Register December 2011 No. 672
Chapter SPS 343
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
Published under s. 35.93, Stats. Updated on the first day of each month. Entire code is always current. The Register date on each page is the date the chapter was last published.