1-11. NAMING METALLIC CATIONS
Many metallic elements have only one possible valence. The names for the
cations formed by these metals are given the name of the element. For example, Na+1
is called sodium ion; Ca+2 is called calcium ion. Other metallic elements, however, may
have more than one valence. Since valence is a measure of combining power, these
elements may form more than one compound with the same anion. Therefore, we must
have some way to differentiate between the varying valences when we name them.
There are two common methods for doing this.
a. The first method uses a root word from the name of the element (or the Latin
name for the element) with a suffix to indicate the valence state. The suffix --ous
indicates the lower valence; the suffix --ic indicates the higher valence. For example,
Hg+1 is called mercurous ion, but Hg+2 is called mercuric ion.
Questions. (You may wish to refer to table 1-3.)
(a) Al+3 is called ______________________ ion.
(b) Fe+2 is called ferr-- ______________________ ion.
Fe+3 is called ferr-- ______________________ ion.
(d) K+1 is called ______________________ ion.
(e) Cu+1 is called cupr- ______________________ ion.
Cu+2 is called cupr- ______________________ ion.
(g) Ba+2 is called ______________________ ion.