Question

Suggest a method to liquefy atmospheric gases.

Answer 1

Hint: We know that the gases present in the earth’s atmosphere are referred to as atmospheric gases. A major portion of atmospheric gas comprises nitrogen and oxygen. Other gases include $C{O_2}$, water vapour, ozone, etc.

Complete answer:
The liquefaction of atmospheric gases means converting them into the liquid. But the atmospheric gases such as nitrogen, oxygen, etc. exist in liquid form only at significantly low temperature for example at \[ - 150^\circ C{\rm{ }} or - 200^\circ C\]. To attain this much low temperature only by cooling is a much difficult task to perform. So, it is quite difficult to liquefy the atmospheric gases only by cooling them to a lower temperature.

So, in order to liquefy the atmospheric gases, it is necessary to compress them and bring their molecules much closer to each other. This can be done by applying a very high pressure to them so that they can be compressed easily. Along with this, there is also a need to lower down the temperature to a great extent. When the atmospheric gases are exposed to a very high pressure the particles of the gas get closely packed with each other occupying a very small volume. But during this process of compressing them a large amount of heat is produced. So, in order to reduce the effect of heat produced it becomes necessary to lower the temperature of the gases.

Hence, the atmospheric gases can be liquefied by exposing them to a very high pressure and low temperature.

Note:Thus, due to the existence of atmospheric gases as liquid at extremely low temperature, it becomes practically impossible to liquefy them merely by cooling. So in order to make the liquefaction of the atmospheric gases practically easy and possible, they are made exposed to the extremely high pressure and a very low temperature. The need for lowering the temperature arises in order to reduce the effect of the heat produced during the process of compressing the gases.