Nomenclature of
Inorganic Compounds
Chapter 6
Hein and Arena
Version 1.1
Eugene Passer
Chemistry Department
1
Bronx Community College
© John Wiley and Sons, Inc
Chapter Outline
6.1 Common and Systematic 6.4 Binary Compounds
Names
6.5 Naming Compounds
6.2 Elements and Ions
Containing Polyatomic Ions
6.3 Writing Formulas from
Names of Compounds
6.6 Acids
2
Common and
Systematic Names
Chemical nomenclature is the system of
names that chemists use to identify
compounds. Two classes of names exist:
common names and systematic names.
3
• Common names are arbitrary names.
 They
are not based on the composition
of the compound.
 They are based on an outstanding
chemical or physical property.
 Chemists prefer systematic names.
 Systematic names precisely identify the
chemical composition of the compound.
 The
present system of inorganic
chemical nomenclature was devised by
the International Union of Pure and
Applied Chemistry (IUPAC).
4
5
Elements and Ions
The formula for most elements
is the symbol of the element.
Sodium
Potassium
Zinc
Argon
Mercury
Lead
Calcium
Na
K
Zn
Ar
Hg
Pb
Ca
6
Diatomic Molecules
These 7 elements are found
in nature as diatomic molecules.
Hydrogen
Nitrogen
Oxygen
Fluorine
Chlorine
Bromine
Iodine
H2
N2
O2
F2
Cl2
Br2
I2
7
Polyatomic Elements
Two elements are commonly polyatomic.
Sulfur
Phosphorous
S8
P4
9
Ions
charged
known
as an ion
IfAone
or moreparticle
electrons
are removed
from a
can be
or A
neutral
atomproduced
a positivebyionadding
is formed.
removing
ora cation.
more electrons
positive
ion isone
called
from a neutral atom.
remove e-
→
neutral atom
cation
10
Ions
Two types
- Cations – From loss of electrons
- Anions – From the gain of electrons
11
IfA one
or more
electrons
are removed
from
charged
particle
known
as an ion
acan
neutral
a positive
is formed.
be atom
produced
byionadding
or A
positive
ion isone
called
removing
or a cation.
more electrons
from a neutral atom.
remove e-
→
neutral atom
cation
12
Positive Ion Formation:
Loss of Electrons From a Neutral Atom
Na  Na+ + e-
Ca  Ca2+ + 2eAl  Al3+ + 3e-
13
Naming Cations
Cations are named
as their parent atoms.
the
same
14
Atom
Cation
Name of
Cation
sodium (Na)
+
Na
sodium ion
15
Atom
Cation
Name of
Cation
calcium (Ca)
2+
Ca
calcium ion
16
Atom
Cation
Name of
Cation
lithium (Li)
+
Li
lithium ion
17
Atom
Cation
Name of
Cation
magnesium (Mg)
2+
Mg
magnesium ion
18
Atom
Cation
Name of
Cation
strontium (Sr)
2+
Sr
strontium ion
19
If
one or more
electrons
areas
added
to a
A charged
particle
known
an ion
neutral
a negative
ion is formed.
A
can beatom
produced
by adding
or
negative
is called
an anion.
removingion
one
or more
electrons
from a neutral atom.
add e-
neutral atom
→
anion
20
Naming Anions
An anion consisting of one element has the
stem of the parent element and an –ide
ending
21
Atom
Anion
Name of
Anion
fluorine (F)
F
stem
fluoride ion
22
Atom
Anion
Name of
Anion
chlorine (Cl)
Cl
stem
chloride ion
23
Atom
Anion
Name of
Anion
bromine (Br)
Br
stem
bromide ion
24
Atom
Anion
Name of
Anion
nitrogen (N)
3N
stem
nitride ion
25
Atom
Anion
Name of
Anion
phosphorous (P)
3P
stem
phosphide ion
26
Atom
Anion
Name of
Anion
oxygen (O)
2O
stem
oxide ion
27
Naming Anions
Ions are always formed by adding or
removing electrons from an atom.
28
Naming Anions
Most often ions are formed when metals
combine with nonmetals.
29
Naming Anions
The charge on an ion can be predicted from
its position in the periodic table.
30
Naming Anions
elements
elements of
elements
elements
of of of
elements of Group
VIA have
a
Group IIA have Group
a Group
VAGroup
have
VIIA
a have
a
IA have a +1 charge
-2 charge
+2 charge
-3 charge
-1 charge
31
The charge on a main-group (U.S. A group) ion
corresponds to its group number:
Group
1A
2A
3A
5A
6A
7A
Charge
1+
2+
3+
3–
2–
1–
Writing Formulas From
Names of Compounds
A chemical compound must have a
net charge of zero.
