Argon (Ar)
Argon is a colourless and odourless inert gas made up of monatomic molecules. It does not exist in nature other than in air (0.93%). It cannot sustain life, but it is used in industrial applications due to its high level of chemical inertness and the relative ease with which it can be produced.
Argon is available as gas in cylinders and tube trailers as well as bulk liquid in Dewars, semitrailers and ISO’s.
Properties |
U.S. Units |
S.I. Units |
Chemical formula |
Ar |
Ar |
Molecular weight |
39.95 |
39.95 |
Density of the gas at 70°F (21.1°C) and 1atm. |
0.103 lb /ft3 |
1.654 kg/m3 |
Specific gravity of the gas at 70°F (21.1°C) and 1 atm |
1.38 |
1.38 |
Specific volume of the gas at 70°F (21.1°C) and 1 atm |
9.71 ft3/lb |
0.606 m3/kg |
Density of the liquid at boiling point and 1 atm |
87.02 lb/ft3 |
1394 kg/m3 |
Melting point at 1 atm. |
-308.6°F |
-189.2°C |
Critical temperature |
-188.1°F |
-122.3°C |
Critical pressure |
711.5 psia |
48.9 bar |
Critical density |
33.44 lb/ft3 |
537.7 kg/m3 |
Boiling point at 1 atm |
-302.6°F |
-185.9°C |
Solubility in water vol/vol at 32°F(0°C)& 1 atm. |
0.0537 |
0.0537 |
Industry |
Usage |
Laboratories |
Used for industrial and hospital analysis |
Metal fabrication |
It is a shield gas used in arc welding, root shielding and plasma cutting. |
Steel and metals |
Mainly used in the AOD process (decarburizing) stainless steel. |
Glass |
It is used for the filling of double glazing enclosures for high performance thermal isolation. |
Electronics and semiconductor |
Ultra-pure argon is used as carrier gas for reactive molecules, as an inert gas to protect semiconductors against impurities, |
Other applications |
It is used as inert atmosphere in incandescent light bulbs. Used for inflating vehicles airbags. |