Nitrogen (N), when cooled, condenses at -320.42°F
(-195.8°C or 77.36 K) and freezes at -345.9°F (-209.86°C or
63.17 K). Or, to reverse the order, solid nitrogen melts to form
liquid nitrogen at -345.9°F, which boils at -320.42°F Liquid
nitrogen is used in a wide range of cryogenic applications.
The Scottish physician Daniel Rutherford discovered nitrogen in 1772.
It is the fifth most abundant element in the universe and makes up
about 78% of the earth's atmosphere, which contains an estimated 4,000
trillion tons of the gas. Nitrogen is obtained from liquefied air
through a process known as fractional distillation.
The largest use of nitrogen is for the production of ammonia
(NH3). Large amounts of nitrogen are combined with hydrogen to produce ammonia in a method known as
the Haber process. Large amounts of ammonia are then used to create
fertilizers, explosives and, through a process known as the Ostwald process,
nitric acid (HNO3).
Nitrogen gas is largely inert and is used as a protective shield in the
semiconductor industry and during certain types of welding and soldering
operations. Oil companies use high-pressure nitrogen to help force crude
oil to the surface. Liquid nitrogen is an inexpensive cryogenic liquid used
for refrigeration, preservation of biological samples and for low temperature
scientific experimentation.
|
 |
| Atomic Number |
7 |
| Atomic Weight |
14.0067 |
| Melting Point |
63.15 K |
| Boiling Point |
77.36 K |
| Heat of Vaporization |
198.3 kj/kg K |
| Specific Heat |
2.04 kj/kg K |
| Viscosity |
157.9 kg/m-s X 106 |
| Thermal Conductivity |
139.6 mW/m-k |
| Dielectric Constant |
1.434 |
| Critical Temperature |
126.2K |
| Critical Pressure |
3.399 MPa |
| Temperature at Triple Point |
63.148 K |
| Pressure at Triple Point |
12.53 Mpa X 103 |
| Density |
.0012506 grams/cc |
| Phase at Room Temperature |
Gas |
|