33
Writing Formulas From
Names of Compounds
If the compound contains ions,
then the charges on all of
the ions must add to zero.
34
Write the formula of calcium chloride.
Step 1. Write down the formulas of the ions.
Ca2+ ClStep 2. Combine the smallest numbers of Ca2+
- so that the sum of the charges
and
Cl
The cation
Theisanion is
equals
written
written
first. zero.
second.
(Ca2+) + 2(Cl-) = 0
(2+) + 2(1-) = 0 The lowest
common multiple
The correct formula is CaCl2
of +2 and –1 is 2
35
Write the formula of barium phosphide.
Step 1. Write down the formulas of the ions.
Ba2+ P3Step 2. Combine the smallest numbers of Ba2+
and P3- so that the sum of the charges
The cation
The anion
is
is
equals zero.
written
written
first. second.
3(Ba2+) + 2(P3-) = 0
3(2+) + 2(3-) = 0 The lowest
common multiple
The correct formula is Ba3P2
of +2 and –3 is 6
36
Write the formula of magnesium oxide.
Step 1. Write down the formulas of the ions.
Mg2+ O2Step 2. Combine the smallest numbers of Mg2+
and O2- so that the sum of the charges
equals zero.
(Mg2+) + (O2-) = 0
(2+) + (2-) = 0The lowest
common multiple
The correct formula is MgO
of +2 and –2 is 1
37
Binary Compounds
Binary compounds contain
two different elements.
only
38
Binary Compounds
Binary ionic compounds consist of a metal
combined with a non-metal.
39
Binary Compounds
A. Binary Ionic Compounds Containing a
Metal Forming Only One Type of Cation
40
Binary Compounds
• The chemical name is composed of the
name of the metal followed by the name
of the nonmetal which has been
modified to an identifying stem plus the
suffix –ide.
• Using this system the number of atoms
of each element present is not expressed
in the name.
41
Name of Metal
+ Stem of Nonmetal
plus -ide ending
42
43
Name the Compound CaF2
Step 1 From the formula it is
a two-element compound and
follows the rules for binary
compounds.
44
Name the Compound CaF2
Step 2 The compound is
composed of Ca, a
metal, and F, a nonmetal. Ca
forms only a +2 cation. Thus,
call the positive part of the
compound calcium.
45
Name the Compound CaF2
Step 3 Modify the name of
the second element to the
stem fluor- and add the binary
ending –ide
to form the name of the
negative part, fluoride.
46
Name the Compound CaF2
Step 4 The name of the
compound is therefore
calcium fluoride.
47
Examples
Compound
NaCl
name of metal
Name
sodium
chloride
nonmetal stem
48
Examples
Compound
MgCl2
name of metal
Name
magnesium
chloride
nonmetal stem
49
Examples
Compound
K2O
name of metal
Name
potassium
oxide
nonmetal stem
50
Examples
Compound
Na3P
name of metal
Name
sodium
phosphide
nonmetal stem
51
Binary Compounds
B. Binary Ionic Compounds Containing a Metal
That Can Form Two or More Types of Cations
52
Name the Compound FeS
Step 1 This compound
follows the rules for a
binary compound.
53
Name the Compound FeS
Step 2 ItInissulfides,
a compound
the
of
Fe, aon
metal,
and S, a
charge
S is –2.
nonmetal.
Fe charge
is a
Therefore the
on
transition metal that has
Fe must be +2, and the
more than one type of
name
of
the
positive
cation.
part of the compound
is iron (II).
54
Name the Compound FeS
Step 3 We have already
determined that the name
of the negative part of the
compound will be sulfide.
55
Name the Compound FeS
Step 4 The name of FeS
is iron(II) sulfide.
56
The Stock System
The metals in the center of the periodic
table (including the transition metals) often
form more than one type of cation.
57
Each ion of iron forms a different
compound with the same anion.
Fe2+
FeS
Fe3+
Fe2S3
58
InIUPAC
the Stock
System
charge
on of
the cation
devised
the the
Stock
System
is nomenclature
designated bytoa name
Roman
numeral placed
in
compounds
of
parentheses
following
theofname
metals thatimmediately
have more than
one type
of cation.
the metal.
Cation
Charge
+1
+2
+3
+4
+5
Roman
Numeral
I
II
III
IV
V
The nonmetal name ends in -ide.
