Question

Find the gases which is the densest at standard temperature and pressure.

• A. Helium
• B. Argon
• C. Carbon dioxide
• D. Xenon
• E. Nitrogen

Answer 1

Answer: (D)

The gas which is the densest at standard temperature and pressure is xenon.
At standard temperature and pressure, pure xenon gas has a density of 5.761 kg/m${}^3$, about 4.5 times the surface density of the earth's atmosphere, 1.217 kg/m${}^3$. As a liquid, xenon has a density of up to 3.100 g/mL, with the maximum density occurring at the triple point.