1. Chemical Names and Formulas

2. Monatomic Ions Cations
Groups 1A, 2A, 3A charges = group number
Name: element name “ion”
Examples:
Na+ sodium ion
Mg2+ magnesium ion
Al3+ aluminum ion

3. Common Cations

4. Monatomic Ions Anions Group A element charges = 8 - group number
Name: stem of element name + ide
Examples
Cl- chloride
S2- sulfide
O2- oxide
N3- nitride

5. Monatomic Ions Transition Metals (Group B)
Charges can’t be predicted from Periodic Table
Some are “multivalent”
Form more than one ion
Name: element name (charge) “ion”
“Stock” naming system
Use Roman numerals to indicate charge
Examples: Stock name Classical name
Fe2+ iron (II) ion ferrous ion
Fe3+ iron (III) ion ferric ion
Cu+ copper (I) ion cuprous ion
Cu 2+ copper (II) ion cupric ion

6. Ionic Charges of Representative Elements

7. Multivalent Cations

8. Polyatomic Ions Group of covalently bonded atoms that has a net charge
Most are anions
Oxyanions contain oxygen
End in –ate or –ite
SO42- sulfate SO32- sulfite
NO3- nitrate NO2- nitrite

9. Common Anions

10. Chloroxyanions Polyatomic ions containing oxygen and chlorine Formula
Name
ClO-
hypochlorite
ClO2-
chlorite
ClO3-
chlorate
ClO4-
perchlorate

11. Polyatomic Ions Some begin with hydrogen
H+ + CO32- → HCO3- hydrogen carbonate
“bicarbonate”
H+ + PO43- → HPO42- hydrogen phosphate
“biphosphate”
H+ + HPO42- → H2PO4- dihydrogen phosphate

12. Polyatomic Cations
Ammonium Ion NH4 +
H+ + :NH3 → NH4 +

14. 9.3 Naming and Writing Formulas for Molecular Compounds
Molecular compounds are named using a system of prefixes to indicate the number of each element in the compound
Do not use mono- before the first element
Example: SF6 sulfur hexafluoride
Example N2O4 dinitrogen tetroxide

16. 9.4 Formulas and Names of Acids & Bases
Acids are compounds that have one or more ionizable hydrogens
General formula HnX
HCl (g) + H2O → H3O+ + Cl- (aq)

17. Common Acids

19. Names & Formulas for Bases
Bases are compounds which produce the hydroxide ion when dissolved in water
NaOH (s) → Na+ (aq) + OH- (aq)
NH3(g) + H2O → NH4+ (aq) + OH- (aq+
Name as you would ionic compounds

20. Law of Definite Proportions
aka Law of Constant Composition
For any compound, the percent composition by mass is always the same
A given compound always contains elements in exactly the same proportion by mass
E.g. percent composition of water by mass is 11.1% H and 88.9% O regardless of how much or how little there is
An ice cube and an iceberg have the same % composition.

21. Law of Multiple Proportions
When two elements form different compounds, the mass of one element combining with the same mass of the other element occur in small whole number ratios
H2O2
H2O
Mass O
32 g
16 g
Mass H
2 g
Ratio O:H
16:1
8:1
Ratio O:O
16:8 = 2:1

22. Flow Chart to Name Chemical Compounds
This flowchart will help you name chemical compounds. Begin with the letters Q and R in the general formula Qx Ry. Q and R can be atoms, monatomic ions, or polyatomic ions.