Naming Molecular Compounds
Neutral
Element
Hydrogen
Anion
Name
Hydride
Ionic
Charge
-1
H1-
Carbon
Carbide
-1 or -4
C22- or C4-
+1 to +4
-1 to -4
di=2
Nitrogen
Nitride,
Azide
-3, -1/3
N3-, N31-
+1 to +5
-1 to -3
tri=3
Phosphorus
Phosphide
-3
P3-
+3, +5
-3 to +5
tetra=4
Oxygen
Oxide,
Peroxide
-2 or -1
O2- or O22-
+2
penta=5
Sulfur
Sulfide
-2
S2-
+4, +6
-2 to +6
hexa=6
Selenium
Selenide
-2
Se2-
+4, +6
-2 to +6
hepta=7
Fluorine
Fluoride
-1
F1-
Never +
octa=8
Chlorine
Chloride
-1
Cl1-
+5, +7
-1 to +7
nona=9
Bromine
Bromide
-1
Br1-
+5, +7
-1 to +7
deca=10
Iodine
Iodide
-1
I1-
+5, +7
-1 to +7
*******
© T. M. Chipi, chemistry instructor
Anion
Formula
Other
Oxidations
+1
Prefix
mono=1
Rules
1. Keep the first non-metal’s name unchanged.
*Use these rules to name compounds of metalloids*
2. Change the ending to –ide for the second non-metal in
the compound. The names of all binary molecular
compounds end with –ide just like the names of all binary
ionic compounds.
3. Use a prefix in front of the elements’ names to show
how many atoms of each element are present. {N4O10;
tetranitrogen decoxide}
4. Do not use mono if there is just one atom of the FIRST
(non-metal) element listed. {CO; carbon monoxide}
This rule has changed to never using the prefix mono when
there is just one atom of each non-metal. {CO; carbon
oxide}
5. Drop the vowel at the end of a prefix (except for i's) if
the element’s name begins with a vowel (i.e. pentoxide,
triiodide).
6. When writing the formula, the prefix is used as the
subscript of the element in the formula; the subscript is
written to the right of the element’s chemical symbol. (i.e.
carbon dioxide = CO2)
1
Naming Molecular Compounds
Name and write the chemical formula of the molecular compounds that result from the following chemical combinations.
1 oxygen
1 carbon
Carbon monoxide
Give oxidation # of
CO
both elements.
+2 -2
1 oxygen
2 nitrogen
2 oxygen
2 sulfur
4 chlorine
4 bromine
2 oxygen
3 oxygen
5 oxygen
4 hydrogen
2 oxygen
3 oxygen
4 fluorine
6 fluorine
2 chlorine
3 hydrogen
3 chlorine
5 chlorine
5 bromine
3 iodine
1 sulfur
1 phosphorus
Name these molecular compounds using the correct prefixes. State the oxidation number of both elements in the compound.
SiO2
Silicon dioxide
+4
-2
S2Cl2
NO2
OF2
P2 O5
P4O10
NF3
S2 O4
XeF4
NH3
Cl2O
Cl2O7
BCl3
B2H6
NO
© T. M. Chipi, chemistry instructor
NH3
Cl2O8
S2 O6
Cl2O P2O3 Cl2O7 BCl3 P2O3
2