1. Naming Binary Molecular Compounds
2 elements
covalent bond

2. 3 Rules to Name
1. Name the first element using the entire name 2. Second element in the formula- use the root word and end in –ide ex: Oxygen Sulfur Hydrogen
Oxide
Sulfide
Hydride

3. 3. Add a prefix to both words to indicate the number of atoms
mono hexa-
di hepta-
tri octa-
tetra nona-
penta deca-

4. 2 Exceptions to the rule
1. When the formula contains one atom of the first element, omit mono ex: CO2
Carbon Dioxide
Not: Monocarbon Dioxide

5. 2 Exceptions to the rule
2. Drop the final letter in the prefix if the element begins with a vowel - For prefixes 1 & 4-10 ex: CO
Carbon monoxide
Not: Carbon monooxide

6. Example 1
S4N2
tetra di
sulfur
nitride
nitrogen
tetrasulfur
dinitride

7. Example 2 SO3 tri oxygen sulfur tri oxide Only one atom of sulfur
- so no prefix needed
oxygen
sulfur
tri
oxide

8. Example 3
P4S5
penta
tetra
sulfur
tetra
phosphorus
penta
sulfide

9. Example 4 CO mono oxygen NOT monooxide carbon mon oxide
Only one atom of carbon
- so no prefix needed
oxygen
NOT monooxide
carbon
mon
oxide

10. Example 5 NH3 tri hydrogen More Common Name is “ammonia” nitrogen tri
Only one atom of nitrogen
- so no prefix needed
hydrogen
More Common Name is “ammonia”
nitrogen
tri
hydride

11. Example 6 CH4 tetra hydrogen More Common Name is “methane” carbon
Only one atom of carbon
- so no prefix needed
hydrogen
Saturated has all H’s (single bonds), unsaturated is missing H’s from the presence of at least one single bond. Saturated is solid at room temp (butter) and not generally good for you (increases bad cholesterol) typically animal fats. Unsaturated is typically liquid at room temperature and a better alternative for you, typically vegetable fats.
More Common Name is “methane”
carbon
tetra
hydride

12. Example 7-9 Example 7: As2O3 diarsenic trioxide Example 8: N2O5
dinitrogen pentoxide
Example 9: P4O10
tetraphosphorus decoxide