Covalent Compounds
Formula to Name
Definition
Covalent bond atoms share electrons
Binary Covalent Compound
compound made from two non-metals
that share electrons
Non
Non
metal
metal
Non
Non
metal
metal
Covalent compound
Binary Covalent Compounds
Identifying & Naming Binary
Covalent
• These compounds have:
– 2 elements (“binary”)
– Both non-metals (“covalent”)
• To name these compounds:
– Write the name of the first element with the
prefix indicating the number of atoms (except
don’t use “mono-”)
– Write the name of the second element with the
prefix indicating the number of atoms
(including “mono-”) and the suffix “ide”
1
Covalent Prefixes
Example #10
The Appendix of your book (Page A-2) has the following chart
PREFIXES USED IN MOLECULAR COMPOUNDS
1. mono2. di3. tri4. tetra5. penta6. hexa7. hepta8. octa9. nona10. deca-
Example #10
P2O5
Example #11
2 = “di-”
Phosphorus
P2O5
SiO2
Oxygen
5 = “penta-”
Use “-ide”
Diphosphorus pentaoxide
2
Let’s Practice
Example #11
Don’t use “mono-” on
first element
CO2
Silicon
SiO2
Example:
Write the name
for the following
compounds
N2O4
P4O10
Oxygen
2 = “di-”
Use “-ide”
CO
Silicon dioxide
Let’s Practice
Example:
Write the name
for the following
compounds
CO2
Carbon dioxide
N2O4
Dinitrogen tetraoxide
P4O10
Tetraphosphorus decaoxide
CO
Carbon monoxide
Nomenclature Summary
Naming Chemical
Formulas
Starts with a metal or
NH4
2 capital letters =
Binary Ionic
Does not contain a
metal = Binary
Covalent compound
More than 2 elements
= Polyatomic Ionic
3
Mixed Practice
Mixed Practice
Na2O
Example:
Write the name
for the following
compounds
Na2O
Sodium oxide
K3PO4
Potassium phosphate
Cu(OH)2
Cu(OH)2
Copper (II) hydroxide
(NH4)2S
(NH4)2S
Ammonium sulfide
MgCl2
MgCl2
Magnesium chloride
K3PO4
Example:
Write the name
for the following
compounds
Identifying & Naming Binary
Covalent
• These compounds:
– Use covalent prefixes
Covalent Compounds
Name to Formula
• To write these formulas:
– Write the symbols of the first and second
element
– Use the covalent prefixes (assume the first
element is “1” if there’s no prefix) as the
subscripts to show number of atoms.
Atoms do not form charges when bonding covalently…you DO NOT
need to worry about charges with this type!
4
Example #7
Example #7
“Di-” = 2
N
Dinitrogen Tetraoxide
Dinitrogen Tetraoxide
O
“Tetra-” = 4
N2O4
Example #8
Example #8
“Mono-” is not written for
the first element
Si
Silicon dioxide
Silicon dioxide
O
“Di-” = 2
SiO2
5
Let’s Practice
CAUTION!!!
“di” and “bi” do not mean the same thing!
Carbon monoxide
di-
bi-
Stands for “2” in covalent
compounds
Means there’s a hydrogen in
the polyatomic anion
Carbon dioxide = CO2
Sodium biphosphate =
Na2HPO4
Nitrogen dioxide
Diphosphorus pentaoxide
Let’s Practice
Example:
Write the
following
chemical
formulas
Example:
Write the
following
chemical
formulas
Nomenclature Summary
Carbon monoxide
CO
Nitrogen dioxide
NO2
Diphosphorus pentaoxide
Writing Chemical
Formulas
P2O5
Does not contain
covalent prefixes
Ends with “-ide”
(except hydroxide &
cyanide) = Binary Ionic
Does contain covalent
prefixes = Binary
Covalent compound
All others = Polyatomic
Ionic
6
Mixed Practice
Mixed Practice
Magnesium hydroxide
Example:
Write the
following
chemical
formulas
Magnesium hydroxide
Mg(OH)2
Copper (II) nitrate
Cu(NO3)2
Iron (III) oxide
Iron (III) oxide
Fe2O3
Nitrogen dioxide
Nitrogen dioxide
NO2
Sodium bicarbonate
Sodium bicarbonate
NaHCO3
Copper (II) nitrate
Example:
Write the
following
chemical
formulas
7