59
Stock System
Lower
Lower Charge
Charge
Element
Formula
Higher
HigherCharge
Charge
Name
Formula
Name
Copper
Cu+
copper (I)
Cu2+
copper (II)
Iron
Fe2+
iron(II)
Fe3+
iron(III)
Lead
Pb2+
lead (II)
Pb4+
lead(IV)
Mercury
Hg22+
mercury(I)
Hg2+
mercury(II)
Tin
Sn2+
Tin(II)
Sn4+
Tin (II)
60
Examples
iron(II) chloride
FeCl2
+2
iron(II)
-1
chloride
compound
ion
ioncharge
name
name
iron(III) chloride
FeCl3
+3
iron(III)
-1
chloride
61
Examples
tin(II) bromide
SnBr2
+2
tin(II)
-1
bromide
compound
ion
ioncharge
name
name
tin(IV) bromide
SnBr4
+4
tin(IV)
-1
bromide
62
The Classical System
In the Classical System the name of the metal
(usually the Latin name) is modified with the
suffixes -ous and ic.
63
The Classical System
Metal name ends in
-ous lower charge
-ic higher charge
nonmetal name ends in
-ide
64
Examples
ferrous chloride
FeCl2
+2
ferrous
-1
chloride
ion
compound
ioncharge
name name
ferric chloride
FeCl3
+3
ferric
-1
chloride
65
Examples
stannous bromide
SnBr2
+2
stannous
-1
bromide
compound
ion
ioncharge
name
name
stannic bromide
SnBr4
+4
stannic
-1
bromide
66
Ion Names: Classical System
Lower Charge
Higher Charge
Element
Formula
Name
Formula
Name
Copper
Cu+
cuprous
Cu2+
Cupric
Iron
Fe2+
ferrous
Fe3+
ferric
Lead
Pb2+
plumbous
Pb4+
plumbic
Mercury
Hg
mercurous
Hg2+
mercuric
Tin
Sn
stannous
Sn4+
stannic
2+
2
2+
67
Binary Compounds Containing
Two Nonmetals
Compounds between nonmetals are
molecular, not ionic.
68
Binary Compounds Containing
Two Nonmetals
In a compound formed between two
nonmetals, the element that occurs first in
this series is named first.
 Si
I
B
 Br
P
N
H
 Cl
C
O
69
S
F
Prefixes
A Greek prefix is placed before the name of
each element to indicate the number of
atoms of the element that are present.
70
Prefixes
Mono is rarely used when
naming the first element.
• mono = 1

di = 2

tri = 3
 tetra = 4
 penta = 5
 hexa = 6
 hepta = 7
 octa = 8
 nona = 9
 deca = 10
71
Examples
dinitrogen trioxide
N2 O 3
indicates two
nitrogen atoms
indicates three
oxygen atoms
72
Examples
phosphorous pentachloride
PCl5
indicates one
phosphorous atom
indicates five
chlorine atoms
73
Examples
dichlorine heptaoxide
Cl2O7
indicates two
chlorine atoms
indicates seven
oxygen atoms
74
Determine the Name of PCl5
Step 1
• There are 2 elements present.
• The compound is binary.
• Phosphorous and chlorine are nonmetals so the
rules for naming
nonmetals apply.
• Phosphorous
binary
is named
compound is a chloride.
compounds
first.
of
Therefore
2
the
75
Determine the Name of PCl5
Step 2
 No prefix is needed for phosphorous because
each molecule of PCl5 has only one phosphorous
atom. The prefix penta- is used with chloride
because there are 5 chlorine atoms present in
one molecule.
Step 3
 The name is phosphorous pentachloride.
76
Examples
Cl2O3
dichlorine trioxide
77
Examples
N2O3
dinitrogen trioxide
78
Examples
CCl4
carbon tetrachloride
79
Examples
CO
carbon monoxide
80
Examples
Name CO2
carbon dioxide
81
Examples
Name PI3
phosphorous triiodide
82
D. Acids Derived
from Binary Compounds
83
D. Acids Derived
from Binary Compounds
Certain binary hydrogen compounds, when
dissolved in water, form solutions that have
acid properties.
• The aqueous solutions of these
compounds are given acid names.
• The acids names are in addition to their
–ide names.
• Hydrogen is typically the first element
of a binary acid formula.
84
D. Acids Derived
from Binary Compounds
Acid Formation
binary hydrogen
compound (not
an acid).
water
acid
85
D. Acids Derived
from Binary Compounds
Pure compound
HCl
-ide
Dissolved in water
HCl
acid
86
D. Acids Derived
from Binary Compounds
• To name binary acids write the symbol
of hydrogen first.
• After hydrogen write the symbol of the
second element.
• Place the prefix hydro- in front of the
stem of the nonmetal name.
• Place the suffix -ic after the stem of the
nonmetal name.
