Ammonia

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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Quantity Value Units Method Reference Comment
Δfgas-45.94 ± 0.35kJ/molReviewCox, Wagman, et al., 1984CODATA Review value
Δfgas-45.90kJ/molReviewChase, 1998Data last reviewed in June, 1977
Quantity Value Units Method Reference Comment
gas,1 bar192.77 ± 0.05J/mol*KReviewCox, Wagman, et al., 1984CODATA Review value
gas,1 bar192.77J/mol*KReviewChase, 1998Data last reviewed in June, 1977

Gas Phase Heat Capacity (Shomate Equation)

Cp° = A + B*t + C*t2 + D*t3 + E/t2
H° − H°298.15= A*t + B*t2/2 + C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 − E/(2*t2) + G
    Cp = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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View table.

Temperature (K) 298. to 1400.1400. to 6000.
A 19.9956352.02427
B 49.7711918.48801
C -15.37599-3.765128
D 1.9211680.248541
E 0.189174-12.45799
F -53.30667-85.53895
G 203.8591223.8022
H -45.89806-45.89806
ReferenceChase, 1998Chase, 1998
Comment Data last reviewed in June, 1977 Data last reviewed in June, 1977

Phase change data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Quantity Value Units Method Reference Comment
Tfus194.95KN/ATimmermans, 1921Uncertainty assigned by TRC = 0.3 K; TRC
Quantity Value Units Method Reference Comment
Ptriple0.06060barN/AFonseca and Lobo, 1989Uncertainty assigned by TRC = 0.00005 bar; TRC
Quantity Value Units Method Reference Comment
Tc405.4KN/ABrunner, 1988Uncertainty assigned by TRC = 0.1 K; TRC
Tc405.6KN/AHentze, 1977Uncertainty assigned by TRC = 5. K; TRC
Quantity Value Units Method Reference Comment
Pc113.00barN/ABrunner, 1988Uncertainty assigned by TRC = 0.05 bar; TRC

Enthalpy of vaporization

ΔvapH (kJ/mol) Temperature (K) Method Reference Comment
22.7308.N/AZander and Thomas, 1979Based on data from 293. to 392. K.; AC
23.5239.N/AOverstreet and Giauque, 1937Based on data from 199. to 241. K.; AC
23.4239.COverstreet and Giauque, 1937AC

Antoine Equation Parameters

log10(P) = A − (B / (T + C))
    P = vapor pressure (bar)
    T = temperature (K)

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Temperature (K) A B C Reference Comment
164.0 to 239.63.18757506.713-80.78Stull, 1947Coefficents calculated by NIST from author's data.
239.6 to 371.54.868861113.928-10.409Stull, 1947Coefficents calculated by NIST from author's data.

Enthalpy of sublimation

ΔsubH (kJ/mol) Temperature (K) Reference Comment
31.2177. to 195.Overstreet and Giauque, 1937AC

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:


Henry's Law data

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Rolf Sander

Henry's Law constant (water solution)

kH(T) = H exp(d(ln(kH))/d(1/T) ((1/T) - 1/(298.15 K)))
H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(kH))/d(1/T) = Temperature dependence constant (K)

H (mol/(kg*bar)) d(ln(kH))/d(1/T) (K) Method Reference Comment
27.2100.QN/AOnly the tabulated data between T = 273. K and T = 303. K from missing citation was used to derive kH and -Δ kH/R. Above T = 303. K the tabulated data could not be parameterized by equation (reference missing) very well. The partial pressure of water vapor (needed to convert some Henry's law constants) was calculated using the formula given by missing citation. The quantities A and α from missing citation were assumed to be identical.
61.4200.MN/A 
56.4100.MN/A 
56.4200.TN/A 
58.4100.TN/A 
58.4100.QN/A missing citation refer to several references in their list of Henry's law constants but they don't assign them to specific species.
78. MN/A 
62.4085.?N/AN/A 
53. QN/A missing citation gives missing citation as the source for the data. However, no data was found in that reference.
59.4400.XN/A 
76.3400.MN/A 
61.4200.LN/A 
10.1500.LN/A 
57.4100.XN/AThe value is taken from the compilation of solubilities by W. Asman (unpublished).
59.4100.XN/AThe value is taken from the compilation of solubilities by W. Asman (unpublished).
62. XN/AValue given here as quoted by missing citation.

