Naming Covalent
Compounds
Objectives:
1. The name for covalent compounds with given formula
2. Give a formula for covalent compounds with given name
Covalent Cmpds
• Made of 2 anions (2 negatively charged ions)
• Identify the less EN element of the two (left and down—
decreases)
• The 1st nonmetal is given the name on the PT
• The second changes the ending to –ide…don’t change
polyatomic
• Never use “criss-cross” to balance
• Use prefixes to show how many of each element are need
• Number
• Prefix
• 1
•
Mono
• 2
•
Di
• 3
•
Tri
• 4
•
Tetra
• 5
•
Penta
• 6
•
Hexa
• 7
•
Hepta
• 8
•
Octa
• 9
•
Nona
• 10
•
Deca
Using prefixes
• Never use if the first element only has one
Practice
SO2
sulfur dioxide
N2O
dinitrogen monoxide
NO2
nitrogen dioxide
CCl4
carbon tetrachloride
Cl2O7
dichlorine heptaoxide
PCl3
phosphorus trichloride
SF6
sulfur hexafluoride
Si3N4
trisilicon tetranitride
N(BrO3)5
nitrogen pentabromate
H2O
water 
•
•
•
•
•
•
•
•
Phosphorus trioxide
Dinitrogen pentacarbide
Tellurium noniodide
Carbon monoxide
Selenium heptafluoride
Tetraphosphorous decoxide
Arsenic hexabromide
Silicon dichloride
PO3
N2C5
TeI9
CO
SeF7
P4O10
AsBr6
SiCl2