Page 78 - Encyclopedia of Chemical Compounds 3 Vols

H C C H

OTHER NAMES:
Ethyne; ethine
FORMULA:
CH=CH
Acetylene
ELEMENTS:
Carbon, hydrogen
COMPOUND TYPE:

hydrocarbon; OVERVIEW
organic)
Acetylene (uh-SET-ill-ene) is the simplest hydrocarbon,
Alkyne (unsaturated KE
STATE: Y consisting of two carbon atoms joined to each other by a
triple bond with their associated hydrogen atoms. It occurs
as a colorless gas with a sweet odor when pure, but an
Gas F
MOLECULAR WEIGHT: A
unpleasant odor due to the presence of phosphine (PH 3 )
26.04 g/mol
and/or arsine (AsH 3 ), with which it is often contaminated.
C
MELTING POINT: T Acetylene is a highly flammable gas that is also somewhat

80.8 C( 113 F)
explosive. This property accounts for one of its most impor-
S
BOILING POINT: tant uses, in torches that burn at very high temperatures.

84 C( 120 F) Acetylene was discovered by the British chemist
SOLUBILITY: Edmund Davy (1785–1857) in 1836. Davy obtained the gas
Slightly soluble in accidentally when he combined water with potassium carbide
water and alcohol; (KCH 2 ) while attempting to make potassium metal. He noted
soluble in acetone that the gas burned with a bright flame and thought it
and benzene might be used as a source of illumination. That application
was impractical, however, because of the high cost of potas-
sium carbide. When the German chemist Frederich Wo ¨hler
(1800–1882) discovered the far less expensive calcium carbide

CHEMICAL COMPOUNDS 27