87
Examples
Pure Compound
HCl
hydrogen chloride
88
Examples
Dissolved in Water
HCl
hydrochloric acid
89
Examples
Pure Compound
HI
hydrogen iodide
90
Examples
Dissolved in Water
HI
hydroiodic acid
91
Examples
Pure Compound
H 2S
hydrogen sulfide
92
Examples
Dissolved in Water
H 2S
hydrosulfuric acid
93
Examples
Pure Compound
H2Se
hydrogen selenide
94
Examples
Dissolved in Water
H2Se
hydroselenic acid
95
96
Naming Compounds
Containing Polyatomic Ions
A polyatomic ion is an ion that
contains two or more elements.
NO
3
97
Naming Compounds
Containing Polyatomic Ions
• Compounds containing polyatomic ions are
composed of three or more elements.
• They usually consist of one or more cations
combined with a negative polyatomic ion.
Na 2CO3
98
Naming Compounds
Containing Polyatomic Ions
 When naming a compound containing a
polyatomic ion, name the cation first
and then name the anion.
Na 2CO3
99
This is the way the
formula is written.
KMnO 4
K
+
MnO
4
The ions are what is
actually present.
100
This is the way the
formula is written.
Na 2CO3
2Na
+
CO
23
The ions are what is
actually present.
101
Prefixes and Suffixes
Elements that Form More than One
Polyatomic Ion with Oxygen
102
Anions ending in -ate always contain
more oxygen than ions ending in -ite.
nitrite
2
NO
nitrate
3
NO
103
Anions ending in -ate always contain
more oxygen than ions ending in -ite.
phosphite
33
PO
phosphate
34
PO
104
Anions ending in -ate always contain
more oxygen than ions ending in -ite.
sulfite
23
SO
sulfate
24
SO
-ate and –ite do not indicate
the number of oxygen atoms.
105
per- denotes anions with more oxygen
than the -ate form.
chlorate
3
ClO
perchlorate
4
ClO
106
hypo- denotes anions with less oxygen
than the -ite form.
hypochlorite
-
ClO
chlorite
2
ClO
107
108
Four ions do not use the –ate/ite system.
hydroxide
-
cyanide
-
hydrogen sulfide
-
peroxide
22
OH
HS
CN
O
109
There are three common
charged polyatomic ions.
positively
mercury(I)
2+
2
Hg
hydronium
+
3
HO
ammonium
+
4
NH
110
111
The Acids of Chlorine and Their Anions
If the number of oxygens is one larger than the number
in the -ic acid, the prefix per- is placed before both the
acid and anion names:
HClO4 is perchloric acid and ClO4– is perchlorate ion
If the number of oxygens is one smaller than the
number in the -ic acid, the suffixes -ic and -ate are
replaced with -ous and -ite:
HClO2 is chlorous acid, and ClO2– is the chlorite ion
The Acids of Chlorine and Their Anions
•If the number of oxygens is two smaller than the
number in the -ic acid (one smaller than the number
in the -ous acid), the prefix hypo- is placed before
both the acid and anion names, and the -ous and ite suffixes are kept: HClO is hypochlorous acid and
ClO– is the hypochlorite ion
•The name of an acid with no oxygen is hydrofollowed by the name of the nonmetal, changed to
end in -ic: HCl is hydrochloric acid. The monatomic
anion from the acid is named by the rule for
monatomic anions, by which the elemental name is
changed to end in -ide: Cl– is the chloride ion
114
115
Acids
Oxy-acids contain
hydrogen, oxygen
and one other
element.
•
•
•
The other element
is usually a
nonmetal, but it
can be a metal.
Its first element is
hydrogen.
Its remaining
elements include
oxygen and form a
polyatomic ion.
116
Acids
Hydrogen in an
oxy-acid is not
expressed in the
acid name.
The word acid in
the name
indicates the
presence of
hydrogen.
117
Acids
indicates
hydrogen
sulfuric acid
contains
contains
contains
hydrogen
sulfur
oxygen
H 2SO 4
118
Acids
Anions ending in -ate always contain
more oxygen than ions ending in -ite.
phosphite
33
PO
phosphate
34
PO
119
Naming the Acid Based
on the Name of the Polyatomic Ion
Ending of Polyatomic Ion
ite
Ending of Acid
ous
less oxygen
ate
ic
more oxygen
120
Examples
sulfite
SO
2
3
sulfurous acid H 2SO3
121
Examples
sulfate
SO
2
4
sulfuric acid H 2SO 4
122
Examples
nitrite
NO

2
nitrous acid HNO2
123
Examples

3
nitrate
NO
nitric acid
HNO3
124
125
126
Chapter 6 – Nomenclature of
Inorganic Compounds
6.1 Common and Systematic Names
6.2 Elements and Ions – Naming elements and ions.
6.3 Writing Formulas from Names of Compounds –
Determine formula and name compound.
6.4 Binary Compounds – Naming and formulas for binary
compounds.
6.5 Naming Compounds Containing Polyatomic Ions
6.6 Acids – Binary and oxy-acids.
127