Page 194 - Encyclopedia of Chemical Compounds 3 Vols

Ca

O C O

O

OTHER NAMES:
Limestone; chalk;
aragonite; calcite

FORMULA:
CaCO 3
ELEMENTS:
Calcium, carbon, Calcium Carbonate
oxygen
COMPOUND TYPE:
Inorganic salt
STATE: OVERVIEW
Solid KE
Calcium carbonate (KAL-see-um CAR-bun-ate) is one of
MOLECULAR WEIGHT: Y the most common compounds on Earth, making up about
7 percent of Earth’s crust. It occurs in a number of minerals
100.09 g/mol F
MELTING POINT: A and other natural materials, including aragonite, calcite,
chalk, limestone, marble, marl, oyster shells, pearls, and tra-

(2430 F); aragonite: vertine. Stalactites and stalagmites found in caves are made
Calcite: 1330 C C
decomposes at about T primarily of calcium carbonate. As indicated by the melting

825 C (1520 F) S points of aragonite and calcite, the compound’s physical
BOILING POINT: properties may differ somewhat depending on its crystal
Not applicable form. It typically occurs as an odorless, tasteless white pow-
der or colorless crystals.
SOLUBILITY:
Very slightly soluble
in water; soluble in HOW IT IS MADE
dilute acids; insoluble
in organic solvents Calcium carbonate is so abundant in nature that demand
for the compound can be met by mining natural sources,
such as chalk, limestone, and marble quarries. The com-
pound can also be produced in the laboratory by reacting

CHEMICAL COMPOUNDS 143