Acids are familiar to us because of their power as corrosive agents
and solvents, bringing into solution compounds that are insoluble
in water alone
Strong acids will attack many metals, converting them to soluble
ions and liberating bubbles of hydrogen gas in the process.
Acids also will dissolve carbonates such as limestone, and certain
other minerals and inorganic compounds. The weaker acids that are
safe to taste, such as citric acid in lemons and acetic acid in
vinegar, have a characteristic mouth puckering sharp taste that
we immediately recognize and designate as "acid".
Bases also are useful for dissolving water-insoluble substances,
especially oils, greases, and other organic compounds. Sodium hydroxide,
for example, will attack the oils of the skin and turn them into
soap, which is why solutions of household lye feel slippery to the
We have seen previously that there are many substances, amphoteric
oxides among them, that are insoluble in plain water but are dissolved
either by an acid or a base, or both.