At what temperature does liquid oxygen boil?

• A. negative 297 degrees
• B. positive 297 degrees
• C. negative 150 degrees
• D. zero degrees

Answer: (A)

Liquid oxygen has an extremely low boiling point at standard atmospheric pressure. Its boiling point is about -183°C, which is -297°F. In aviation maintenance contexts, temperatures are often given in Fahrenheit, so -297°F is the temperature at which liquid oxygen boils. That’s why the option listing negative 297 degrees (in the Fahrenheit scale) is correct. At any temperature warmer than this, LOX will vaporize; at colder temperatures it remains liquid. The other choices are not the LOX boiling point.