a. The names for the binary acids are formed by using the prefix hydro-, the root
name for the anion, and the suffix -ic, followed by the word "acjd." For example, HCl is
called hydrochloric acid.
b. An exception to this rule is hydrocyanic acid which has the formula HCN.
Although this is a ternary acid, the cyanide radical (CN -1) is usually treated like a halide
ion when naming its compounds.
c. The binary acids are really covalent compounds which act as acids only when
they are in solution, especially in water. When you know that one of the binary acids is
by itself, you can properly name it in a similar manner to the salts; thus, HCl as a pure
gas would be called hydrogen chloride.
(a) HBr is called _________________________________________ .
HI is called ___________________________________________ .
H2S is called _________________________________________ .
(d) HF gas is called _______________________________________ .
(a) Hydrobromic acid.
(b) Hydriodic acid.
(d) Hydrogen fluoride.
1-15. NAMING TERNARY ACIDS
a. The ternary acids generally are made of hydrogen ion combined with one of
the radicals that contain oxygen. For this reason, they are often referred to as
b. When naming the ternary acids, the suffixes on the names of the radicals are
changed and followed by the word "acid" to show the presence of the hydrogen.
Radicals ending in -ate change their suffix to -ic; radicals ending in -ite change their
suffix to -ous. The prefixes, if there are any, are not changed. Occasionally, an extra
syllable is added in the middle of the name for pronunciation purposes--these do not
follow any pattern and must be learned. Here are some examples of naming ternary
acids from the radicals: