Which of the following gases, when cooled and compressed, can change from a gas to a supercritical fluid state?

Correct option is C

The correct answer is (c) Carbon dioxide (CO2).
· Carbon dioxide can transition into a supercritical fluid state when cooled and compressed beyond its critical temperature and pressure.
· In this state, CO2 exhibits properties of both liquids and gases, making it useful in various industrial applications, such as decaffeination of coffee and extraction processes.
· The critical temperature for CO2 is 31.1°C, and the critical pressure is 73.8 atm.
Information Booster:
Oxygen (O2):
· Oxygen can be liquefied but is not commonly used as a supercritical fluid due to its high critical temperature and pressure.
Hydrogen (H2):
· Hydrogen can also exist as a supercritical fluid but requires extremely low temperatures and high pressures.
Steam:
· Steam is water in its gaseous form, and while it can exist as a supercritical fluid (supercritical water), it requires much higher pressures and temperatures than CO2.