SNC2D
Molecular Compounds
Learning Goals:
 Be able to name molecular (covalent) compounds and
explain the difference between molecular and ionic
Molecular Compounds:
Example:
Date:
Homework:

Worksheet
are usually composed of two or more different non-metals. The elements
within a molecular compound ________________ electrons (sharing is caring).
A water molecule with hydrogen and oxygen molecules share electrons. Draw a Lewis Dot
Diagram illustrating how hydrogen and oxygen share electrons so that both atoms are stable.
Molecular compounds feature covalent bonds between molecules and are often referred to as
______________ compounds.
Diatomic Molecules
Diatomic molecules are molecules composted of only two atoms of the same element (“di” = two).
These are molecular compounds (share electrons) and are often found this way naturally.
Examples:
Hydrogen (H2), Chlorine (Cl2), Nitrogen (N2), Oxygen (O2), Bromine (Br2), Iodine (I2), Fluorine (F2)
Naming Binary Molecular Compounds
A binary molecular compound is composed of 2 non-metals joined by one or more covalent bond.
Prefixes indicate the number of atoms of each element in a molecule of the compound.
Prefix
monoditritetra-
Number
1
2
3
4
Steps to name binary molecular compounds:
1. Use prefixes to indicate the number of both atoms in the compound (given in the formula)
2. The name of the second element ends in –ide. Write the elements in the order of how they appear in the
chemical formula
Note: if there is only 1 atom in the first element, you do not use the prefix “mono”.
Example:
Name P2O3
Name BrCl
e.g.1) Name the following molecular compounds.
a) N2O4 :___________________
b) SO3 :___________________
c) As2O3 :___________________
Writing Chemical Formulas for Molecular Compounds (going the other way)
1. Write down the symbol of the elements with the subscripts indicated by the prefixes.
DO NOT SIMPLIFY THE NUMBERS  it will change the compound! (e.g. NO2 vs N2O4)
Example:
Write the chemical formula for disulfur dinitride
Now You Try!
1. Name each of the following molecular compounds.
a) BrF :________________________________
e) PBr5 :________________________________
b) NO :________________________________
f) Br2O :________________________________
c) CO2 :________________________________
g) P2O3 :________________________________
d) SO3 :________________________________
h) P4O10 :________________________________
2. Write the chemical formula for each of the following molecular compounds.
a) Iodine monofluoride :_________________
e) Carbon tetrafluoride :__________________
b) Arsenic trichloride :__________________
f) Dichlorine monoxide :__________________
c) Sulfur dioxide :______________________
g) Sulfur hexafluoride :___________________
d) Phosphorus pentabromide :____________
h) Hydrogen monochloride :_______________