What does an oxygen cylinder contain?

• A. Compressed air
• B. Compressed nitrogen
• C. Oxygen under pressure
• D. Carbon dioxide

Answer: (C)

An oxygen cylinder is specifically designed to store oxygen gas at high pressures. This means that the gas inside the cylinder is pure oxygen that has been compressed into a smaller volume, allowing for easy transport and access to the oxygen in medical or emergency situations.

Oxygen is essential in various medical contexts, such as respiratory support and advanced life support, and using it from a cylinder allows for precise delivery during treatment. The cylinder itself is built to withstand high pressures, ensuring safety during use.

The other options do not accurately describe the contents of an oxygen cylinder. Compressed air contains a mix of gases, primarily nitrogen and oxygen, while compressed nitrogen and carbon dioxide cylinders serve different purposes in medical and industrial applications. Thus, choosing an answer that specifies oxygen under pressure clearly highlights the unique and specific function of an oxygen cylinder in providing pure oxygen for therapeutic use.