Explain how, nitrogen, oxygen and argon gases are separated form air.

Air comprises of nitrogen, oxygen, carbon dioxide and argon as major components. Since air is the cheapest source of these gases, thus these are extracted from air at large scale. After liquefaction of air by repeated compression and cooling; nitrogen, oxygen, carbon dioxide and argon are extracted using fractional distillation. Liquid nitrogen has boiling point equal to - 196⁰C and thus turns into gas first and separated from air. The boiling point of argon is - 186⁰C, therefore it is extracted after argon. The boiling point of oxygen is - 183⁰C, thus it is collected after the extraction of argon. Carbon dioxide turns into solid at a temperature of - 97⁰C, therefore, it is removed while air is put under liquefaction.


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