Ionic Nomenclature
D.1 Intro: Elements, Compounds
and Nomenclature
• Chemical nomenclature: the organized
system used to name substances and write
their chemical formulas.


Chemical formula: represents the number
of each kind of atom bonded together in a
substance.
Subscript: indicates the number of atoms
or ions present in the formula.
D.1 Intro: Elements, Compounds
and Nomenclature
Example (formula for water):
D.2
The History of Chemical
Nomenclature
• Lavoisier’s system of nomenclature is
sometimes called the Classical System.
This system of naming is used to the present
day.
Common Name
Systematic Name
fixed air
carbon dioxide
cinnabar
mercuric sulfide
D.2
The History of Chemical
Nomenclature
• Chemical formulas of compounds…
are written using two or more symbols
side by side.
use subscripts to make the formulas more
compact.
Example: carbon dioxide
Dalton formula:
Berzelius formula: CO2
D.2
The History of Chemical
Nomenclature
• Many elements form several compounds
with another given element.
Lavoisier’s Classical System was modified to
include suffixes to name these compounds:
Examples:
ferric oxide Fe2O3
ferrous oxide FeO
(More will be said on this in Section D.6.)
D.2
The History of Chemical
Nomenclature
Examples:
Chemical
Formula
Classical
System
Stock
System
FeCl2
ferrous chloride
iron(II) chloride
FeCl3
ferric chloride
iron(III) chloride
FeO
ferrous oxide
iron(II) oxide
Fe2O3
ferric oxide
iron(III) oxide
D.3
Classification of Compounds
• Ionic compounds are formed when
oppositely charged ions are attracted to
each other.
Strong electrostatic attractions.
High melting point and boiling point solids.
Capable of dissolving in water.
D.3
Classification of Compounds
• Cations are positively-charged ions.
Examples:
Na+, K+, Ca2+, Al3+, Fe3+

Anions are negatively-charged ions.
Examples:
Cl–, F–, S2–, Se2–, P3–
D.3
Classification of Compounds
• Molecular compounds are pure substances
composed of atom groupings called
molecules.
strong covalent bonds between atoms
 atoms share electrons
 each atom has a noble-gas electron arrangement
possess weak bonds between molecules
low melting point and boiling point gases,
liquids and solids
D.4 Binary Ionic Compounds
 Molecular Formula:
 Chemical formula for molecular substances.
 The actual number of each kind of atom
present in the molecule.

Empirical Formula:

Indicates the simplest whole number ratio of
atoms or ions in the compound.
D.4 Binary Ionic Compounds
• Naming Binary Ionic Compounds
 When naming any ionic compounds, simply
write the name of the positive ion followed
by the name of the negative ion.
 The rules for naming simple ions were given
in Unit B.
D.4 Binary Ionic Compounds
1. Name the cation by writing the full
name of the metallic element.
 Na+ is a sodium ion
 Zn2+ is a zinc ion
 Al3+ is an aluminum ion.
2.
Name the anion by abbreviating the full
name of the nonmetallic element and
adding –ide.



Cl– is a chloride ion
S2– is a sulfide ion
P3– is a phosphide ion
D.4 Binary Ionic Compounds
Examples:
 NaCl {from Na+Cl–}
sodium chloride
Sodium chloride is table salt.
 CaCl2 {from Ca2+(Cl–)2}
calcium chloride
Calcium chloride is a drying agent also used
to melt ice.
D.4 Binary Ionic Compounds
• Writing Chemical Formulas for Binary
Ionic Compounds
1. When given the name of the ionic
compound, first write the symbols for the
ions involved.
2. Next, determine the lowest whole number
ratio of ions that will provide an overall net
charge of zero.
(Criss-Cross)
D.4 Binary Ionic Compounds
Examples:
D.4 Binary Ionic Compounds
Examples:
D.4 Binary Ionic Compounds
Examples: