite: Permanganate: MnO41-
Hydroxide: OH1-
Cyanide: CN1-

9. To Write the Name of a Compound Containing a Polyatomic Ion
Write the name of the cation (most likely a metal)
Determine if the cation will need Roman Numerals (is it a Transition Metal other than Ag, Zn, or Cd?)
Write the parentheses for the Roman Numerals but don’t fill in just yet
Write the name of the anion (either a non-metal ending in –ide, or get the name from the Golden Sheet!)
If Roman Numerals are needed, determine the charge on the cation by the total charge of the anions (either figure out the charge using your PT or look up the charge on the Golden Sheet)

10. Example iron (III) silicate Fe2(SiO3)3 Fe is “iron”
Iron is a transition metal and will need Roman Numerals
iron ( )
SiO3 (on the Golden Sheet) is called “silicate” so now we have: iron ( ) silicate
The charge on a silicate ion is 2– and there are three of them in the formula, so the total negative charge is 6– this means that the total positive charge must be 6+. This is distributed over “two” iron atoms, so each iron atom must have a charge of 3+.
iron (III) silicate

11. Naming Polyatomic Compounds
Ca(NO3)2
Co(C2H3O2)2
K2SO4
Fe(CN)2

12. Writing Formulas for Compounds with Polyatomic Ions
Determine the formulas AND CHARGES for both the cation and the anion using the PT or the Golden Sheet
Determine how many of each ion you need in order for the total charges to balance out
Write the formula. Remember to use parentheses if more than one polyatomic ion is needed.

13. Example aluminum peroxide Aluminum = Al3+ (from PT)
peroxide = O22– (from Golden Sheet)
It will take “two” Al3+ ions and “three” O22– ions to balance the overall charges
So… Al2(O2)3

14. Formulas of Polyatomic Compounds
aluminum acetate
sodium phosphate
zinc hydroxide
ammonium carbonate
copper (II) nitrite

15. Please Write Your Summary and Questions Now