The liquefaction of gases is the process of converting a gas into a liquid by cooling (lowering temperature) and/or compressing (increasing pressure) the gas.
- At lower temperatures, gas molecules lose kinetic energy and come closer together.
- At higher pressures, the gas molecules are forced into a smaller space, which encourages intermolecular attractions.
- When both effects combine, the gas molecules condense into the liquid state.
In simple words:
Liquefaction of gases = making a gas turn into liquid by cooling and applying pressure.
For example:
- Oxygen and nitrogen can be liquefied and stored in cylinders.
- Liquefied Petroleum Gas (LPG) is stored under pressure as a liquid.