Chapter 6.3 Notes
1. Naming
a. The
Ionic Compounds
name of an ionic compound must
distinguish the compound from other
ionic compounds containing the same
elements.
b. The formula of an ionic compound
describes the ratio of the ions in the
compound.
2.
Binary Ionic Compounds
a. A compound
made from only two
elements is a binary compound.
b. The pattern for naming binary
ionic compounds is the cation
followed by the name of the anion.
i.The name for the cation is the
name of the metal without any
changes while the name of the
anion uses part of the name of the
nonmetal with the suffix –ide at
the end.
3.
Metals With Multiple Ions
a.
When a metal forms more than
one ion, the name of the ion
contains a Roman numeral to
indicate the charge on the ion.
b.
Ex.1) Copper(I) Oxide VS.
Copper(II) Oxide
i. The chemical formula for
copper(I) oxide is Cu2O because
it takes two Cu1+ ions to balance
the charge on an O2- ion.
ii. The chemical formula for
copper(II) oxide is CuO
because it takes only one
Cu2+ ion to balance the
charge on an O2- ion.
4.
Polyatomic Ions
A covalently bonded group of
atoms that has a positive or
negative charge and acts as a unit
is a polyatomic ion.
b. The prefix poly means many.
a.
c.
Ex. 2) Iron(III) Hydroxide
i. Chemical formula = Fe(OH)3,
The parentheses and subscript 3
indicates that there are three
hydroxide ions for each iron
(III) ions.
5.
Writing Formulas for Ionic
Compounds
If you know the name of an ionic
compound, you can write its formula.
b. Place the symbol of the cation first,
followed by the symbol of the anion.
a.
Use subscripts to show the ratio of
the ions in the compound.
d. Because all compounds are
neutral, the total charges on the
cations and anions must add up to
zero.
c.
e.
Ex. 3) Sulfur and Sodium
i. There must be two sodium ions
(Na+) for each sulfide ion (S2-). The
formula for sodium sulfide is Na2S.
The 2- charge on one sulfide ion is
balanced by the 1+ charges on two
sodium ions.
What Do I Know?
The name of the compound is
calcium chloride.
What Do I Need To Know?
The chemical formula for calcium
chloride.
Plan and Solve:
1. List the symbols and charges
for the cation and anion.
 Ca with a charge of 2+ and Cl
with a charge of 1-.
2. Determine the ratio of ions in
the compound.
 It takes two 1- charges to
balance the 2+ charge. There
will be two chloride ions for
each calcium ion.
3. Write the formula for
calcium chloride.
CaCl2
What Do I Know?
The name of the compound is
calcium oxide.
What Do I Need To Know?
The chemical formula for calcium
oxide.
Plan and Solve:
1. List the symbols and charges
for the cation and anion.
 Ca with a charge of 2+ and O
with a charge of 2-.
2. Determine the ratio of ions in
the compound.
 It takes one calcium ion with a
charge of 2+ to balance one
oxide ion with a charge of 2-.
Answer:
3. Write the formula for
calcium oxide.
 CaO
What Do I Know?
The name of the compound is
Copper(I) sulfide.
What Do I Need To Know?
The chemical formula for
copper(I) sulfide.
Plan and Solve:
3. Write the formula for calcium
1. List the symbols and charges
chloride.
for the cation and anion.
 Cu2S
 Cu(I) with a charge of 1+ and
Sulfide with a charge of 22. Determine the ratio of ions in
the compound.
 Two copper(I) ions, each with
a charge of 1+ , balance one
sulfide ion with a charge of 2-.
What Do I Know?
The name of the compound is
Sodium Sulfate.
What Do I Need To Know?
The chemical formula for Sodium
Sulfate.
Plan and Solve:
1. Write the formula for sodium
1. List the symbols and charges
sulfate.
for the cation and anion.
 Na2SO4
 Sodium with a charge of 1+
and sulfate with a charge of 2-.
1. Determine the ratio of ions in
the compound.
 Two sodium ions, each with a
charge of 1+, balance one
sulfate ion with a charge of 2-.
6.
Describing Molecular Compounds
In naming molecular compounds the
focus is on the composition of
molecules.
b. The name and formula of a molecular
compound describe the type and
number of atoms in a molecule of the
compound.
a.
c.
d.
e.
In naming molecular compounds the most
metallic element appears first in the name.
These elements are farther to the left and
bottom of the periodic table.
You first must add the proper prefix to each
element. The prefix tells us how many
atoms of each element there are.
The name of the second element ends in
ide. Such as Carbon Dioxide.
Number of Atoms
Prefix
1
2
3
4
5
6
7
8
9
10
MonoDi
TriTetra
Penta
Hexa
Hepta
Octa
NonaDeca
Name the compound N2O4.
• There are two nitrogen atoms
and four oxygen atoms.
Therefore the name is dinitrogen
tetraoxide.
Name the compound NO2.
• There is one nitrogen atom and two
oxygen atoms. Therefore the name
is mononitrogen dioxide. However
the prefix mono- is generally not
used, therefore the name is nitrogen
dioxide.
Write the formula for diphosphorus
tetrafluoride.
• Since di- means two and tetra
means four the formula is P2F4.