Acetylene

• Formula: C₂H₂
• Molecular weight: 26.0373
• IUPAC Standard InChI: InChI=1S/C2H2/c1-2/h1-2H Copy

  
• IUPAC Standard InChIKey: HSFWRNGVRCDJHI-UHFFFAOYSA-N Copy
• CAS Registry Number: 74-86-2
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
  The 3d structure may be viewed using Java or Javascript.
• Other names: Ethyne; Ethine; Narcylen; C2H2; Acetylen; UN 1001; Vinylene
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Phase change data
  • Henry's Law data
  • Gas phase ion energetics data
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Vibrational and/or electronic energy levels
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Electron-Impact Ionization Cross Sections (on physics web site)
  • Gas Phase Kinetics Database
• Options:
  • Switch to SI units

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• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

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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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis

Enthalpy of vaporization

Antoine Equation Parameters

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

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Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Henry's Law 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 by: Rolf Sander

Henry's Law constant (water solution)

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

Gas phase ion energetics data

Go To: Top, Phase change data, Henry's Law data, Gas Chromatography, References, Notes

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
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
LL - Sharon G. Lias and Joel F. Liebman

View reactions leading to C₂H₂⁺ (ion structure unspecified)

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₂H^- +  =

By formula: C₂H^- + H⁺ = C₂H₂

Gas Chromatography

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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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Kovats' RI, non-polar column, isothermal

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Kovats' RI, non-polar column, custom temperature program

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Normal alkane RI, non-polar column, temperature ramp

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Normal alkane RI, non-polar column, custom temperature program

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References

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

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

Buckingham and Donaghy, 1982
Buckingham, J.; Donaghy, S.M., Dictionary of Organic Compounds: Fifth Edition, Chapman and Hall, New York, 1982, 1. [all data]

Maass and Wright, 1921
Maass, O.; Wright, C.H., SOME PHYSICAL PROPERTIES OF HYDROCARBONS CONTAINING TWO AND THREE CARBON ATOMS., J. Am. Chem. Soc., 1921, 43, 5, 1098-1111, https://doi.org/10.1021/ja01438a013 . [all data]

Morehouse and Maass, 1931
Morehouse, F.R.; Maass, O., The Preparationa and Physical Properties of Ethyl and Methyl Acetylene, Can. J. Res., 1931, 5, 306. [all data]

Maass and Russell, 1918
Maass, O.; Russell, J., Unsaturation and molecular compound formation, J. Am. Chem. Soc., 1918, 40, 1561-1573. [all data]

McIntosh, 1907
McIntosh, D., The physical properties of liquid and solid acetylene., J. Phys. Chem., 1907, 11, 306-17. [all data]

Clark and Din, 1950
Clark, A.M.; Din, F., Equilibria Between Solid, Liquid, and Gaseous Phases at Low Temperature binary systems acetylene - carbon dioxide, acetylene - ethylene and acetylene - ethane, Trans. Faraday Soc., 1950, 46, 901. [all data]

Tsonopoulos and Ambrose, 1996
Tsonopoulos, C.; Ambrose, D., Vapor-Liquid Critical Properties of Elements and Compounds. 6. Unsaturated Aliphatic Hydrocarbons, J. Chem. Eng. Data, 1996, 41, 645-656. [all data]

Goloborod'ko and Khodeeva, 1972
Goloborod'ko, N.P.; Khodeeva, S.M., Russ. J. Phys. Chem. (Engl. Transl.), 1972, 46, 235-7. [all data]

Khodeeva, 1966
Khodeeva, S.M., Visual Observation of Gas-Gas Mixture, Russ. J. Phys. Chem. (Engl. Transl.), 1966, 40, 1061-3. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Reid, 1972
Reid, Robert C., Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00, AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637 . [all data]

Ambrose and Townsend, 1964
Ambrose, D.; Townsend, R., Vapour pressure of acetylene, Trans. Faraday Soc., 1964, 60, 1025, https://doi.org/10.1039/tf9646001025 . [all data]

Ambrose, 1956
Ambrose, D., The vapour pressures and critical temperatures of acetylene and carbon dioxide, Trans. Faraday Soc., 1956, 52, 772, https://doi.org/10.1039/tf9565200772 . [all data]

Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E., The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [all data]

Ambrose and Townsend, 1964, 2
Ambrose, D.; Townsend, R., Vapour Pressure of Acetylene, Trans. Faraday Soc., 1964, 60, 1025-1029, https://doi.org/10.1039/tf9646001025 . [all data]

