The naming of salts has been discussed previously.AMPHOTERIC SUBSTANCES
Some substances, such as the HCO 3 − ion, the HSO 4 − ion, the H 2 O molecule, and
the NH 3 molecule, can act as either proton donors (acids) or proton receivers
(bases), depending upon which other substances they come into contact with.
These substances are said to be amphoteric. Amphoteric substances donate
protons in the presence of strong bases and accept protons in the presence of
strong acids.
Examples are the reactions of the bisulfate ion, HSO 4 −:
With a strong acid, HSO 4 − accepts a proton:HSO 4 −(aq) + H+(aq) → H 2 SO 4 (aq)With a strong base, HSO 4 − donates a proton:HSO 4 −(aq) + OH−(aq) → H 2 O(ℓ) + SO 4 2−(aq)ACID RAIN—AN ENVIRONMENTAL CONCERN
Acid rain is currently a subject of great concern in many countries around the
world because of the widespread environmental damage it reportedly causes. It
forms when the oxides of sulfur and nitrogen combine with atmospheric moisture
to yield sulfuric and nitric acids—both known to be highly corrosive, especially
to metals. Once formed in the atmosphere, these acids can be carried long
distances from their source before being deposited by rain. The pollution may
also take the form of snow or fog or be precipitated in dry form. This dry form is
just as damaging to the environment as the liquid form.
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Acid rain is the result of the formation of sulfuric acid from sulfur oxides reacting with water.
Nitrogen oxides are also involved.The problem of acid rain can be traced back to the beginning of the industrial
revolution, and it has been growing ever since. The term “acid rain” has been in
use for more than a century and is derived from atmospheric studies made in the
region of Manchester, England.
In 1988, as part of the Long-Range Transboundary Air Pollution Agreement
sponsored by the United Nations and the United States, along with 24 other