Isothermal Properties for Ammonia
- Fluid Data
- Auxiliary Data
- Additional Information
- Important Information About This Data
- Other Data Available:
The following adjustments were made to the specified data range:
- The specified increment was adjusted to limit the number of points calculated.
Isothermal Data for T = 273.16 K
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Reference States, default for fluid
|Enthalpy||H = 28.945714 kJ/mol at 300.0 K and 0.0010 MPa.|
|Entropy||S = 159.336663 J/mol*K at 300.0 K and 0.0010 MPa.|
Additional fluid properties
|Critical temperature (Tc)||405.40 K|
|Critical pressure (Pc)||11.3330 MPa|
|Critical density (Dc)||13.2118 mol/l|
|Normal boiling point||239.823 K|
|Dipole moment||1.470 Debye|
Equation of state and auxiliary model
Tillner-Roth, R.; Harms-Watzenberg, F.; Baehr, H.D., Eine neue Fundamentalgleichung für Ammoniak., DKV-Tagungsbericht, 1993, 20, 167-181. [all data]
Ahrendts, J.; Baehr, H.D., The Thermodynamic Properties of Ammonia, VDI-Forsch., 1979, 596, 0. [all data]
Tufeu, R.; Ivanov, D.Y.; Garrabos, Y.; Le Neindre, B., Thermal conductivity of ammonia in a large temperature and pressure range including the critical region, Ber. Bunsenges. Phys. Chem., 1984, 88, 422-427. [all data]
Viscosity and auxiliary model
Fenghour, A.; Wakeham, W.A.; Vesovic, V.; Watson, J.T.R.; Millat, J.; Vogel, E., The viscosity of ammonia, J. Phys. Chem. Ref. Data, 1995, 24, 1649-1667. [all data]
Durrant, A.A.; Pearson, T.G.; Robinson, P.L., Physical relationships amongst the hydrides of elements of the fifth group with special reference to association in these compounds, Journal of the Chemical Society (part 1), 1934, 730-735. [all data]
Laine, P., Kaeltemaschinen und -apparate: Pruefung von Kaeltemaschineteilen auf Dichtheit, Kaeltetechnik, 1953, 6, 173. [all data]
Stairs, R.A.; Sienko, M.J., Surface tension of ammonia and of solutions of alkalai halides in ammonia, J. Am. Chem. Soc., 1956, 78, 920-923. [all data]
Haar, L.; Gallagher, J.S., Thermodynamic Properties of Ammonia, J. Phys. Chem. Ref. Data, 1978, 7, 3, 635-792. [all data]
Equation of state
The uncertainties of the equation of state are 0.2% in density, 2% in heat capacity, and 2% in the speed of sound, except in the critical region. The uncertainty in vapor pressure is 0.2%.
Cp0/R = (2/9)*a3*Tr**(-1/3) - (15/4)*a4*Tr**(3/2) - (77/16)*a5*Tr**(7/4) where the ai are the original coefficients given by T-R and Tr = T/Tc
A patch has been added to the Tufeu formulation to avoid infinite values of the thermal conductivity around the critical temperature at ANY density. The patch affects the region between 404.4 and 406.5 K and rho<9.6 or rho>18 mol/l.
The uncertainty in thermal conductivity is 2%.
The uncertainty varies from 0.5% for the viscosity of the dilute gas phase at moderate temperatures to about 5% for the viscosity at high pressures and temperatures.
Important Information About This Data
The data above are from an older version of the NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP version 7). We will be updating our site to use the newer version (version 9.1) of this database in the the next couple of months. Information on REFPROP version 9.1 can be found here. REFPROP version 9.1 includes additional data and features not available from this site.
- Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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