Naming Simple Compounds
• I. Binary compounds: are those composed of only two elements.
• 1) Binary compounds of metals and nonmetals.
• If one element is metal and the other a nonmetal; the binary compound is
made up of ions. The simplest are monatomic ions. A monatomic ion is an
ion formed from a single atom.
• Table 4.1 Common Monatomic Ions of Man-Group Elements
IA
IIA
IIIA
IVA
VA
VIA
VIIA
Period 2 Li+
Be2+
B
C
N3-
O2-
F-
Period 3 Na+
Mg2+
Al3+
Si
P
S2-
Cl-
Period 4 K+
Ca2+
Ga3+
Ge
As
Se2-
Br-
Period 5 Rb+
Sr2+
In3+
Sn2+, Sn4+
Sb
Te2-
I-
Period 6 Cs+
Ba2+
Tl+, Tl3+
Pb2+, Pb2+
Bi3+
Period 1 H+,
H(hydride)
Binary compounds
When use old group number- Roman numeral plus letter A or B, the
charge on a cation for main-group element, in most cases, equals the
group number ( the Roman numeral).
For example, aluminum, which is in group IIIA, has an ion with charge
3+. Some exceptions are noted for elements of high atomic number
such as lead, in group IVA, whose common ion is Pb 2+. The charge
on an anion euals the group number minus 8. Oxygen, in group VIA,
has an anion charge of 2- (6-8).
Most transition elements have cations of several different charges (see
Table 4.2). For example, iron has the cations Fe2+ and Fe3+.
Table 4.2 Some Common Ions of the Transition Elements: only ions
Ions
Cr3+
Mn2+
Systemic Name
Chromium (III)
Manganese (II)
Common Name
Chromic
Manganous
Fe2+
Fe3+
Co2+
Iron (II)
Iron(III)
Cobalt(II)
ferrous
ferric
cobaltous
Ni2+
Cu2+
Ag+
Zn2+
Nickel(II)
Copper(II)
Silver
Zinc
Cupric
name a binary compound of a metal and nonmetal
•
- Write the unmodified name of the metal.
• - Then write the name of the nonmetal, modified to end in ide.
name unchange
Sodium chloride
NaCl
ide ending
- The overall zero charge is provided for by adjusting the ratio of
cations and anions.
tin(II) fluoride SnF2
calcium chloride
CaCl2
silver sulfide
Ag2S
chromium(III) chloride CrCl3
The main group metals and nonmetals form ions related to their group number.
Elements that can form more than one cation
• If an element can form more than one cation, the positive charge of
the ion is denoted by a Roman numeral in parentheses following the
element name. Most of transition metals have cations of several
different charges.
• Fe2+ iron(II) ion
FeS
iron(II) sulfide
• Fe3+ iron(III) ion
Fe2S3 iron(III)sulfide
• In an earlier system of nomenclature, such ions are named by adding
suffixes ous and ic to a stem name of the element to indicate the ions
of lower and higher charge, respectively. The ending ous is used for
lower oxidation state of the metal and ic ending for the higher
oxidation state. You need to know this system of nomenclature
since it is still commonly used.
• Cu+ cuprous ion
Cu2O cuprous oxide.
• Cu2+ cupric ion
CuO cupric oxide.
Binary Compounds of two Nonmetals or metalloids
Write the element with positive charge first
• - Then, write the name of the following element, modified to end in ide
• E.g. HCl hydrogen chloride
• When two elements form more than one compound, we indicate
relative number of atoms through the appropriate prefixes:
•
-
•
•
•
•
•
•
•
Table 1 Greek Prefixes for Naming Compounds____________
Number
Prefixes
Number
Prefixes
1
mono
6
hexa
2
di
7
hepta
3
tri
8
octa
4
tetra
9
nona
5
penta
10
deca___
• Example:
• CO
carbon monoxide
• BCl3
boron trichloride
• N2O
dinitrogen monoxide
• PCl5
phosphorus pentachloride
CO2
carbon dioxide
CCl4
carbon tetrachloride
B2Br4
diboron tetrabromide
SF6
sulfur hexaflouride
Polyatomic ions
• A polyatomic ions is an ion consisting of two or more atoms chemically
bonded together and carrying a net electric charge.
