Naming
Covalent
Compounds
So easy…
a monkey
can do it!!!
Compound
Is it ionic or covalent?
Ionic
Covalent
Is there a polyatomic group?
Name using prefixes
Have the combining
capacities been reduced?
Do you need Roman
Numerals for those with more
than one combining capacity
Naming Covalent
Compounds
A covalent Compound is formed when
bonding occurs between a non-metal and a
non-metal.
Unlike ionic bonding, the electrons are
shared.
Like ionic bonding, the reason the bonds are
formed is because the outer shell will be full
which is more like a noble gas.
Consider the following reaction form
hydrogen gas ( an element):
H⋅ + ⋅H → H :H
Each Hydrogen
atom now has two
electrons around it
The shared
electrons
pair is a
Covalent Bond
Naming Covalent Molecules
• The name gives us the #s of atoms of
each element in the compound
• Use prefixes to indicate how many
atoms there are of each type.
mono = 1
di = 2
tri = 3
tetra = 4
penta = 5
hexa = 6
hepta = 7
octa = 8
deca = 10
• Use the ending (-ide) for the second
element listed in the formula.
Naming Rules
• 1. Name the 1st element in the formula
• 2. Name the 2nd element, ending with “ide”
• 3. Add a prefix to each element’s name to
indicate the # of atoms of each element
• -Exceptions:
– If 1st element has 1 atom, DON’T add a prefix
– The prefix “mono” becomes “mon” if used
before “oxide”
Naming covalent compounds
N2O5
CO2
CO
SiO2
ICl3
P2O5
CCl4
dinitrogen pentoxide
carbon dioxide
carbon monoxide
silicon dioxide
iodine trichloride
diphophorous pentoxide
carbon tetrachloride
The rule may be modified to improve how a
name sounds.
Example - use monoxide not monooxide.
Write the formula for the
following covalent compounds
1. Carbon monoxide
2. Oxygen diflouride
3. Nitrogen tribromide
4. Calcium bromide
Name the following covalent
compounds
1. SiO2
2. N2O5
3. CCl4
4. IF7
A note on acids
• When an acid is dissolved in water, we
start with “hydro” and add an “ic” ending
• HF(aq) = hydrofluoric acid
• HCl(aq) = hydrochloric acid
• HBr(aq) = hydrobromic acid
Number prefixes:
•
mono-
1
hexa-
6
•
di-
2
hepta-
7
•
tri-
3
octa-
8
•
tetra-
4
nona-
9
•
penta-
5
deca-
10