Gas phase ion energetics data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to H3N+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)10.070 ± 0.020eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)853.6kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity819.0kJ/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
10.02PIQi, Sheng, et al., 1995T = 0K; LL
10.07 ± 0.01PIPECORuede, Troxler, et al., 1993LL
10.186TEReiser, Habenicht, et al., 1993LL
10.069 ± 0.002PILocht, Hottmann, et al., 1992LL
10.072 ± 0.010PILocht, Leyh, et al., 1991LL
10.2985 ± 0.0001TEHabenicht, 1989LL
10.45EIBaldwin, Loudon, et al., 1977LLK
10.2PEDebies and Rabalais, 1975LLK
10.18 ± 0.09PEAue, Webb, et al., 1975LLK
10.2EIMorrison and Traeger, 1973LLK
10.15PEPotts and Price, 1972LLK
10.18 ± 0.01PEWeiss and Lawrence, 1970RDSH
14.94 ± 0.03PEWeiss and Lawrence, 1970RDSH
10.14PEBranton, Frost, et al., 1969RDSH
14.92PEBranton, Frost, et al., 1969RDSH
10.16 ± 0.02PIPotapov, 1968RDSH
10.17PIChupka and Russell, 1968RDSH
10.162 ± 0.008PIDibeler, Walker, et al., 1966RDSH
10.166SWatanabe and Sood, 1965RDSH
10.16PEAl-Joboury and Turner, 1964RDSH
15.02PEAl-Joboury and Turner, 1964RDSH
10.15 ± 0.01PIWatanabe and Mottl, 1957RDSH
10.82PEBaumgartel, Jochims, et al., 1989Vertical value; LL
10.8PEBieri, Asbrink, et al., 1982Vertical value; LBLHLM
10.85PEKimura, Katsumata, et al., 1981Vertical value; LLK
11.3PECampbell, Liesegang, et al., 1979Vertical value; LLK
10.85PEDaamen and Oskam, 1978Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
H+18.57H2NPIQi, Sheng, et al., 1995LL
HN+28. ± 1.5H2/2HEIMuller and Schulz, 1990LL
HN+16.9 ± 0.1H2EILocht, Servais, et al., 1988LL
HN+17.2H2EIMorrison and Traeger, 1973LLK
NH+17.1 ± 0.1H2EIReed and Snedden, 1959RDSH
H2N+15.75HPIQi, Sheng, et al., 1995LL
H2N+15.60 ± 0.02HPIPECORuede, Troxler, et al., 1993LL
H2N+15.75HPILocht, Hottmann, et al., 1992LL
H2N+15.76 ± 0.05HPILocht, Servais, et al., 1988LL
H2N+15.76 ± 0.05HEILocht, Servais, et al., 1988LL
H2N+15.5HPIPECOPowis, 1981LLK
H2N+15.87 ± 0.13HDERPowis, 1981LLK
H2N+15.768 ± 0.004HPIMcCulloh, 1976LLK
H2N+15.0HEIMorrison and Traeger, 1973LLK
NH2+15.73 ± 0.02HPIDibeler, Walker, et al., 1966RDSH
NH2+16.0 ± 0.1HEIFoner and Hudson, 1958RDSH
N+≤22.5H2+HEIMorrison and Traeger, 1973LLK
N+22.6 ± 0.1H2+HEIReed and Snedden, 1959RDSH

De-protonation reactions

H2N- + Hydrogen cation = Ammonia

By formula: H2N- + H+ = H3N

Quantity Value Units Method Reference Comment
Δr1688.0 ± 1.2kJ/molD-EAWickham-Jones, Ervin, et al., 1989gas phase; B
Δr1688.5 ± 3.3kJ/molG+TSMacKay, Hemsworth, et al., 1976gas phase; B
Δr1683.2kJ/molN/ACheck, Faust, et al., 2001gas phase; HCrO3(t); ; ΔS(EA)=6.6; B
Quantity Value Units Method Reference Comment
Δr1656.8 ± 1.6kJ/molH-TSWickham-Jones, Ervin, et al., 1989gas phase; B
Δr1657.3 ± 2.9kJ/molIMREMacKay, Hemsworth, et al., 1976gas phase; B
Δr1654.4kJ/molN/ACheck, Faust, et al., 2001gas phase; HCrO3(t); ; ΔS(EA)=6.6; B

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Henry's Law data, Gas phase ion energetics data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Timmermans, 1921
Timmermans, J., The Freezing Points of Organic Substances IV. New Exp. Determinations, Bull. Soc. Chim. Belg., 1921, 30, 62. [all data]

Fonseca and Lobo, 1989
Fonseca, I.M.A.; Lobo, L.Q., Thermodynamics of liquid mixtures of xenon and methyl fluoride, Fluid Phase Equilib., 1989, 47, 249. [all data]

Brunner, 1988
Brunner, E., Fluid Mixtures at High Pressures VI. Phase Separation and Critical Phenomena in 18 (n-Alkane + Ammonia) and 4 (n-Alkane _ Methanol) Mixtures, J. Chem. Thermodyn., 1988, 20, 273. [all data]

