Binary acids are named by writing hydro followed by the root of the name of the
halogen, then -ic, and finally acid (Table 5.2):
hydro(root)ic acid
The only exception to remember is that the “o” in hydro is left off for HI(aq), so its
name is hydriodic acid (an acid used to make pharmaceuticals).
Most chemists refer to pure HCl gas as hydrogen chloride, but when HCl gas is
dissolved in water, HCl(aq), the solution is called hydrochloric acid. We will follow the
same rule in this text, calling HCl or HCl(g) hydrogen chloride and calling HCl(aq)
hydrochloric acid. The same pattern holds for the other binary acids as well.
You will be expected to be able to write formulas and names for the binary acids
found on Table 5.2. Remember that it is a good habit to write (aq) after the formula.