Yes, pure oxygen is slightly heavier than air.
While often perceived as light because it's a gas, pure oxygen (O₂) has a density that is greater than the density of the air we breathe. Let's break down why:
-
Density of Pure Oxygen: At 273 K (0°C) and 1 atmosphere of pressure, the density of pure oxygen is approximately 1.429 g/L (grams per liter).
-
Density of Air: The density of air under the same conditions is approximately 1.29 g/L.
-
Comparison: Since 1.429 g/L is greater than 1.29 g/L, pure oxygen is denser, and therefore heavier, than air.
This difference in density is due to the molar mass of oxygen molecules compared to the average molar mass of the gases that make up air (primarily nitrogen and oxygen, but also including argon and other trace gases).
In summary, while oxygen is a gas, its density makes it slightly heavier than the air we breathe.
