Use of gases(Oxygen,Nitrogen, Hydrogen, Carbon Dioxide,etc.)

Oxygen
- one of the life-sustaining elements on Earth and is needed by all animals
- in blast furnaces to make steel
- an important component in the production of many synthetic chemicals, including ammonia, alcohols, and various plastics.
- oxygen and acetylene are combusted together to provide the very high temperatures needed for welding and metal cutting
- utilized in medicine in the treatment of respiratory diseases and is mixed with other gases for respiration in submarines, high-flying aircraft, and spacecraft
- liquid oxygen is used as an oxidizer in the fuel systems of large rockets
Nitrogen
- in a wide variety of important manufactures, including ammonia, nitric acid, TNT, and fertilizers
- nitrogen fixation, achieved naturally by soil microbes and industrially by the Haber-Bosch process, converts it to water-soluble compounds (including ammonia and nitrates). Industrially, ammonia is the starting material for most other nitrogen compounds (especially nitrates and nitrites), whose main uses are in agricultural fertilizers and explosives.
- to some extent for filling light bulbs, in thermometers, and generally anywhere a relatively inert atmosphere is needed, as in the production of electronic parts such as transistors, diodes, and integrated circuits, and in food storage packaging to prevent spoilage.
- in the manufacture of stainless steel and as a coolant for the immersion freezing of food products, for the transportation of foods, for the preservation of bodies and reproductive cells (sperm and eggs), and for the storage of biological samples.
Hydrogen
- in the production of synthetic ammonia and methanol. The largest single use of hydrogen is in the synthesis of ammonia. Ammonia plants are often built adjacent to petroleum refineries or coking plants to utilize by-product hydrogen that might otherwise be wasted. Methanol is produced commercially by reaction of hydrogen with carbon monoxide. Reaction of hydrogen with chlorine is a major source of hydrochloric acid.
- in petroleum refining. An important use for hydrogen is in petroleum-refining operations, such as hydrocracking and hydrogen treatment for removal of sulfur.
- in the Haber process for the fixation of atmospheric nitrogen
- in the hydrogenation of organic materials. Large quantities of hydrogen are consumed in the catalytic hydrogenation of unsaturated liquid vegetable oils to make solid fats. Hydrogenation is used in the manufacture of organic chemicals, such as alcohols from esters and glycerides, amines from nitriles, and cycloparaffins from aromatic hydrocarbons.
- in oxyhydrogen torches
- in rocket fuels
- as a shielding gas in welding methods such as atomic hydrogen welding
- as the rotor coolant in electrical generators at power stations, because it has the highest thermal conductivity of any gas.
- liquid hydrogen is used in cryogenic research, including superconductivity studies
- formerly used for filling balloons, airships, and other lighter-than-air craft, a dangerous practice because of hydrogen's explosive flammability. However, hydrogen is still regularly used for the inflation of weather balloons.
Carbon dioxide
- as a chemical is in the production of carbonated beverages
- formed by the action of yeast or baking powder, carbon dioxide causes the rising of bread dough
- in water softening
- in the manufacture of aspirin and lead paint pigments
- in the Solvay process for the preparation of sodium carbonate
- in some fire extinguishers carbon dioxide is expelled through a nozzle and settles on the flame, smothering it
- as a pressurizing medium and propellant, e.g., in aerosol cans of food, in fire extinguishers, in target pistols, and for inflating life rafts. Because it is relatively inert, it is used to provide a nonreactive atmosphere, e.g., for packaging foods, such as coffee, that can be spoiled by oxidation during storage
- solid carbon dioxide, known as dry ice, is used as a refrigerating agent