Gases

Density NTP: Normal Temperature and Pressure
– Temperature: 20°C (293,15 K or 68°F)
– Pressure: 1 atm (101,325 kPa, 101,325 kN/m², 14,7 psia)

Density STP: Standard Temperature and Pressure
– Temperature: 0°C (273,15 K or 32°F)
– Pressure: 1 atm (101,325 kPa, 101,325 kN/m², 14,7 psia)

Density of Gases
Gas Density NTP (kg/m³) Density STP (kg/m³)
Acetylene – ethyne (C2H2) 1,092 1,170
Air 1,205 1,293
Ammonia (NH3) 0,717 0,769
Argon (Ar) 1,661 1,1780)
Benzene (C6H6) 3,486 3,486
Blast fumace gas - 1,250
Butane (C4H10) 2,489 2,500
Butylene – Butene (C4H8) 2,504 2,504
Carbon dioxide (CO2) 1,843 1,977
Carbon monoxide (CO) 1,165 1,250
Chlorine (Cl2) 2,994 3,210
Coal gas - 0,580
Combustion products - 1,110
Ethane (C2H6) 1,264 -
Ethylene (C2H4) - 1,260
Fluorine (F2) 1,574 1,700
Helium (He) 0,1664 0,1785
Hydrogen (H2) 0,0893 0,0899
Hydrochloric Acid - 1,630
Hydrogen Chloride (HCl) 1,528 -
Hydrogen Sulfide (H2S) 1,434 -
Krypton (Kr) - 3,740
Methane (CH4) 0,668 0,717
Natural gas - 0,7 – 0,9
Neon (Ne) - 0,8999
Nitric oxide (NO) 1,249 -
Nitrogen (N2) 1,165 1,2506
Oxygen (O2) 1,331 1,429
Ozone (O3) - 2,14
Propane (C3H8) 1,882 -
Propene – propylene (C3H6) 1,748 -
Radon (Rn) - 9,730
Sulfur Dioxide (SO2) 2,279 2,926
Toluene (C3H6) 4,111 4,111
Water Vapor, steam (H2O) 0,804 0,804
Xenon (Xe) - 5,890