1. Binary Molecular Compounds:
Compounds made by two different nonmetals.
Examples:
CO2
HBr
P2O5

2. Naming Binary Molecular Compounds:
1)The first element in the formula is
always named first, using the entire
element name.
2) The second element in the formula is
named using the root of the element
& adding the suffix –ide.
3) Prefixes are used to indicate the
number of atoms of each type that
are present in the compound.

3. Prefixes # of atoms
Mono one
Di two
Tri three
Tetra four
Penta five
Hexa six
Hepta – seven
Octa eight
Nona nine
Deca ten

4. Naming Binary Molecular Compounds:
EXAMPLES:
N2O5 –
H2O --
N2O --
CO2 --
PCl5 --
SO3 --
NH3 --
dinitrogen pentoxide.
dihydrogen monoxide.
dinitrogen monoxide.
carbon dioxide.
phosphorus pentachloride.
sulfur trioxide.
nitrogen trihydride.

5. Writing Formulas (Molecular Compounds):
1) Write the element symbols in the same
order than it appears in the compound name.
2) Use subscripts to represent the number of
atoms of each element indicated by the
prefixes used.
Dinitrogen tetroxide
Dihydrogen monoxide
Diphosphorus monoxide ----
Carbon monoxide
Phosphorus trichloride -----
N2O4
H2O
P2O CO
PCl3

6. Practice:
1) CCl4----
2) Phosphorus tribromide –-
3) CO -----
4) Dichlorine pentoxide ----
5) HI(g) ---
6) Hydrogen chloride---
Carbon tetrachloride.
PBr3
Carbon monoxide.
Cl2O5
Hydrogen iodide.
HCl(g)

7. II - Write the formulas of the following:
Dinitrogen tetroxide
Dihydrogen monoxide
Diphosphorus monoxide ----
Carbon monoxide
Phosphorus trichloride -----
III - Write the names or the formulas for:
1) CCl4----
2) Phosphorus tribromide –-
3) CO -----
4) Dichlorine pentoxide ----
5) HI(g) ---
6) Hydrogen chloride---