Nomenclature of
Inorganic Compounds
Chapter 6
Hein and Arena
Version 2.0
12th Edition
Eugene Passer
Chemistry Department
Bronx Community
1 College
© John Wiley and Sons, Inc
Chapter Outline
6.1 Common and Systematic
Names
6.2 Elements and Ions
6.4 Naming Binary Compounds
6.5 Naming Compounds
Containing Polyatomic Ions
6.3 Writing Formulas from
6.6 Acids
Names of Ionic Compounds
2
6.1
Common and
Systematic Names
3
Chemical nomenclature is the system of
names that chemists use to identify
compounds. Two classes of names exist:
common names and systematic names.
4
• 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).
5
6
6.2
Elements and Ions
7
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
8
These 7 elements are found
in nature as diatomic molecules.
Hydrogen
Nitrogen
Oxygen
Fluorine
Chlorine
Bromine
Iodine
H2
N2
O2
F2
Cl2
Br2
I2
9
Two elements are commonly polyatomic.
Sulfur
Phosphorous
S8
P4
10
Ions
11
charged
particle
known
as an ion
IfAone
or more
electrons
are removed
from
beatom
produced
or A
acan
neutral
a positivebyionadding
is formed.
removing
ora cation.
more electrons
positive
ion isone
called
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
14
Cations are named the same
as their parent atoms.
15
Atom
Cation
Name of
Cation
sodium (Na)
+
Na
sodium ion
16
Atom
Cation
Name of
Cation
calcium (Ca)
2+
Ca
calcium ion
17
Atom
Cation
Name of
Cation
lithium (Li)
+
Li
lithium ion
18
Atom
Cation
Name of
Cation
magnesium (Mg)
2+
Mg
magnesium ion
19
Atom
Cation
Name of
Cation
strontium (Sr)
2+
Sr
strontium ion
20
If
one or more
electrons
are added
A charged
particle
known
as an to
iona
neutral
atom
a negative by
ion isadding
formed.or
A
can be
produced
negative
is called
anion.electrons
removingionone
or an
more
from a neutral atom.
add e-
neutral atom
→
anion
21
Naming Anions
22
An anion consisting of one element has
the stem of the parent element and an –
ide ending
23
Atom
Anion
fluorine (F)
F
stem
Name of
Anion
fluoride ion
24
Atom
Anion
chlorine (Cl)
Cl
stem
Name of
Anion
chloride ion
25
Atom
Anion
bromine (Br)
Br
stem
Name of
Anion
bromide ion
26
Atom
Anion
nitrogen (N)
3N
stem
Name of
Anion
nitride ion
27
Atom
Anion
phosphorous (P)
3P
stem
Name of
Anion
phosphide ion
28
Atom
Anion
oxygen (O)
2O
stem
Name of
Anion
oxide ion
29
Ions are always formed by adding or
removing electrons from an atom.
30
Most often ions are formed when metals
combine with nonmetals.
31
The charge on an ion can be predicted
from its position in the periodic table.
32
elements
elements of
elements
of of of
elements
6A have
a
Group 2A have Group
a Group
5AGroup
have
a7A have
a
-2 charge
+2 charge
-3 charge
-1 charge
33
6.2
6.3
Writing Formulas From
Names of Ionic Compounds
34
A chemical compound must have a
net charge of zero.
35
If the compound contains ions,
then the charges on all of
the ions must add to zero.
36
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 37is 2
Write the formula of barium phosphide.
Step 1. Write down the formulas of the ions.
Ba2+ P3Step 2. Combine the smallest numbers of Ba2+
3- so that the sum of the charges
and
P
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 38is 6
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 39is 2
6.4
Naming Binary
Compounds
40
Binary compounds contain only
two different elements.
41
Binary ionic compounds consist of a
metal combined with a non-metal.
42
A. Binary Ionic Compounds Containing a
Metal Forming Only One Type of Cation
43
• 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.
