Question

what are the ways a gas can be liquefied ?​

Answer 1

Answer:

Gases can be liquefied by one of three general methods: (1) by compressing the gas at temperatures less than its critical temperature; (2) by making the gas do some kind of work against an external force, causing the gas to lose energy and change to the liquid state; and (3) by making gas do work against its own internal forces, also causing it to lose energy and liquefy.

Answer 2

Answer:

By adding pressure and reducing the temperature, gases can be liquified

Explanation:

When pressure on a gas is increased, its molecules closer together, and its temperature is reduced, which removes enough energy to make it change from the gaseous to the liquid state.