Naming CompoundsObjectives:1. Name ionic and covalent compounds based off

of chemical formulas.2. Give a chemical formula based on a chemical

name.

Oxidation Numbers• The charge of an ion• # of electrons gained or lost• Only in ionic compounds• Cation—positive• Anino--negative

How to name Ionic Compounds• Write the name of both elements, cation first• Change the anion’s ending to –ide• Write the name of the polyatomic ion• If an ion has various oxidation numbers

(transitional metals), write the oxidation number in parentheses using roman numerals. (I, II, III, IV, V, VI, VII, VIII, IX, X)

Ionic compounds• NaBr• Sodium bromide

• NaCl• Sodium chloride

• CaCl• Calcium chloride

• FeCl3• Iron (III) chloride

Ionic Formulas• Write each ion. Put cation first• Overall charge must equal zero.• If charges cancel, just write the symbols• If not, crisscross the charges to find subscripts

• Use parentheses when more than one polyatomic ion is needed.

• Roman numerals indicate the oxidation number

Give the Formula• Potassium chloride• Magnesium bromide• Copper (II) chloride• Calcium oxide• Iron (III) oxide

Common Polyatomic Ions• Ammonium

• NH4+

• Hydronium• H3O+

• Bicarbonate• HCO3

-

• Cyanide• CN-

• Hydrogen sulfate• HSO4

-

• Hydroxide• OH-

• Nitrate• NO3

-

• Nitrite• NO2

-

More…• Perchlorate

• ClO4-

• Permanganate• MnO4

-

• Carbonate• CO3

2-

• Chromate• CrO4

2-

• Dichromate• Cr2O7

2-

• Hydrogen phosphate• HPO4

2-

• Sulfate• SO4

2-

More…• Sulfite• SO3

2-

• Thiosulfate• S2O3

2-

• Phosphate• PO4

3-

Naming Ionic Compounds with Polyatomic Ions

• Na2CO3

• Na2SO4

• Calcium nitrate• Magnesium nitrate• Aluminum chlorate