• The most familiar polyatomic cations are the following:
• NH4+ ammonium ion
Hg22+ mercury (I) or mercurous ion
• The name mercury(I) is given to Hg22+ because it can be considered to
consist of two Hg+ ions. Mercury also occurs as the monoatomic Hg2+
ion, which is known as the mercury(II) or mercuric ion.
• Very few polyatomic anions carry the ide ending in their names.
• OH¯ hydroxide ion CN¯ cyanide ion
O22peroxide ion
oxoanions.
An element common to many polyatomic ions is oxygen,
usually in combination with another nonmetal. Such anions
are called oxoanions. Certain nonmetals such as Cl, N, P
and S from a series of oxoanions containing different
numbers of oxygen atoms. When an element has two
oxoanions, the name of the one with higher oxidation state
(more oxygens) ends in –ate; the name of the one with
lower oxidation state (less oxygen) ends in –ite.
•
NO2¯ nitrite ion
SO32¯ sulfite ion
•
NO3¯ nitrate ion
SO42¯ sulfate ion
• When the series of oxoanions of a given element extends to three or
four, the prefix hypo indicates less oxygen and the prefix per indicates
more oxygen is used along with the suffixes ite and ate.
•
•
•
•
•
increasing oxidation state of nonmetal 
hypo_ite
_ite
_ate
increasing number of oxygen atoms 
ClO¯
ClO2¯
ClO3¯
hypochlorite
chlorite
chlorate
per _ate
ClO4¯
perchlorate ion
• d) Some series of oxoanions also contain varying numbers of H
atoms. These ions are named by prefixing the word hydrogen or
dihydrogen as appropriate, to the name of hydrogen-free anion.
•
IUPAC name
common name
• HCO3¯
hydrogen carbonate ion
bicarbonate ion
• HSO4¯
hydrogen sulfate ion
bisulfate ion
• HPO42¯
hydrogen phosphate ion
• H2PO4¯
dihydrogen phosphate ion
• e) All the common oxoanions of Cl, Br, and I carry a charge of
1-.
• f) The prefix thio signifies that a sulfur atom has been substituted
for an oxygen atom.
•
S2O32thiosulfate ion
Acids
• An acid is a substance that produces one or more hydrogen ions
(H+) when dissolved in water.
• a) Binary Acid
• Binary acids are certain compounds of H with other nonmetal
atoms yield acidic solution when dissolved in water.
• In naming acids we use the prefix hydro followed by the name
of the other nonmetal modified with an ic ending.
• _binary compound
acid solution___________
• HF(g) hydrogen fluoride
HF(aq) hydrofluoric acid
• H2S(g) hydrogen sulfide
H2S(aq) hydrosulfuric acid
Oxoacids
• An oxoacid is an acid containing hydrogen, oxygen and
another element. In water the oxoacid molecule yields
one or more hydrogen ions and an oxoanion.
• The name of oxoacid and corresponding oxoanion are
related. When the name of anion ends in -ite, the name
of acid ends in -ous.
• Oxoanions whose names end in ate have associated
acids whose names end in -ic. Prefixes in the name of
the oxoanion are retained in the name of the acid.
Some Oxoacids and Their Corresponding Oxoanions
Oxoacids
Oxoanions
H2CO3
HNO2
HNO3
H3PO4
carbonic acid
nitrous acid
nitric acid
phosphoric acid
CO32NO2¯
NO3¯
PO43-
carbonate ion
nitrite ion
nitrate ion
Phosphate ion
H2SO3
H2SO4
HClO
sulfurous
sulfuric acid
hypochlorous acid
SO32SO42ClO¯
sulfite
sulfate
hypochlorite ion
HClO2
chlorous acid
ClO2¯
chlorite ion
HClO3
chloric acid
ClO3¯
chlorate ion
HClO4
perchloric acid
ClO4¯
Perchlorate ion