44
Name of Metal
+ Stem of Nonmetal
plus -ide ending
45
46
Name the Compound CaF2
Step 1 From the formula it
is a two-element compound
and follows the rules for
binary compounds.
47
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.
48
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.
49
Name the Compound CaF2
Step 4 The name of the
compound is therefore
calcium fluoride.
50
Examples
51
Compound
NaCl
name of metal
Name
sodium
chloride
nonmetal stem
52
Compound
MgCl2
name of metal
Name
magnesium
chloride
nonmetal stem
53
Compound
K2O
name of metal
Name
potassium
oxide
nonmetal stem
54
Compound
Na3P
name of metal
Name
sodium
phosphide
nonmetal stem
55
B. Binary Ionic Compounds Containing a Metal
That Can Form Two or More Types of Cations
56
Name the Compound FeS
Step 1 This compound
follows the rules for a
binary compound.
57
Name the Compound FeS
Step 2 ItInissulfides,
a compound
the
of Fe, aon
charge
metal,
S is –2.
and S, a
nonmetal. the
Therefore
Fe charge
is a on
transition
Fe
must bemetal
+2, and
thatthe
has
more than
name
of theone
positive
type of
cation.
part of the compound
is iron(II).
58
Name the Compound FeS
Step 3 We have already
determined that the name
of the negative part of the
compound will be sulfide.
59
Name the Compound FeS
Step 4 The name of FeS
is iron(II) sulfide.
60
The Stock System
61
The metals in the center of the periodic
table (including the transition metals)
often form more than one type of
cation.
62
6.2
Each ion of iron forms a different
compound with the same anion.
Fe2+
FeS
Fe3+
Fe2S3
63
6.2
In IUPAC
the Stockdevised
Systemthe
the Stock
charge System
on the cation
of
is designated
nomenclature
by atoRoman
name numeral
compounds
placed
of in
parentheses
metals that
immediately
have more following
than one type
the name
of
of the
cation.
metal.
Cation
Charge
+1
+2
+3
+4
+5
Roman
Numeral
(I)
(II)
(III)
(IV)
(V)
The nonmetal name ends in -ide.
64
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
Hg 2+
2
mercury(I)
Hg2+
mercury(II)
Tin
Sn2+
Tin(II)
Sn4+
Tin (IV)
65
Examples
66
iron(II) chloride
FeCl2
+2
iron(II)
-1
chloride
compound
ion
ioncharge
name
name
iron(III) chloride
FeCl3
+3
iron(III)
-1
chloride
67
tin(II) bromide
SnBr2
+2
tin(II)
-1
bromide
compound
ion
ioncharge
name
name
tin(IV) bromide
SnBr4
+4
tin(IV)
-1
bromide
68
The Classical System
69
In the Classical System the name of the metal
(usually the Latin name) is modified with the
suffixes -ous and ic.
70
Metal name ends in
-ous lower charge
-ic higher charge
Nonmetal name ends in
-ide
71
Examples
72
ferrous chloride
FeCl2
+2
ferrous
-1
chloride
ion
compound
ioncharge
name name
ferric chloride
FeCl3
+3
ferric
-1
chloride
73
stannous bromide
SnBr2
+2
stannous
-1
bromide
compound
ion
ioncharge
name
name
stannic bromide
SnBr4
+4
stannic
-1
bromide
74
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
Hg2+
2
mercurous
Hg2+
mercuric
Tin
Sn2+
stannous
Sn4+
stannic
75
Binary Compounds
Containing Two Nonmetals
76
Compounds between nonmetals are
molecular, not ionic.
77
In a compound formed between two
nonmetals, the element that occurs first
in this series is named first.
•
•
•
•
•
•
Si
B
P
H
C
S
•
•
•
•
•
•
I
Br
N
Cl
O
F
78
Prefixes
79
A Greek prefix is placed before the name
of each element to indicate the number
of atoms of the element that are present.
