Untitled - Kelly Walsh High School

26 CHEMISTRY FOR THE UTTERLY CONFUSED
ion, Fe 3 is the ferric ion, Cu is the cuprous ion, and Cu 2 is the cupric ion. The
ion with the greater charge always has the “-ic” suffix.
To avoid the necessity of memorizing a separate name for each ion, we can use
the Stock system. In the Stock system, the charge of the cation appears as a
Roman numeral immediately after the name of the element. Using the Stock
system, we write Fe 2 as the iron(II) ion, and Cu as the copper(I) ion. Other
than the necessity of indicating the charges, there are no differences between
the naming of transition metal compounds and other compounds of the metals.
So while KCl is potassium chloride, CuCl is copper(I) chloride.
Finally, we need to consider compounds containing the nonmetal hydrogen.
Remember that hydrogen is an exception. In simple binary compounds with
nonmetals, we treat hydrogen as a metal. As a “metal” in the first column, it
should have a 1 charge. Thus, H 2S is hydrogen sulfide.
Many hydrogen compounds are acids. Acids require a different system of
nomenclature than other compounds. There are two types of acids: binary acids
and ternary acids. All acids include the word acid in their name. Binary acids
contain only two elements: one of which is hydrogen and the other a nonmetal.
When naming binary acids, the prefix “hydro-” appears before the root name
of the nonmetal, and there will be an “-ic” suffix. As an acid, H 2S would be
hydrosulfuric acid. We used H 2S to illustrate the fact that there can be two possible
names, hydrogen sulfide or hydrosulfuric acid. If your instructor does not
specify which name to use, either is correct. Technically, the name hydrosulfuric
acid only applies to aqueous solutions of H 2S, H 2S(aq).
The ternary acids consist of hydrogen combined with a polyatomic ion. As with
binary acids, the word acid must appear in the name. The remainder of the
name of the acid will come from the name of the polyatomic ion. Ions ending in
“-ite” have these three letters changed to “-ous”, and ions ending in “-ate” have
these three letters changed to “-ic”. Thus, the nitrite ion, NO 2 , becomes nitrous
acid, HNO 2, and the nitrate ion, NO 3 , becomes nitric acid, HNO3. Some ions
require a little more work; for example, the sulfate ion, SO 4 2 , becomes sulfuric
acid, H 2SO 4.
In this chapter, you learned about the atom and the three basic subatomic particles:
protons, neutrons, and electrons. You also learned about the periodic
table and about the classification of the various elements on the periodic
table. Classifications include metal, metalloid, nonmetal, and classification
according to the family (group) and period. You also learned the difference
between ions and molecules, and how to name ionic compounds and molecules
systematically.