Page 101 - Theory and Problems of BEGINNING CHEMISTRY

90 INORGANIC NOMENCLATURE [CHAP. 6

Classical Nomenclature Systems
An older system for naming cations of elements having more than one possible cation uses the ending -ic
for the ion with the higher charge and the ending -ous for the ion with the lower charge. In this system, the Latin
names for some of the elements are used instead of the English names. Thus, this system is harder in two ways
than the Stock system, described above. You must know whether a particular ion has a related ion of higher or
lower charge, and you must know the Latin root. You should study this subsection if your text or your instructor
uses this system; otherwise you may omit it. The names for common ions in this system are given in Table 6-4.
Note that transition metals except the coinage metals do not have ions with charges of 1+. (This system was also
used in the past for nonmetal-nonmetal compounds also, and still exists in the designation of nitrogen oxides.
N 2 O is called nitrous oxide, and NO is called nitric oxide.)

Table 6-4 Names of Cations in Classical System

Transition Metals
Vanadous V 2+ Vanadic V 3+
Chromous Cr 2+ Chromic Cr 3+
Manganous Mn 2+ Manganic Mn 3+
Ferrous Fe 2+ Ferric Fe 3+
Cobaltous Co 2+ Cobaltic Co 3+
Nickelous Ni 2+ Nickelic Ni 3+
Cuprous Cu + Cupric Cu 2+
Argentous Ag + Argentic Ag 2+ (rare)
Aurous Au + Auric Au 3+
Mercurous Hg 2 2+ Mercuric Hg 2+
Palladous Pd 2+ Palladic Pd 4+
Platinous Pt 2+ Platinic Pt 4+
Main Group Metals
Stannous Sn 2+ Stannic Sn 4+
Plumbous Pb 2+ Plumbic Pb 4+
Inner Transition Element
Cerous Ce 3+ Ceric Ce 4+

Naming Anions
Common anions may be grouped as follows: monatomic anions, oxyanions, and special anions. There are
special endings for the first two groups; the third group is small enough to be memorized.

Monatomic Anions
If the anion is monatomic (has only one atom), the name of the element is amended by changing the
ending to -ide. Note that this ending is also used for binary nonmetal-nonmetal compounds. All monatomic
anions have names ending in -ide, but there are a few anions that consist of more than one atom which also end
−
−
−
−
in -ide—the most important of these are OH and CN .OH is called the hydroxide ion, and CN is called the
cyanide ion.
The charge on every monatomic anion is equal to the group number minus 8 (or 18 if the modern periodic
table group numbering system is used).