Why is oxygen stored in large tanks as a liquid?

• A. To increase its density
• B. Because it is easier to transport
• C. Because 1 cubic ft at -183C produces 860 cubic ft of gas at 21C
• D. To reduce the cost of production

Answer: (C)

Oxygen is stored in large tanks as a liquid primarily because of the significant volume increase when it is allowed to expand into a gas under standard temperature and pressure conditions. At extremely low temperatures, specifically around -183 degrees Celsius, oxygen can be liquefied. When this liquid oxygen is then allowed to warm to room temperature, it expands enormously—one cubic foot of liquid oxygen will generate approximately 860 cubic feet of gaseous oxygen. This dramatic expansion makes it highly efficient to store oxygen in its liquid form, as it allows for a greater amount of oxygen to be packed into a smaller volume, facilitating easier storage and transportation.

The other aspects of why oxygen might be stored as a liquid, such as increasing density or reducing production costs, are not the primary reasons for its storage method. While it can be easier to transport liquid oxygen in a condensed form, the predominant advantage is the substantial increase in gas volume upon expansion.