Naming Compounds

A. Molecular

Molecular Names

Molecular Formulas

B. Ionic

Oxidation Numbers

Ionic Names

Ionic Formulas

C. Acids

Definition

Acid Names

Acid Formulas

Write the names of both elements.

Change the final ending to -ide.

Add prefixes to indicate subscripts.

Only use mono- prefix with oxide.

A. Molecular Names

PREFIX

mono-

di-

tri-

tetra-

penta-

hexa-

SUBSCRIPT

1

2

3

4

5

6

A. Molecular Names

CCl4

N2O

SF6

• carbon tetrachloride

• dinitrogen monoxide

• sulfur hexafluoride

A. Molecular Names

Write the more metallic element first.

Add subscripts according to prefixes.

A. Molecular Formulas

phosphorus trichloride

dinitrogen pentoxide

dihydrogen monoxide

• PCl3

• N2O5

• H2O

A. Molecular Formulas

The Seven Diatomic Elements

Br2 I2 N2 Cl2 H2 O2 F2

A. Molecular Formulas

B. Ionic Compounds

Oxidation Number = the charge on

an ion.

Indicates the # of e- gained/lost to

become stable.

1+

2+ 3+4+

4- 3- 2- 1-

0

Write the names of both elements,

cation (+) first.

Change the anion’s (-) ending to -ide.

Write the names of polyatomic ions.

For ions with variable oxidation #’s,

write the ox. # in parentheses using

Roman numerals. Overall charge = 0.

B. Ionic Names

NaBr

Na2CO3

FeCl3

• sodium bromide

• sodium carbonate

• iron(III) chloride

B. Ionic Names

Write each ion. Put the 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 #.

B. Ionic Formulas

potassium chloride

magnesium nitrate

copper(II) chloride

• K+ Cl- KCl

• Mg2+ NO3- Mg(NO3)2

• Cu2+ Cl- CuCl2

B. Ionic Formulas

calcium oxide

aluminum chlorate

iron(III) oxide

• Ca2+ O2- CaO

• Al3+ ClO3- Al(ClO3)3

• Fe3+ O2- Fe2O3

B. Ionic Formulas

Acid

• Compound that forms H+ in water.

• Formula usually begins with ‘H’.

Examples:

• HCl, HNO3, H2SO4

C. Acids

Anion Ending Acid Name

-ide hydro-(stem)-ic acid

-ate (stem)-ic acid

-ite (stem)-ous acid

C. Acid Names

HBr

H2CO3

H2SO3

• -ide

• -ate

• -ite

hydrobromic acid

carbonic acid

sulfurous acid

C. Acid Names

hydrofluoric acid

sulfuric acid

nitrous acid

• -ide

• -ate

• -ite

HF

H2SO4

HNO2

C. Acid Formulas