Ambrose, 1956, 2
Ambrose, D., The Vapour Pressures and Critical Temperatures of Acetylene and Carbon Dioxide, Trans. Faraday Soc., 1956, 52, 772-781, https://doi.org/10.1039/tf9565200772 . [all data]

Jones, 1960
Jones, A.H., Sublimation Pressure Data for Organic Compounds., J. Chem. Eng. Data, 1960, 5, 2, 196-200, https://doi.org/10.1021/je60006a019 . [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]

Burbo, 1943
Burbo, P.Z., Russ. J. Phys. Chem., 1943, 7, 286. [all data]

Miskiewicz, Rieser, et al., 2010
Miskiewicz, Stefan; Rieser, Klaus; Dorfmüller, Thomas, Thermodynamische Untersuchungen an kondensierten Phasen, Berichte der Bunsengesellschaft für physikalische Chemie, 2010, 80, 5, 395-405, https://doi.org/10.1002/bbpc.19760800504 . [all data]

Miskiewicz, Rieser, et al., 1976
Miskiewicz, S.; Rieser, K.; Dorfmuller, T., Thermodynamische Untersuchungen an kondensierten Phasen, Ber. Bunsen-Ges. Physik. Chem., 1976, 80, 5, 395, https://doi.org/10.1002/bbpc.19760800504 . [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]

Plessis and Marmet, 1986
Plessis, P.; Marmet, P., Electroionization study of acetylene and fragment ions, Int. J. Mass Spectrom. Ion Processes, 1986, 70, 23. [all data]

Hayaishi, Iwata, et al., 1982
Hayaishi, T.; Iwata, S.; Sasanuma, M.; Ishiguro, E.; Morioka, Y.; Iida, Y.; Nakamura, M., Photoionisation mass spectrometric study of acetylene in the VUV region, J. Phys. B:, 1982, 15, 79. [all data]

Rosmus, Botschwina, et al., 1981
Rosmus, P.; Botschwina, P.; Maier, J.P., On the ionic states of vinylidene and acetylene, Chem. Phys. Lett., 1981, 84, 71. [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]

Bieri, Schmelzer, et al., 1980
Bieri, G.; Schmelzer, A.; Asbrink, L.; Jonsson, M., Fluorine and the fluoroderivatives of acetylene and diacetylene studied by 30.4 nm He(II) photoelectron spectroscopy, Chem. Phys., 1980, 49, 213. [all data]

Suzuki and Maeda, 1978
Suzuki, I.H.; Maeda, K., Ionization efficiency curves of acetylene by mono-energetic electron impact, Adv. Mass Spectrom., 1978, 7, 182. [all data]

Suzuki and Maeda, 1977
Suzuki, I.H.; Maeda, K., Ionization efficiency curves of acetylene by electron impact, Mass Spectrosc. (Tokyo), 1977, 25, 223. [all data]

Bieri, Burger, et al., 1977
Bieri, G.; Burger, F.; Heilbronner, E.; Maier, J.P., Valence ionization enrgies of hydrocarbons, Helv. Chim. Acta, 1977, 60, 2213. [all data]

Van Veen and Plantenga, 1976
Van Veen, E.H.; Plantenga, F.L., Low-energy electron-impact excitation spectra of acetylene, Chem. Phys. Lett., 1976, 38, 493. [all data]

Reeher, Flesch, et al., 1976
Reeher, J.R.; Flesch, G.D.; Svec, H.J., The mass spectra and ionization potentials of the neutral fragments produced during the electron bombardment of aromatic compounds, Org. Mass Spectrom., 1976, 11, 154. [all data]

Carlier, Dubois, et al., 1975
Carlier, P.; Dubois, J.E.; Masclet, P.; Mouvier, G., Spectres de photoelectrons des alcynes, J. Electron Spectrosc. Relat. Phenom., 1975, 7, 55. [all data]

Parr and Taylor, 1973
Parr, G.R.; Taylor, J.W., A photoionization mass spectrometer utilizing a high intensity molecular beam sampling system and synchrotron radiation, Rev. Sci. Instrum., 1973, 44, 1578. [all data]

Dibeler and Walker, 1973
Dibeler, V.H.; Walker, J.A., Photoionization of acetylene near threshold, Int. J. Mass Spectrom. Ion Phys., 1973, 11, 49. [all data]

