1. Section 3 Writing & Naming Compounds
CHAPTER 19
Section 3
Writing & Naming Compounds

2. TLW write and name binary ionic compounds.
OBJECTIVES
TLW write and name binary ionic compounds.
TLW write and name polyatomic ionic compounds.

3. Materials Needed Today
Periodic table  for oxidation numbers
Polyatomic Ions Reference sheet

4. BINARY = 2 elements
POLYATOMIC = more than 2 elements

5. Write the name of the 1st element
NAMING BINARY IONIC
NaCl  Sodium Chloride
Write the name of the 1st element
Write the root of the 2nd element and add “-ide”

6. Try a couple…
MgO
Magnesium Oxide
LiBr
Lithium Bromide

7. Sodium Chloride Na is 1+ and Cl is 1- 1+ and 1- = 0  Stability NaCl
WRITING BINARY IONIC
Refer to Oxidation Numbers
Sodium Chloride
Na is 1+ and Cl is 1-
1+ and 1- = 0  Stability
NaCl

8. Try another…
CaF2  Calcium Fluoride (subscripts??? Where did those come from???)
Calcium has an oxidation number of 2+
Fluorine has an oxidation number of 1-
So, “cross” the oxidation numbers to make subscripts
Ca and F -1  CaF2

9. A couple more…
Calcium Nitride
Ca3N2
Barium Phosphide
Ba3P2

10. PRACTICE ACTIVITY Get up, move around, and “bond” with your classmates.

11. NAMING POLYATOMIC IONIC
CaCO3
Write the name of the 1st element
Use the Chart to write the name of the Polyatomic Ion
Calcium Carbonate

12. Try a couple…
HSO4
Hydrogen Sulfate
K2CO3
Potassium Carbonate

13. WRITING POLYATOMIC IONIC
Calcium Hydroxide
Write the 1st element  Ca
Use the chart for the Polyatomic Ion
Hydroxide  OH
Don’t forget oxidation numbers = subscripts!!!
Ca2+ and OH 1-
“cross” the oxidation numbers to make subscripts
Ca(OH)2 don’t forget parenthesis for the polyatomic

14. Practice a couple…
Magnesium Nitrate
Mg 2+
[NO3]- …chart
Mg(NO3)2

15. Always an exception… (discuss this more tomorrow)
Some elements may have more than 1 oxidation number
See Table 2 on page 588
Copper (I) and Copper (II)
Iron (II) and Iron (III)
Chromium (II) and Chromium (III)
Lead (II) and Lead (IV)
All are + ions, so they will be 1st in the compound

16. PRACTICE
TLW write and name binary ionic compounds.
TLW write and name polyatomic ionic compounds.
…tomorrow…write and name binary covalent…and practice, practice, practice…review, review, review
Balancing chemical equations