Ammonia is a colourless gas with a characteristic pungent smell and hazardous in its concentrated form.
Chemical, physical and thermal properties of Ammonia, NH3:
Values at 25oC /77oF / 298 K and 1 atm., if not other temperature and pressure given.
If values are given for liquid ammonia at ambient temperature, the ammonia is pressurized above 1 atm.
For full table with Imperial units - rotate the screen!
|Acidity (pKa) at -33°C||32.5|
|Density, liquid at -28 °F/-33.35°C, 1 atm||40868||mol/m3||696||kg/m3||43.4||lb/ft3||1.35||slug/ft3|
|Density, liquid at 70 °F/21.1°C||36259||mol/m3||617.5||kg/m3||38.55||lb/ft3||1.198||slug/ft3|
|Gas constant, R||488.2||J/kg K||0.1356||Wh/(kg K)||90.74||ft lbf/lb °R||2919||ft lbf/slug °R|
|Gibbs free energy of formation, ΔGf||-16.6||kJ/mol||-975||kJ/kg||-0.42||Btu/lb|
|Heat (enthalpy) of combustion, ΔHc (gas)||382.8||kJ/mol||22477||kJ/kg||9.663||Btu/lb|
|Heat (enthalpy) of evaporation, ΔHv, at boiling point||23.37||kJ/mol||1372.0||kJ/kg||589.87||Btu/lb|
|Heat(enthalpy) of formation, ΔHf (gas)||-45.9||kJ/mol||-2695||kJ/kg||-1.16||Btu/lb|
|Heat (enthalpy) of fusion/melting, ΔHm||5.653||kJ/mol||332.3||kJ/kg||143||Btu/lb|
|Heat (enthalpy) of sublimation, ΔHS, at 180 K||31.2||kJ/mol||1832||kJ/kg||0.79||Btu/lb|
|Melting (freezing) point||195.42||K||-77.73||°C||-107.91||°F|
|pH of 0.01 N aqueous solution||10.6|
|pH of 0.1 N aqueous solution||11.1|
|pH of 1.0 N aqueous solution||11.6|
|Standard molar entropy, S° (gas) at 1 bar||192.77||J/mol K||11.32||kJ/kg K||0.002704||Btu/lb °F|
|Solubility in water, at 20°C||540||mg/ml|
|Solubility in water, at 24°C||482||mg/ml|
|Sound velocity in gas||415||m/s|
|Specific Gravity, gas (density relativ to air)||0.604|
|Specific heat (heat capacity), Cp (gas)||37.0||J/mol K||2.175||kJ/kg K||0.5200||Btu/lb°F
= cal/g K
|Specific heat (heat capacity), Cp (liquid)||80.8||J/mol K||4.744||kJ/kg K||1.133||Btu/lb°F
= cal/g K
|Specific heat ratio - Cp/Cv (gas)||1.32|
|Surface tension at 11.1°C/52.0°F||23.4||dynes/cm|
|Surface tension at 34.1°C/93.4°F||18.1||dynes/cm|
|Thermal Conductivity||0.026||W/m°C||0.015||Btu/hr ft °F|
|Triple point pressure||0.00609||MPa=MN/m2||0.0609||bar||0.0601||atm||0.883||psi=lbf/in2|
|Triple point temperature||195.5||K||-77.65||°C||-107.77||°F|
|Vapor (saturation) pressure||1.00||MPa=MN/m2||7500||mm Hg||9.869||atm||145.0||psi=lbf/in2|
|Vapor (saturation) pressure at -49.72°F/-45.4°C||0.0533||MPa=MN/m2||400||mm Hg||0.526||atm||7.73||psi=lbf/in2|
|Viscosity, dynamic (absolute) (gas)||0.0100||cP||6.72*10-6||lbm/ft s||0.209*10-6||lbf s/ft2|
|Viscosity, dynamic (absolute) at 27°C (liq)||0.1293||cP||86.89*10-6||lbm/ft s||2.70*10-6||lbf s/ft2|
|Viscosity, dynamic (absolute) at -33.5°C (liq)||0.255||cP||171.4*10-6||lbm/ft s||5.326*10-6||lbf s/ft2|
See also the following documents for changes in ammonia properties with changes in pressure and temperature:
- Density at varying temperature and pressure
- Dynamic and Kinematic Viscosity
- Liquid Ammonia - Thermal Properties at Saturation Pressure
- Prandtl number
- Properties at Gas-Liquid Equilibrium Conditions
- Specific heat
- Thermal Conductivity at Varying Temperature and Pressure
- Vapour Pressure at gas-liquid equilibrium
See also more about atmospheric pressure, and STP - Standard Temperature and Pressure & NTP - Normal Temperature and Pressure,
as well as Thermophysical properties of: Acetone, Acetylene, Air, Argon, Benzene, Butane, Carbon dioxide, Carbon monoxide, Ethane, Ethanol, Ethylene, Helium, Hydrogen, Hydrogen sulfide, Methane, Methanol, Nitrogen, Oxygen, Pentane, Propane, Toluene, Water and Heavy water, D2O.
