Which set of conditions represents the easiest way to liquify a gas ?
A
Low temperature and high pressure
B
High temperature and low pressure
C
Low temperature and low pressure
D
High temperature and high pressure
Correct Answer: Low temperature and high pressure
Low temperature and high pressure set of conditions represents the easiest way to liquefy a gas. Liquefaction of gases is physical conversion of a gas into a liquid state (condensation). The processes are used for scientific, industrial and commercial purposes. Many gases can be put into a liquid state at normal atmospheric pressure by simple cooling; a few, such as carbon dioxide, require pressurization as well. Liquefaction is used for analyzing the fundamental properties of gas molecules (intermolecular forces), for storage of gases. The liquefaction of gases is a complicated process that uses various compressions and expansions to achieve high pressures and very low temperatures, using, for example, turbo-expanders.