1. Chemical Formulas
Chapter 5, pages

2. Chemical Formulas
Chemical formula - a symbolic representation of chemical compounds; contains:
elements in compound (symbols)
# of atoms in each element
NaCl – sodium-one atom & chlorine-one atom
H2O – Hydrogen-2 atoms & oxygen-one atom

3. Types of Chemical Formula
Ionic
Giving and Taking of Electrons
Covalent
Share of electrons

4. Types of Chemical Formulas
Ionic – metal and non-metal → transfer of electrons (e-)
Cation – lose e-, + charge (metals)
Anion – gain e-, - charge (non-metals)
H+ is the exception to this rule!
H – acts like a metal – has + charge

5. Types of Ions
There are two types on Ions
Monatomic
Polyatomic

6. Monatomic Ions Ions that are composed of only one element
Some elements may only form 1 ion
Examples
H+ (Hydrogen Ion)
Cl- (Chloride Ion)
Li+ (Lithium Ion)
Some Elements may form 2 or more ions
Cu+ Copper(I) or Cuprous Ion
Cu2+ Copper(II) or Cupric Ion

7. Common Monatomic Cations
1+ Charge
2+ Charge
3+ Charge
Hydrogen H+
Barium Ba2+
Aluminum Al3+
Potassium K+
Calcium Ca2+
Chromium Cr3+
Lithium Li+
Cobalt(II) Co2+
Iron(III) Fe3+
Sodium Na+
Copper(II) Cu2+
Cesium Cs+
Iron(II) Fe2+
Silver Ag+
Lead Pb2+
Copper(I) Cu+
Magnesium Mg2+

8. Common Monatomic Anions
1- Charge
2- Charge
3- Charge
Bromide Br-
Oxide O2-
Nitride N3-
Fluoride F-
Sulfide S2-
Chloride Cl-
Iodide I-

9. Types of Ionic Compounds
There are 2 types of Ionic compounds:
Binary Ionic Compounds
Ternary Ionic Compounds

10. Naming Binary Ionic Compounds
monoatomic + monoatomic (one atom + one atom)
1 cation (+) anion (-)
Examples
zinc oxide
Zn + O= ZnO
magnesium chloride
Mg + Cl= MgCl2
aluminum oxide
Al + O= Al2O3
Naming Binary Ionic Compounds
Begin with name of Cation
Normally elements name
End with name of Anion
Normally has –ide or –ate ending
If cation has multiple charges, you must indicate using roman numerals (Stock Naming System)

11. Polyatomic Ions
Polyatomic Ions are ions that are composed of two or more different elements
Again you have
Positive Polyatomic Ions=
Negative Polyatomic Ions=
We will only talk about one positive polyatomic ion which is ammonium ion (NH4+1)

12. Common Monatomic Anions
1- Charge
2- Charge
3- Charge
Acetate
Carbonate O2-
Phosphate PO43-
Bicarbonate HCO3-
Chromate CrO42-
Phosphite PO33-
Chlorate ClO3
Dichromate Cr2O72-
Cyanide CN
Oaxlate C2O42-
Nitrate N03
Sulfite SO32-
Nitrite NO2
Sulfate SO42-
Hydroxide OH-

13. Ternary Ionic Compounds
Compounds that contain 3 or more ions
One must be a polyatomic ion
Cation + Polyatomic Anion = Ternary Ion
Examples
Potassium Nitrate
K + NO3= KNO3
Naming Ternary Ionic Compounds
Begin with name of Cation
Normally elements name
End with name of Anion
Normally has –ide or –ate ending

14. Writing Binary and Ternary Formulas
Name
Cation
Anion
Equation
Sodium Chloride
Iron(III) Oxide
Iron(II) Nitrate
Copper(II) Sulfate

15. What about the Roman Numerals
Two Different Naming Systems
Stock System
Roman Numerals refer to Charge of the Cation or Anion
Newer, for the Lazy and Underachievers
Traditional System
-ous or –ic Ending
Older, for the sophisticated and over achievers

16. Traditional vs. Stock Cation Traditional Name Stock Name Fe 3+ Cu 2+
Pb 4+
Point is to be careful when using the traditional and stock ways
Stock May be more useful to you
Traditional is important to know for MSDS