Naming Non-ionic Compounds

Rules to Live By

Rule #1

• The first element in the formula is named first, and the full element name is used.

Rule #2

• The second element is named as it would be if it was an anion.

– Ex. Cl would be “chloride” like before.

Rule #3

• Prefixes are used to tell the number of atoms in the formula.

– We will look at these in 2 more slides.

Rule #4

• The prefix mono- (meaning 1) is never used for the first element.

– Ex. CO2 is carbon dioxide, not monocarbon dioxide. Ever.

Prefixes

1 mono-

2 di-

3 tri-

4 tetra-

5 penta-

6 hexa-

7 hepta-

8 octa-

Yay Practice!

Name the following compounds:

1. PCl52. P4O6

3. SF6

4. SO3

5. SO2

6. N2O3

Phosphorus pentachloride

Tetraphosphorus hexoxide

Sulfur hexafluoride

Sulfur trioxide

Sulfur dioxide

Dinitrogen trioxide

Now go the other way!

• Give the formula for the following compounds!

1. Carbon pentasulfide

2. Diphosphorus hexachloride

3. Hexanitrogen monofluoride

4. Tetroxygen trichloride

5. Phosphorus pentachloride

CS5

P2Cl6

N6F O4Cl3

PCl5

Let’s Do Acid!In the learn-how-to-name-them sense…

Naming Acids1. If the anion does not contain oxygen,

the acid is named with the prefix hydro- and the suffix -ic.

Acid Anion Name .

HCl Cl-

HCN CN-

H2S S-2

hydrochloric acidhydrocyanic acid

hydrosulfuric acid

Naming Acids

2. When the anion contains oxygen, we add either –ic or –ous to the end.

-ic we use when we have an anion whose name ends in –ate:

Acid Anion Name .

H2SO4 sulfate

H3PO4 phosphate

HC2H3O2 acetate

sulfuric acid

phosphoric acid

acetic acid

Naming Acids

-ous we use when we have an anion

whose name ends in –ite.

Acid Anion Name .

H2SO3 sulfite

HNO2 nitrite

sulfurous acid

nitrous acid

Acid (starts with H and is not water)

The anion (-) name ends in…

-ide

Single element from the periodic table: Br, Cl, I, S…

“Hydro_______ic Acid”

-ite

Only polyatomic ions

“_____ous Acid”

-ate

Only polyatomic ions

“_____ic Acid”

(root)

(root)

(root)

Practice!

Name the following acids.

Acid Anion Name .

1. HF

2. H3PO3

3. HNO3

4. H2S

hydrofluoric acidF- (fluoride)

PO3-3 (phosphite) phosphorous acid

NO3- (nitrate) nitric acid

S-2 (sulfide) hydrosulfuric acid

The End

Now let’s do some more practice.