Ionic Compounds
Review
What are binary ionic compounds?
What are multivalent metals?
What are polyatomic ions?
Are ionic compound electrolytes or non-electrolytes?
Binary Molecular
Compounds
We have already learned that binary = 2, therefore a
binary molecular compound is a molecular compound
containing only 2 elements.
Names for binary molecular compounds have two parts.
Three rules help name them:
The first element is usually farthest to the left on the
periodic table of the elements.
The suffix –ide is added to the end of the second element.
Prefixes are used to indicate how many atoms of each
element is present.
Ex: N2O4 is written as dinitrogen tetraoxide
Prefixes for Molecular
Compounds
Prefix
Number
Prefix
Number
mono-
1
hexa-
6
di-
2
hepta-
7
tri-
3
octa-
8
tetra-
4
nona-
9
penta-
5
deca-
10
NOTE: mono- is not used to describe the first element in a
compound; you only use mono- to describe the second element.
Ex: For CO2 you say carbon dioxide, not monocarbon
dioxide.
How does Hydrogen
break the rules?
HCl, though it looks ionic because H is in the metals
section of the periodic table, is molecular.
Hydrogen is technically a non-metal as it is gaseous at
room temperature.
Even though we know HCl is molecular, we name it
as though it is ionic: hydrogen chloride
Answer questions 9 and 10 on page 123 of Science10
Rules
Create a table in your notes which summarizes the
rules for naming compounds.
Think about things such as prefixes, suffixes,
multivalent metals, subscripts, etc.
Summary of Key naming and formula-writing rules:
Ionic
Molecular