Physical Constants:

Standard Temperature and Pressure(STP)- as defined by the U.S. EPA:

Temperature: 20oC (68oF; 293K; 528oR)

Pressure: 1 atm (29.92 in Hg; 1013 mBar)

Gas volume per mole:

385.4 ft3/lb-mol(at STP)
22.4 l/mol(at STP)

Molecular Weights of
Commonly Emitted Gases
(g/mol and lb/lb-mol)
Oxygen 31.99
Carbon Dioxide 44.01
Nitrogen Oxides (as NO2) 46.05
Sulfur Dioxide 28.01
Carbon Monoxide 28.01
Methane 16.04
Propane 44.09
Benzene 78.1
Formaldehyde 30.03
Hydrogen Sulfide 34.08
Hydrogen Cyanide 27.025

 

You can find othe useful conversions and constants at:
http://www.epa.gov/eogapti1/bces/reference/reference.htm

931 Seaco Ct, Deer Park, TX 77536
Office 888.908.8235 • Fax 281.984.7137