80
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
81
Examples
82
dinitrogen trioxide
N2 O 3
indicates two
nitrogen atoms
indicates three
oxygen atoms
83
phosphorous pentachloride
PCl5
indicates one
phosphorous atom
indicates five
chlorine atoms
84
dichlorine heptaoxide
Cl2O7
indicates two
chlorine atoms
indicates seven
oxygen atoms
85
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 binary compounds of 2
nonmetals apply.
• Phosphorous is named first. Therefore the
compound is a chloride.
86
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.
87
Examples
88
Cl2O3
dichlorine trioxide
89
N2O3
dinitrogen trioxide
90
CCl4
carbon tetrachloride
91
CO
carbon monoxide
92
Name CO2
carbon dioxide
93
Name PI3
phosphorous triiodide
94
D. Acids Derived
from Binary Compounds
95
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 acid names are in addition to their
–ide names.
• Hydrogen is typically the first element
of a binary acid formula.
96
Acid Formation
binary hydrogen
compound (not
an acid).
water
acid
97
Pure compound
HCl
-ide
Dissolved in water
HCl
acid
98
• 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.
99
Examples
100
Pure Compound
HCl
hydrogen chloride
101
Dissolved in Water
HCl
hydrochloric acid
102
Pure Compound
HI
hydrogen iodide
103
Dissolved in Water
HI
hydroiodic acid
104
Pure Compound
H2 S
hydrogen sulfide
105
Dissolved in Water
H2 S
hydrosulfuric acid
106
Pure Compound
H2Se
hydrogen selenide
107
Dissolved in Water
H2Se
hydroselenic acid
108
109
6.5
Naming Compounds
Containing Polyatomic Ions
110
A polyatomic ion is an ion that
contains two or more elements.
NO
3
111
• 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
112
• When naming a compound containing
a polyatomic ion, name the cation first
and then name the anion.
Na 2CO3
sodium carbonate
113
This is the way the
formula is written.
KMnO 4
K
+
MnO
4
The ions are what is
actually present.
114
This is the way the
formula is written.
Na 2CO3
2Na
+
CO
23
The ions are what is
actually present.
115
Prefixes and Suffixes
Elements that Form More than One
Polyatomic Ion with Oxygen
116
Anions ending in -ate always contain
more oxygen than ions ending in -ite.
nitrite
2
NO
nitrate
3
NO
117
Anions ending in -ate always contain
more oxygen than ions ending in -ite.
phosphite
33
PO
phosphate
34
PO
118
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.
119
per- denotes anions with more oxygen
than the -ate form.
chlorate
3
ClO
perchlorate
4
ClO
120
hypo- denotes anions with less oxygen
than the -ite form.
hypochlorite
-
ClO
chlorite
2
ClO
122
124
Four polyatomic ions do not use
the –ate/ite system.
hydroxide
-
cyanide
-
hydrogen sulfide
-
peroxide
22
OH
HS
CN
O
125
There are three common positively
charged polyatomic ions.
mercury(I)
2+
2
Hg
hydronium
+
3
HO
ammonium
+
4
NH
126
127
128
6.6
Acids
129
Oxy-acids contain hydrogen, oxygen
and one other element.
130
Hydrogen in an
oxy-acid is not
expressed in the
acid name.
The word acid in
the name indicates
the presence of
hydrogen.
131
indicates
hydrogen
sulfuric acid
contains
contains
contains
hydrogen
sulfur
oxygen
H 2SO 4
132
Anions ending in -ate always contain
more oxygen than ions ending in -ite.
phosphite
33
PO
phosphate
34
PO
133
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
134
Examples
135
sulfite
SO
2
3
sulfurous acid H 2SO3
136
sulfate
SO
2
4
sulfuric acid H 2SO 4
137
nitrite
NO

2
nitrous acid HNO2
138

3
nitrate
NO
nitric acid
HNO3
139
140
141
6.5
142