Ammonia is a gas at standard conditions. However, at low temperature and/or high pressures the gas becomes a liquid. The phase diagram for ammonia shows the phase behavior with changes in temperature and pressure. The curve between the triple point and the critical point shows the ammonia boiling point with changes in pressure.
Below the triple point temperature, ammonia becomes a solid, this phase will also be present at very high pressure (> 10 000 bar) and ambient temperature.
At the critical point there is no change of state when pressure is increased or if heat is added.
The triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.
Solubility of Ammonia in Water
Boiling points of elements, products and chemical species at varying conditions.
Densities of solids, liquids and gases. Definitions and convertion calculators.
The study of fluids - liquids and gases. Involving velocity, pressure, density and temperature as functions of space and time.
Material properties of gases, fluids and solids - densities, specific heats, viscosities and more.
Melting and freezing points of elements and chemical species at varying conditions.
Work, heat and energy systems.
Viscosities of products and chemical species at varying conditions.
Chemical, physical and thermal properties of acetone, also called 2-propanone, dimethyl ketone and pyroacetic acid. Phase diagram included.
Thermal properties of air at different temperatures - density, viscosity, critical temperature and pressure, triple point, enthalpi and entropi, thermal conductivity and diffusivity and more.
Ammonia and health symptoms - smell and threat to life.
Thermodynamic properties of saturated and superheated ammonia R-717 like specific volume, enthalpy and entropy.
Online calculator, figures and tables showing dynamic (absolute) and kinematic viscosity of gasous and liquid ammonia at temperatures ranging from -73 to 425°C (-100 to 800°F) at pressure ranging from 1 to 1000 bara (14.5 - 14500 psia) - SI and Imperial Units.
Figures and table with changes in Prandtl number for ammonia with changes in temperature and pressure.
Figures and tables showing how the properties of liquid and gaseous ammonia changes along the boiling/condensation curve (temperature and pressure between triple point and critical point conditions). An ammonia phase diagram are included.
Online calculator, figures and tables showing specific heat, CP and CV, of gasous and liquid ammonia at temperatures ranging from -73 to 425°C (-100 to 800°F) at pressure ranging from 1 to 100 bara (14.5 - 1450 psia) - SI and Imperial Units.
Online calculator, figures and tables showing thermal conductivity of liquid and gaseous ammonia at temperatures ranging -70 to 425 °C (-100 to 800 °F) at atmospheric and higher pressure - Imperial and SI Units.
Figures and table with ammonia saturation pressure at boiling points, SI and Imperial units.
Online calculator with figures and tables showing density and specific weight of ammonia for temperatures ranging -50 to 425 °C (-50 to 800 °F) at atmospheric and higher pressure - Imperial and SI Units.
Chemical, physical and thermal properties of benzene, also called benzol. Phase diagram included.
Chemical, physical and thermal properties of carbon dioxide. Phase diagram included.
Critical temperatures and pressures for some common substances like air, alcohol, ether, oxygen and more.
Chemical, Physical and Thermal Properties of Ethane - C2H6.
Chemical, physical and thermal properties of ethylene, also called ethene, acetene and olefiant gas. Phase diagram included.
Thermodynamic properties of heavy water (D2O) like density, melting temperature, boiling temperature, latent heat of fusion, latent heat of evaporation, critical temperature and more.
Density, specific heat, thermal conductivity, viscosity and Prandtls no. of liquid ammonia at saturation pressure.
Specific heats for some common liquids and fluids - acetone, oil, paraffin, water and many more.
Chemical, Physical and Thermal Properties of Methane - CH4. Phase diagram included.
Chemical, physical and thermal properties of methanol, CH3OH (also called carbinol, wood alcohol, hydroxy methyl and methyl alcohol). Phase diagram included.
Chemical, physical and thermal properties of pentane, also called n-pentane. Phase diagram included.
Solubility of Ammonia, Argon, Carbon Dioxide, Carbon Monoxide, Chlorine, Ethane, Ethylene, Helium, Hydrogen, Hydrogen Sulfide, Methane, Nitrogen, Oxygen and Sulfur Dioxide in water.
Thermal properties of water at different temperatures like density, freezing temperature, boiling temperature, latent heat of melting, latent heat of evaporation, critical temperature and more.