Give three examples of practical application which is based on high compressibility of gases.

Hint: The compressibility of gas is defined as the change in volume of the gas per unit change in the pressure applied on the gas. Another factor that plays an important role in compression of gas is critical temperature.

Complete step by step answer: The critical temperature, pressure and volume are called the critical constants.
 Critical temperature of a gas is the highest temperature at which the liquefaction of the gas first occurs. Whereas, volume of one mole of gas at critical temperature is called critical volume $({V_C})$ and pressure at this temperature is called critical pressure $({P_C})$.
The proper orientation of this critical constant's aids the compressibility of gas.
 Three example of practical application which is based on high compressibility of gases are:
(A) Compressed natural gas (CNG): CNG is used as fuel in vehicles. It is a cheap eco-friendly fuel. CNG is used in vehicles as fuel as it has very high compressibility. Therefore large volumes of CNG can be compressed and stored in the CNG cylinder for easy transportation.
(B) Liquefied petroleum gas (LPG): LPG cylinders are commonly found in every house. It is used as a cooking fuel. The gas is highly compressible and thus a large amount of gas is stored in a cylinder.
(C) Oxygen cylinders: Oxygen gas is a compulsion for respiration. Oxygen $({O_2})$ gas is stored in a cylinder which is commonly used in hospital, scuba diving etc.

Note: Different gases have different values of compressibility as their constituent atoms are different. Conditions like temperature, volume and pressure are the determining factors in the compression of gas.