Hentze, 1977
Hentze, G., Critical temperature measurement of liquids by means of differential thermal analysis, Thermochim. Acta, 1977, 20, 27-30. [all data]

Zander and Thomas, 1979
Zander, Manfred; Thomas, Wilhelm, Some thermodynamic properties of liquid ammonia: PVT data, vapor pressure, and critical temperature, J. Chem. Eng. Data, 1979, 24, 1, 1-2, https://doi.org/10.1021/je60080a003 . [all data]

Overstreet and Giauque, 1937
Overstreet, Roy; Giauque, W.F., Ammonia. The Heat Capacity and Vapor Pressure of Solid and Liquid. Heat of Vaporization. The Entropy Values from Thermal and Spectroscopic Data, J. Am. Chem. Soc., 1937, 59, 2, 254-259, https://doi.org/10.1021/ja01281a008 . [all data]

Stull, 1947
Stull, Daniel R., Vapor Pressure of Pure Substances. Organic and Inorganic Compounds, Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022 . [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Qi, Sheng, et al., 1995
Qi, F.; Sheng, L.; Zhang, Y.; Yu, S.; Li, W.-K., Experimental and theoretical study of the dissociation energies DO(H2N-H) and DO(H2N+-H) and other related quantities, Chem. Phys. Lett., 1995, 234, 450. [all data]

Ruede, Troxler, et al., 1993
Ruede, R.; Troxler, H.; Beglinger, C.; Jungen, M., The dissociation energies of the positive ions NH3+, NF3+, PH3+, PF3+ and PCl3+, Chem. Phys. Lett., 1993, 203, 477. [all data]

Reiser, Habenicht, et al., 1993
Reiser, G.; Habenicht, W.; Muller-Dethlefs, K., Zero kinetic energy (ZEKE) photoelectron spectroscopy of ammonia by nonresonant two-photon ionization from the neutral ground state, J. Chem. Phys., 1993, 98, 8462. [all data]

Locht, Hottmann, et al., 1992
Locht, R.; Hottmann, K.; Hagenow, G.; Denzer, W.; Baumgartel, H., The threhold-photoelectron spectrum of NH3, Chem. Phys. Lett., 1992, 190, 124. [all data]

Locht, Leyh, et al., 1991
Locht, R.; Leyh, B.; Denzer, W.; Hagenow, G.; Baumgartel, H., The photoionization of ammonia revisited. The vibrational autoionization of NH3 and its three isotopomers in the 10-12 eV photon energy range, Chem. Phys., 1991, 155, 407. [all data]

Habenicht, 1989
Habenicht, W., [Title unavailable], Ph.D. Thesis, Technische Universitat Munchen, 1989. [all data]

Baldwin, Loudon, et al., 1977
Baldwin, M.A.; Loudon, A.G.; Webb, K.S.; Cardnell, P.C., Charge location and fragmentation under electron impact. V-The ionization potentials of (methylated) phosphoramides, guanidines, formamides, acetamides, ureas and thioureas, Org. Mass Spectrom., 1977, 12, 279. [all data]

Debies and Rabalais, 1975
Debies, T.P.; Rabalais, J.W., Calculated photoionization cross-sections and angular distributions for the isoelectronic series Ne, HF, H2O, NH3, and CH4, J. Am. Chem. Soc., 1975, 97, 487. [all data]

Aue, Webb, et al., 1975
Aue, D.H.; Webb, H.M.; Bowers, M.T., Photoelectron spectrum and gas-phase basicity of manxine. Evidence for a planar bridgehead nitrogen, J. Am. Chem. Soc., 1975, 97, 4136. [all data]

Morrison and Traeger, 1973
Morrison, J.D.; Traeger, J.C., Ionization and dissociation by electron impact. II. NH3 and PH3, Int. J. Mass Spectrom. Ion Phys., 1973, 11, 277. [all data]

Potts and Price, 1972
Potts, A.W.; Price, W.C., Photoelectron spectra and valence shell orbital structures of groups V VI hydrides, Proc. R. Soc. London A:, 1972, 326, 181. [all data]

Weiss and Lawrence, 1970
Weiss, M.J.; Lawrence, G.M., Photoelectron spectroscopy of NH3 and ND3 using molecular beams, J. Chem. Phys., 1970, 53, 214. [all data]

Branton, Frost, et al., 1969
Branton, G.R.; Frost, D.C.; Herring, F.G.; McDowell, C.A.; Stenhouse, I.A., The ionization potentials of ammonia and ammonia-d3, measured by photoelectron spectroscopy, and an INDO calculation of these values, Chem. Phys. Lett., 1969, 3, 581. [all data]

Potapov, 1968
Potapov, V.K., Mechanism of ionic-molecular reactions, Dokl. Akad. Nauk SSSR, 1968, 183, 386, In original 843. [all data]

