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

Key Points

• Carbon dioxide (CO₂) can transition to a supercritical fluid state when cooled and compressed beyond its critical temperature and pressure.
• A supercritical fluid is a state of matter where distinct liquid and gas phases do not exist.
• Supercritical CO2 is commonly used in various industrial applications, including supercritical fluid extraction and as a solvent in chemical processes.
• The critical temperature and pressure for CO₂ are 31.1°C and 73.8 atm, respectively.

Additional Information

• Supercritical fluids have properties of both liquids and gases, making them versatile in various scientific and industrial processes.
• The use of supercritical CO₂ is favored for its non-toxic, non-flammable nature and its ability to act as a solvent without the need for hazardous chemicals.
• Other gases can also become supercritical fluids under the right conditions, but CO₂ is one of the most commonly utilized due to its relatively low critical temperature and pressure.
• Understanding the behavior of supercritical fluids is important in fields such as materials science, chemistry, and engineering.