At what critical temperature does oxygen transform into a liquid under sufficient pressure?

• A. -150C
• B. -118C
• C. -100C
• D. -200C

Answer: (B)

Oxygen transitions from a gaseous state to a liquid state under specific temperature and pressure conditions. The critical temperature of oxygen is approximately -118°C. At this temperature, if enough pressure is applied, oxygen can be liquefied.

This transition occurs because, at temperatures above the critical temperature, the gaseous oxygen cannot be liquefied, regardless of the pressure applied. Conversely, temperatures below this critical point allow for the formation of liquid oxygen when adequate pressure is exerted. Understanding the significance of the critical temperature is essential for the safe handling and administration of oxygen, especially in medical and industrial applications, where oxygen is stored and used in liquid form under high pressure.