Chupka and Russell, 1968
Chupka, W.A.; Russell, M.E., Ion-molecule reactions of NH3+ by photoionization, J. Chem. Phys., 1968, 48, 1527. [all data]

Dibeler, Walker, et al., 1966
Dibeler, V.H.; Walker, J.A.; Rosenstock, H.M., Mass spectrometric study of photoionization. V.Water and ammonia, J.Res. NBS, 1966, 70A, 459. [all data]

Watanabe and Sood, 1965
Watanabe, K.; Sood, S.P., Absorption and photoionization coefficients of NH3 in the 580-1650 A region, Sci. Light (Tokyo), 1965, 14, 36. [all data]

Al-Joboury and Turner, 1964
Al-Joboury, M.I.; Turner, D.W., Molecular photoelectron spectroscopy. Part II. A summary of ionization potentials, J. Chem. Soc., 1964, 4434. [all data]

Watanabe and Mottl, 1957
Watanabe, K.; Mottl, J.R., Ionization potentials of ammonia and some amines, J. Chem. Phys., 1957, 26, 1773. [all data]

Baumgartel, Jochims, et al., 1989
Baumgartel, H.; Jochims, H.-W.; Ruhl, E.; Bock, H.; Dammel, R.; Minkwitz, J.; Nass, R., Photoelectron and photoionization mass spectra of the fluoramines NH3-nFn1, Inorg. Chem., 1989, 28, 943. [all data]

Bieri, Asbrink, et al., 1982
Bieri, G.; Asbrink, L.; Von Niessen, W., 30.4-nm He(II) photoelectron spectra of organic molecules, J. Electron Spectrosc. Relat. Phenom., 1982, 27, 129. [all data]

Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]

Campbell, Liesegang, et al., 1979
Campbell, M.J.; Liesegang, J.; Riley, J.D.; Leckey, R.C.G.; Jenkin, J.G.; Poole, R.T., The electronic structure of the valence bands of solid NH3 and H2O studied by ultraviolet photoelectron spectroscopy, J. Electron Spectrosc. Relat. Phenom., 1979, 15, 83. [all data]

Daamen and Oskam, 1978
Daamen, H.; Oskam, A., Bonding properties of some monosubstituted chromium and tungsten hexacarbonyls M(CO)5L (L=amine, substituted pyridine, azine), Inorg. Chim. Acta, 1978, 26, 81. [all data]

Muller and Schulz, 1990
Muller, U.; Schulz, G., Electron-impact dissociation of ammonia; formation of NH+ ions in excited states, Chem. Phys. Lett., 1990, 170, 401. [all data]

Locht, Servais, et al., 1988
Locht, R.; Servais, C.; Ligot, M.; Derwa, F.; Momigny, J., The dissociative electroionization of ammonia and ammonia-d3. I. The NH+ and NH2+ dissociation channels, Chem. Phys., 1988, 123, 443. [all data]

Reed and Snedden, 1959
Reed, R.I.; Snedden, W., The ionisation potential of NH, J. Chem. Soc., 1959, 4132. [all data]

Powis, 1981
Powis, I., Influence of angular momentum in the dissociation of NH3+, J. Chem. Soc. Faraday Trans. 2, 1981, 77, 1433. [all data]

McCulloh, 1976
McCulloh, K.E., Energetics and mechanisms of fragment ion formation in the photoionization of normal and deuterated water and ammonia, Int. J. Mass Spectrom. Ion Phys., 1976, 21, 333. [all data]

Foner and Hudson, 1958
Foner, S.N.; Hudson, R.L., Mass spectrometric detection of triazene and tetrazene and studies of the free radicals NH2, and N2H3, J. Chem. Phys., 1958, 29, 442. [all data]

Wickham-Jones, Ervin, et al., 1989
Wickham-Jones, C.T.; Ervin, K.M.; Ellison, G.B.; Lineberger, W.C., NH2 Electron Affinity, J. Chem. Phys., 1989, 91, 4, 2762, https://doi.org/10.1063/1.456994 . [all data]

MacKay, Hemsworth, et al., 1976
MacKay, G.J.; Hemsworth, R.S.; Bohme, D.K., Absolute gas-phase acidities of CH3NH2, C2H5NH2, (CH3)2NH, and (CH3)3N, Can. J. Chem., 1976, 54, 1624. [all data]

Check, Faust, et al., 2001
Check, C.E.; Faust, T.O.; Bailey, J.M.; Wright, B.J.; Gilbert, T.M.; Sunderlin, L.S., Addition of Polarization and Diffuse Functions to the LANL2DZ Basis Set for P-Block Elements, J. Phys. Chem. A,, 2001, 105, 34, 8111, https://doi.org/10.1021/jp011945l . [all data]


Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Henry's Law data, Gas phase ion energetics data, References