Density of Gases Data
Densities and molecular weights of common gases like acetylene, air, methane, nitrogen, oxygen and others.
Densities, molecular weight and chemical formulas of some common gases can be found in the table below:
| Gas | Formula | Molecular weight | Density - ρ - | |
|---|---|---|---|---|
| (kg/m3) | (lb/ft3) | |||
| Acetylene (ethyne) | C2H2 | 26 | 1.0921) 1.1702) |
0.06821) 0.07292) |
| Air | 29 | 1.2051) 1.2932) |
0.07521) 0.08062) |
|
| Ammonia | NH3 | 17.031 | 0.7171) 0.7692) |
0.04481) 0.04802) |
| Argon | Ar | 39.948 | 1.6611) 1.78372) |
0.10371) 0.1113532) |
| Benzene | C6H6 | 78.11 | 3.486 | 0.20643 |
| Blast furnace gas | 1.2502) | 0.07802) | ||
| Butane | C4H10 | 58.1 | 2.4891) 2.52) |
0.15541) 0.1562) |
| Butylene (Butene) | C4H8 | 56.11 | 2.504 | 0.1482) |
| Carbon dioxide | CO2 | 44.01 | 1.8421) 1.9772) |
0.11501) 0.12342) |
| Carbon disulphide | 76.13 | |||
| Carbon monoxide | CO | 28.01 | 1.1651) 1.2502) |
0.07271) 0.07802) |
| Carbureted Water Gas | 0.048 | |||
| Chlorine | Cl2 | 70.906 | 2.9941) | 0.18691) |
| Coal gas | 0.582) | |||
| Coke Oven Gas | 0.0342) | |||
| Combustion products | 1.112) | 0.0692) | ||
| Cyclohexane | 84.16 | |||
| Digester Gas (Sewage or Biogas) | 0.062 | |||
| Ethane | C2H6 | 30.07 | 1.2641) | 0.07891) |
| Ethyl Alcohol | 46.07 | |||
| Ethyl Chloride | 64.52 | |||
| Ethylene | C2H4 | 28.03 | 1.2602) | 0.07862) |
| Helium | He | 4.02 | 0.16641) 0.17852) |
0.010391) 0.0111432) |
| N-Heptane | 100.20 | |||
| Hexane | 86.17 | |||
| Hydrogen | H2 | 2.016 | 0.08992) | 0.00562) |
| Hydrochloric Acid | 36.47 | 1.632) | ||
| Hydrogen Chloride | HCl | 36.5 | 1.5281) | 0.09541) |
| Hydrogen Sulfide | H2S | 34.076 | 1.4341) | 0.08951) |
| Krypton | 3.742) | |||
| Methane | CH4 | 16.043 | 0.6681) 0.7172) |
0.04171) 0.04472) |
| Methyl Alcohol | 32.04 | |||
| Methyl Butane | 72.15 | |||
| Methyl Chloride | 50.49 | |||
| Natural gas | 19.5 | 0.7 - 0.92) | 0.044 - 0.0562) | |
| Neon | Ne | 20.179 | 0.89992) | 0.0561792) |
| Nitric oxide | NO | 30.0 | 1.2491) | 0.07801) |
| Nitrogen | N2 | 28.02 | 1.1651) 1.25062) |
0.07271) 0.0780722) |
| Nitrogen Dioxide | NO2 | 46.006 | ||
| N-Octane | 114.22 | |||
| Nitrous Oxide | N2O | 44.013 | 0.1141) | |
| Nitrous Trioxide | NO3 | 62.005 | ||
| Oxygen | O2 | 32 | 1.3311) 1.42902) |
0.08311) 0.0892102) |
| Ozone | O3 | 48.0 | 2.142) | 0.125 |
| N-Pentane | 72.15 | |||
| Iso-Pentane | 72.15 | |||
| Propane | C3H8 | 44.09 | 1.8821) | 0.11751) |
| Propene (propylene) | C3H6 | 42.1 | 1.7481) | 0.10911) |
| R-11 | 137.37 | |||
| R-12 | 120.92 | |||
| R-22 | 86.48 | |||
| R-114 | 170.93 | |||
| R-123 | 152.93 | |||
| R-134a | 102.03 | |||
| Sasol | 0.032 | |||
| Sulfur | S | 32.06 | 0.135 | |
| Sulfur Dioxide | SO2 | 64.06 | 2.2791) 2.9262) |
0.17031) 0.18282) |
| Sulfur Trioxide | SO3 | 80.062 | ||
| Sulfuric Oxide | SO | 48.063 | ||
| Toluene | C7H8 | 92.141 | 4.111 | 0.2435 |
| Water Vapor, steam | H2O | 18.016 | 0.804 | 0.048 |
| Water gas (bituminous) | 0.054 | |||
| Xenon | 5.862) | |||
1) NTP - Normal Temperature and Pressure - is defined as 20 oC (293.15 K, 68 oF) and 1 atm ( 101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 30 in Hg, 760 torr)
2) STP - Standard Temperature and Pressure - is defined as 0 oC (273.15 K, 31 oF) and 1 atm (101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 30 in Hg, 760 torr)
- 1 lbm/ft3 = 16.018 kg/m3
- 1 kg/m3 = 0.0624 lbm/ft3
Note that even if pounds per cubic foot is often used as a measure of density in the U.S., pounds are really a measure of force, not mass. Slugs are the correct measure of mass. You can divide pounds per cubic foot by 32.2 for a rough value in slugs.
