Page 195 - Encyclopedia of Chemical Compounds 3 Vols

CALCIUM CARBONATE

Calcium carbonate. Red atoms
are oxygen; black atom is
carbon; white atom is calcium.
Gray stick is a double bond.
PUBLISHERS RESOURCE GRO U P

calcium chloride (CaCl 2 ) with sodium carbonate (Na 2 CO 3 ). The
calcium carbonate formed in this reaction precipitates out of
(separates from) the solution and can be recovered by filtration.

COMMON USES AND POTENTIAL HAZARDS
One well known use of calcium carbonate is as an antacid,
a substance that neutralizes excess stomach acid (hydrochlo-
ric acid; HCl) and relieves the symptoms of acid indigestion,
heartburn, upset stomach, and sour stomach. Large amounts
of the chemical are also used for a variety of industrial uses,
including:
• In agriculture, where it is used to maintain proper
acidity of soil and supply calcium needed by growing
plants;

144 CHEMICAL COMPOUNDS