1. 22.3 Notes Continued
Part C

2. Objectives
Write formulas and names for covalent compounds

3. Covalent compounds Made of just nonmetals Share electrons
Smallest piece is a molecule
Can’t be held together because of opposite charges
Can’t use charges to figure out how many of each atom

4. Covalent/Molecular compounds
Ionic compounds use charges to determine how many of each element.
Molecular compounds name tells you the number of atoms.
Uses prefixes to tell you the number

5. Naming Covalent Compounds
Prefix element name Prefix element name-ide
The last vowel of the prefix is dropped when the second element begins with a vowel as in pentoxide
No double vowels when writing names (oa oo)
Often the prefix mono- is omitted from the first element when naming
Many times it is also omitted from 2nd element, though it is used for emphasis in some cases

6. Examples Carbon dioxide – CO2 Dihydrogen monoxide – H2O
Dinitrogren pentasulfide – N2S5
Tricarbon tetrafluoride – C3F4

7. Name These
N2O
NO2
Cl4O7
NBr3
BaCl5

8. Writing formulas for Covalent Compounds
Simply write the chemical symbol
Subscript is derived from the prefix
Mono = 1, di = 2, tri = 3, ect

9. Write formulas for these
diphosphorus pentoxide
tetraiodide nonoxide
sulfur hexaflouride
Carbon tetrahydride
phosphorus trifluoride

10. Hydrates
An ionic compound that has water chemically attached to its ions and written into its chemical formula
Some ionic compounds have water molecules as part of their structure

11. Hydrates pg. 708
These same prefixes are used when naming the hydrates previously discussed.
The main ionic compound is named the regular way, but the number of water molecules in the hydrate is indicated by the Greek prefix.
Chemical formula • # H2O

12. In-Class Assignment/Homework
Finish naming Molecular Compounds WKT
22.3 Reinforcement WKT