(2.2) MOLECULAR COMPOUNDS
(p130-131)
Naming and all that.
Molecular Compounds
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Molecular compounds are formed by
combining two non-metals.
They do so by “sharing” electrons.
The bond formed by sharing electrons
is called a covalent bond.
Properties of Molecular
Compounds
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Often soft, liquid, solid or gas.
If they dissolve in water, they form
solutions that do no conduct electricity.
Tend to have relatively low melting
points.
Naming Molecular Compounds
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Naming molecular compounds is
different than naming ionic compounds
because non-metals can combine in
many different ways.
Naming Molecular Compounds
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Eg. carbon and oxygen can combine 2
different ways!!!
carbon monoxide CO
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carbon dioxide
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CO2
Naming Molecular Compounds
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To name a molecular compound
prefixes are used to show the number
of each type of atom.
Prefix system
Prefix
Number
mono
1
di
2
tri
3
tetra
4
penta
5
hexa
6
hepta
7
octa
8
nona
9
deca
10
Examples
name
formula
sulfur trioxide
dihydrogen monosulfide
SiO2
CF4
N2O5
disulfur dinitride
Examples
name
formula
sulfur trioxide
SO3
dihydrogen monosulfide
H2S
silicon dioxide
SiO2
carbon tetrafluoride
CF4
dinitrogen pentoxide
N2O5
disulfur dinitride
S2N2
NOTE: never have 2 vowels in a row between the
prefix and element ex: 2 “o’s” monooxide
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Naming Molecular Compounds
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A molecular compound has a two-part name:
first
Non-metal
Uses prefix for
number
Keeps its name
second
Non-metal
Uses prefix for
number
Changes ending to “ide”
Common Molecular
Compounds
You must know these….
 H2O
water
 H2O2
hydrogen peroxide
 CH4
methane
 CO2
carbon dioxide
Practice
-Video to recap!
-Do:
Worksheet 2.2 (C) - NAMING MOLECULAR
COMPOUND PRACTICE
-Quiz-Molecular Compounds next class
TEST UNIT 1-Part A on THURSDAY!
Classwork
Workbook
- 46-48
- 50-52
 Worksheet 2.2 (D)-naming ALL!
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 REMINDER:
TEST UNIT 1-Part A on THURSDAY, FEB 23