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Other Properties
Density of liquid: 0.6818 at -33.35 deg C, 1 atm; 0.6585 at -15 deg C, 2.332 atm; 0.6386 at 0 deg C, 4.238 atm; 0.6175 at 15 deg C, 7.188 atm; 0.5875 at 35 deg C, 13.321 atm
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013. 88.
Critical molar volume: 69.8 cu cm/mol
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015. 6-83.
Specific heat, J/kg-K: 2097.2 at 0 deg C; 2226.2 at 100 deg C; 2105.6 at 200 deg C
Eggeman T; Ammonia. Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2016). New York, NY: John Wiley & Sons. Online Posting Date: April 16, 2010.
Specific gravity: 0.690 at -40 deg C; 0.639 at 0 deg C; 0.580 at 40 deg C
Eggeman T; Ammonia. Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2016). New York, NY: John Wiley & Sons. Online Posting Date: April 16, 2010.
Dipole moment, gas: 4.9x10-30 C m; 1.47 D
Braker W, Mossman A; Matheson Gas Data Book 6th ED p.23 (1980).
Heat capacity 8.38 cal/mol/deg at 25 deg C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013. 88.
1 ppm = 0.70 mg/cu m
NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: <http://www.cdc.gov/niosh/npg>.
Aqueous ammonia: pKb 4.767, Kb 1.710X10-5 at 20 deg C; pKb 4.751, Kb 1.774X10-5 at 25 deg C; pKb 4.740, Kb 1.820X10-5 at 30 deg C
Weast, R.C. (ed.) Handbook of Chemistry and Physics, 68th ed. Boca Raton, Florida: CRC Press Inc., 1987-1988. D-163.
Ionization potential = 10.070 eV
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015. 10-203.
Density of aqueous solutions at 20 deg C/4 deg C: 0.9939 (1%), 0.9811 (4%), 0.9651 (8%), 0.9362 (16%), 0.9229 (20%), 0.9101 (24%), 0.8980 (28%)
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013. 88.
Density: 0.7710 g/L (gas); 0.89801 g/L at 20 deg C (28% aqueous solution)
ATSDR; Toxicological Profile for Ammonia. Atlanta, GA: Agency for Toxic Substances and Disease Registry, US Public Health Service (2004). Available from, as of July 5, 2016: <http://www.atsdr.cdc.gov/toxprofiles/index.asp/>.
Lighter than air; easily liquified by pressure; spacial volume: 22.7 cu ft at 70 deg C
Larranaga, M.D., Lewis, R.J. Sr., Lewis, R.A.; Hawley's Condensed Chemical Dictionary 16th Edition. John Wiley & Sons, Inc. Hoboken, NJ 2016. 75.
Mixtures of ammonia and air will explode when ignited under favorable conditions, but ammonia is generally regarded as nonflammable; solution of ammonia in water is exothermic; one liter of gas weighs 0.7714 g
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013. 88.
Freezing point of aqueous solutions, deg C: -2.9 (4%), -8.1 (8%), -23.1 (16%), -34.9 (20%), -44.5 (24%), -69.2 (28%)
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013. 88.
Heat of formation: -45.9 kJ/mol; Gibbs energy of formation: -16.4 kJ/mol; molar entropy: 192.8 J/mol-K; molar heat capacity at constant pressure: 35.1 J/mol-K at 298.15 K
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015. 5-13.
Vapor pressure: 1 Pa at -139 deg C, 10 Pa at -127 deg C, 100 Pa at -112 deg C; 1 kPa at -94.5 deg C (solids); 10 kPa at -71.3 deg C, 100 kPa at -33.6 deg C (liquid)
Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015. 6-92.
Henry's Law constant = 1.61X10-5 atm cu-m/mole at 25 deg C
Betterton EA; pp. 1-50 in Gaseous Pollutants: Characterization and Cycling, Nriagu JO, Ed. John Wiley & Sons, Inc. (1992).
Hydroxyl radical reaction rate constant = 1.60X10-13 cu m/molec-sec at 25 deg C
NIST; NIST Chemistry WebBook. Ammonia(7664-41-7). NIST Gas Phase Kinetics Database No. 69, Sept 2013 Release. Washington, DC: US Sec Commerce. Available from, as of July 5, 2016: <http://webbook.nist.gov/>.
