Register December 2011 No. 672
APPENDIX
The material contained in this appendix is for clarification and general information only.
Physical Properties of Ammonia
Molecular symbol NH3
Molecular weight 17.031
Boiling point at one atmosphere* -28°F
Melting point one atmosphere* -107.9°F
Critical temperature 271.4°F
Critical pressure 1657 psia
Latent heat at -28°F and one atmosphere* 589.3 Btu/lb
Relative density of vapor compared to dry air at 32°F and one atmosphere* 0.5970
Vapor density at -28°F and one atmosphere* 0.05555 lb/ft3
Specific gravity of liquid at -28°F compared to water at 39.2°F 0.6819
Weight per gallon of liquid at -28°F 5.69 lbs/gallon
Liquid density at -28°F and one atmosphere 42.57 lbs/ft3
Specific volume of vapor at 32°F and one atmosphere
20.78 ft3/lb
Flammable limits by volume in air at atmospheric pressure 16% to 25%
Ignition Temperature (in a standard quartz container) 1562°
F
Specific Heat, Gas, at 59°F and one atmosphere*
at constant pressure, Cp 0.5232 Btu/lb
°F
at constant volume, Cv 0.3995 Btu/lb
°F
*One atmosphere = 14.7 psia
