N2O Cylinder Pressure 4400 kPa — FRCA Primary MCQ

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EasyPhysics & Clinical MeasurementN2O Cylinder Pressure 4400 kPaFRCA Primary

The pressure in a full nitrous oxide cylinder at 20°C is approximately:

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Correct answer: A — 4400 kPa

A full N2O cylinder at 20°C has a pressure of approximately 4400 kPa (44 bar / 640 psi). This is the saturated vapour pressure of N2O at 20°C. The pressure remains constant until all liquid has evaporated (approximately 75% of contents used) then falls linearly.

Reference: Al-Shaikh Stacey 2019 Essentials of Anaesthetic Equipment