1. Chemical Nomenclature
Naming Compounds and Writing Formulas of Ionic, Covalent, Mixed, and Acidic Compounds

2. Naming Binary Ionic Compounds
Contain ONLY 2 ions
CATION (positive) written first
ANION (negative) written second
1. Give the cation its “regular” name
2. Give the anion its “root” name followed by the ending “-ide”
The ratio of ions as indicated by subscripts does not affect the name

3. Naming Binary Ionic Compounds
EXAMPLES
NaCl
SODIUM CHLORIDE
CaF2
CALCIUM FLUORIDE
K2S
POTASSIUM SULFIDE
Al2O3
ALUMINUM OXIDE

4. Naming Binary Ionic Compounds with Transition Metals
Cations of transition metals may have more than one possible charge
The charge of the cation of these transition metals depends on the anion it combines with
The charge of the transition metal is shown by a Roman numeral in parentheses after the name of the cation
The anion is named with the “-ide” ending

5. Naming Binary Ionic Compounds with Transition Metals
EXAMPLES
FeCl2
Iron (II) chloride
MnO2
Manganese (IV) oxide
Ni2S3
Nickel (III) sulfide
CuBr
Copper (I) bromide

6. Naming Compounds Containing Polyatomic Ions
A polyatomic ion is a group of covalently bonded atoms that acts as a single unit when forming compounds
The charge of the ion corresponds to the number of electrons gained or lost by the unit
Each polyatomic ion MUST be memorized (name, formula, and charge)
In compounds the name of the polyatomic ion is given as appropriate in the formula

7. Naming Compounds Containing Polyatomic Ions
EXAMPLES
NH4Cl
Ammonium chloride
KMnO4
Potassium permanganate
Cu(C2H3O2)2
Copper (II) acetate
Pb(SO4)2
Lead (IV) sulfate

8. Break

9. Writing Formulas of Ionic Compounds
The overall charge of an ionic compound is ZERO
Therefore, there must be an equal amount of POSITIVE and NEGATIVE charge
The ratio of CATIONS to ANIONS is such that the resulting formula reflects an overall neutral charge

10. Sr+2 I-1 SrI2 Writing Formulas of Ionic Compounds
Problem: Write the formula for strontium iodide
Step One: Write the symbols and charges for each ion
Sr+2
I-1
SrI2

11. Problem: Write the formula of copper (II) nitride
Writing Formulas of Ionic Compounds
Problem: Write the formula of copper (II) nitride
Cu+2 N-3
Cu3N2

12. Write the formula for sodium acetate
Writing Formulas of Ionic Compounds with Polyatomic Ions
Write the formula for sodium acetate
Na+1 C2H3O2-1
Since the charges are already EQUAL BUT OPPOSITE, you only need one of each ion in the formula.
NaC2H3O2

13. Write the formula for ammonium sulfide
Writing Formulas of Ionic Compounds
Write the formula for ammonium sulfide
NH4+1 S-2
(NH4)2S
Use parentheses when you need more than one of a polyatomic ion
The subscript outside the parentheses tell how many of this ion are needed

14. Write the formula for chromium (III) sulfate
Writing Formulas of Ionic Compounds
Write the formula for chromium (III) sulfate
Cr+3 SO4-2
Cr2(SO4)3
No parentheses for the Cr because it is not a polyatomic ion!

15. Practice

16. Naming Covalent Compounds Using the Prefix System
Binary covalent compounds typically contain two NONMETALS
In this system, prefixes are used to indicate the number of each atom present
No indication of charge or oxidation number is used in this system

17. Naming Covalent Compounds Using the Prefix System
Mono = 1
Di = 2
Tri = 3
Tetra = 4
Penta = 5
Hexa = 6
Hepta = 7
Octa = 8
Nona = 9
Deca = 10

18. Naming Covalent Compounds Using the Prefix System
EXAMPLES
CO2
Carbon dioxide (if there is only one atom of the first element do not use a prefix – at all other times a prefix must be used)
P2O5
Diphosphorus pentoxide
N2O3
Dinitrogen trioxide

19. Writing Formulas of Covalent Compounds
If named using the prefix system, indicate the number of each element with a subscript
EXAMPLE: Tetraphosphorus decoxide
P4O10
EXAMPLE: Dihydrogen monoxide
H2O

20. Types of Acids
Binary acids - contain the HYDROGEN cation (+1 charge) and a monatomic anion
Oxyacids - contain the HYDROGEN cation (+1 charge) and a polyatomic ion that contains oxygen.

21. Writing Formulas of Binary Acids
Binary acids contain the HYDROGEN cation (+1 charge) and a monatomic anion
Prefix of the name is “Hydro-”
Use the root of the anion
Suffix is “-ic”
Follow with the word “acid”
EXAMPLES
HCl is hydrochloric acid
H2S is hydrosulfuric acid
HF is hydrofluoric acid

22. Writing Formulas of Oxyacids
Oxyacids contain the HYDROGEN cation (+1 charge) and a polyatomic ion that contains oxygen.
Prefix corresponds to the prefix of the anion
The root is from the anion
Suffix is from the anion
End with the word “acid”

23. Writing Formulas of Oxyacids
Anion
Anion Name
Acid Prefix/Root
Acid Suffix
Acid Name
Acid Formula
SO2-2
Hyposulfite
Hyposulfur-
-ous
Hyposulfurous Acid
H2SO2
SO3-2
Sulfite
Sulfur-
Sulfurous Acid
H2SO3
SO4-2
Sulfate
-ic
Sulfuric Acid
H2SO4
SO5-2
Persulfate
Persulfur-
Persulfuric Acid
H2SO5

24. Writing Formulas of Oxyacids
EXAMPLES
Nitrous Acid
HNO2
Hypochlorous Acid
HClO
Perphosphoric Acid
H3PO5
Carbonic Acid
H2CO3