Brogli, Heilbronner, et al., 1973
Brogli, F.; Heilbronner, E.; Hornung, V.; Kloster-Jensen, E., 230. Die photoelektronen-spektren methyl-substituierter Acetylene, Helv. Chim. Acta, 1973, 56, 2171. [all data]

Lossing, 1970
Lossing, F.P., Threshold ionization of acetylene by monoenergetic electron impact, Intern. J. Mass Spectrom. Ion Phys., 1970, 5, 190. [all data]

Omura, Kaneko, et al., 1969
Omura, I.; Kaneko, T.; Yamada, Y.; Tanaka, K., Mass spectrometric studies of photoionization. IV. Acetylene and propyne, J. Phys. Soc. Japan, 1969, 27, 178. [all data]

Williams and Hamill, 1968
Williams, J.M.; Hamill, W.H., Ionization potentials of molecules and free radicals and appearance potentials by electron impact in the mass spectrometer, J. Chem. Phys., 1968, 49, 4467. [all data]

Collins, Winters, et al., 1968
Collins, J.H.; Winters, R.E.; Engerholm, G.G., Fine structure in energy-distribution-difference ionizationefficiency curves, J. Chem. Phys., 1968, 49, 2469. [all data]

Baker and Turner, 1968
Baker, C.; Turner, D.W., High resolution molecular photoelectron spectroscopy. III.Acetylenes and azaacetylenes, Proc. Roy. Soc. (London), 1968, A308, 19. [all data]

Brehm, 1966
Brehm, B., Massenspektrometrische Untersuchung der Photoionisation von Molekulen, Z. Naturforsch., 1966, 21a, 196. [all data]

Nicholson, 1965
Nicholson, A.J.C., Photoionization-efficiency curves. II. False and genuine structure, J. Chem. Phys., 1965, 43, 1171. [all data]

Melton and Hamill, 1964
Melton, C.E.; Hamill, W.H., Appearance potentials by the retarding potential-difference method for secondary ions produced by excited-neutral, excited ion-neutral, and ion-neutral reactions, J. Chem. Phys., 1964, 41, 1469. [all data]

Dibeler and Reese, 1964
Dibeler, V.H.; Reese, R.M., Mass spectrometric study of photoionization. I. Apparatus and initial observations on acetylene, acetylene-d₂, benzene, and benzene-d₆, J. Res. NBS, 1964, 68A, 409. [all data]

Watanabe and Namioka, 1956
Watanabe, K.; Namioka, T., Ionization potential of propyne, J. Chem. Phys., 1956, 24, 915. [all data]

Kusch, Hustrulid, et al., 1937
Kusch, P.; Hustrulid, A.; Tate, J.T., The dissociation of HCN, C₂H₂, C₂N₂ and C₂H₄ by electron impact, Phys. Rev., 1937, 52, 843. [all data]

Price, 1935
Price, W.C., The absorption spectra of acetylene, ethylene, and ethane in the far ultraviolet, Phys. Rev., 1935, 47, 444. [all data]

Bieri and Asbrink, 1980
Bieri, G.; Asbrink, L., 30.4-nm He(II) photoelectron spectra of organic molecules, J. Electron Spectrosc. Relat. Phenom., 1980, 20, 149. [all data]

Cavell and Allison, 1978
Cavell, R.G.; Allison, D.A., Photoelectron spectra of acetylene with He(I), He(II) , Zr M175»_{zeta}, MgK»α radiation sources, J. Chem. Phys., 1978, 69, 159. [all data]

Locht and Davister, 1995
Locht, R.; Davister, M., The dissociative ionization of C₂H₂. The C⁺, C₂⁺, and CH₂⁺ dissociation channels. The vinylidene ion as a transient?, Chem. Phys., 1995, 195, 443. [all data]

Cooper, Ibuki, et al., 1988
Cooper, G.; Ibuki, T.; Iida, Y.; Brion, C.E., Absolute dipole oscillator strengths for photoabsorption and the molecular and dissociative photoionization of acetylene, Chem. Phys., 1988, 125, 307. [all data]

Bloch, 1963
Bloch, A., Mass spectra of acetylene under high pressure in the ion source, Advan. Mass Spectrom., 1963, 2, 48. [all data]

Davister and Locht, 1995
Davister, M.; Locht, R., The dissociative ionization of C₂H₂ and C₂D₂. The [CH(CD)]⁺ dissociation channel. The H(D)C≡C(D)H binding energy, Chem. Phys., 1995, 191, 333. [all data]

Kloster-Jensen, Pascual, et al., 1970
Kloster-Jensen, E.; Pascual, C.; Vogt, J., Mass spectrometric studies of mono- and di-haloacetylenes,, Helv. Chim. Acta, 1970, 53, 2109. [all data]

Haney and Franklin, 1968
Haney, M.A.; Franklin, J.L., Correlation of excess energies of electron-impact dissociations with the translational energies of the products, J.Chem. Phys., 1968, 48, 4093. [all data]

Franklin and Munson, 1965
Franklin, J.L.; Munson, M.S.B., Ion-molecule reactions in methane-oxygen and acetylene-oxygen systems, Symp. Combust., 10th, Univ. Cambridge, Cambridge, Engl.,, 1965, 1964, 561. [all data]

Reid, Ballantine, et al., 1995
Reid, C.J.; Ballantine, J.A.; Andrews, S.R.; Harris, F.M., Charge inversion of ground-state and metastable-state C₂⁺ cations formed from electroionised C₂H₂ and C₂N₂, and a re-evaluation of the carbon dimer's ionisation energy, Chem. Phys., 1995, 190, 113. [all data]

Momigny and Derouane, 1968
Momigny, J.; Derouane, E., Fine structure in the first derivative of ionization curves obtained under electron impact, Advan. Mass Spectrom., 1968, 4, 607. [all data]

Field, Franklin, et al., 1957
Field, F.H.; Franklin, J.L.; Lampe, F.W., Reactions of gaseous ions. II. Acetylene, J. Am. Chem. Soc., 1957, 79, 2665. [all data]

Coats and Anderson, 1957
Coats, F.H.; Anderson, R.C., Thermodynamic data from electron-impact measurements on acetylene and substituted acetylenes, J. Am. Chem. Soc., 1957, 79, 1340. [all data]

Servais and Locht, 1995
Servais, C.; Locht, R., The appearance energy of C₂H⁺ from C₂H₂ revisited. A photoion-photoelectron coincidence spectroscopic determination, Chem. Phys. Lett., 1995, 236, 96. [all data]

Weitzel, Mahnert, et al., 1994
Weitzel, K.-M.; Mahnert, J.; Penno, M., ZEKE-PEPICO investigations of dissociation energies in ionic reactions, Chem. Phys. Lett., 1994, 224, 371. [all data]

Davister and Locht, 1994
Davister, M.; Locht, R., The dissociative electroionization of C₂H₂, C₂D₂ and C₂HD. Investigation of the [C₂H(D)]⁺ and [H(D)]⁺ dissociation channels. The (D)H-C₂H(D) binding energy, Chem. Phys., 1994, 189, 805. [all data]

Norwood and Ng, 1989
Norwood, K.; Ng, C.Y., A state-selected study of the unimolecular decompoisition of C₂H₂⁺(A,B) using the photoion photoelectron coincidence method, J. Chem. Phys., 1989, 91, 2898. [all data]

Ono and Ng, 1981
Ono, Y.; Ng, C.Y., The heat of formation of C₂H⁺, J. Chem. Phys., 1981, 74, 6985. [all data]

Eland, 1979
Eland, J.H.D., Dissociations of state-selected C₂H₂⁺, H₂S⁺ and D₂S⁺ ions studied by photoelectron-photoion coincidence spectroscopy, Int. J. Mass Spectrom. Ion Phys., 1979, 31, 161. [all data]

Dibeler, Walker, et al., 1973
Dibeler, V.H.; Walker, J.A.; McCulloh, K.E., Observations on hot bands in the molecular and dissociative photoionization of acetylene and the heat of formation of the ethynyl ion, J. Chem. Phys., 1973, 59, 2264. [all data]

Botter, Dibeler, et al., 1966
Botter, R.; Dibeler, V.H.; Walker, J.A.; Rosenstock, H.M., Experimental and theoretical studies of photoionization-efficiency curves for C₂H₂ and C₂D₂, J. Chem. Phys., 1966, 44, 1271. [all data]

Shiromaru, Achiba, et al., 1987
Shiromaru, H.; Achiba, Y.; Kimura, K.; Lee, Y.T., Determination of the C-H bond dissociation energies of ethylene and acetylene by observation of the threshold energies of H⁺ formation by synchrotron radiation, J. Phys. Chem., 1987, 91, 17. [all data]

Hively and Hinton, 1968
Hively, R.A.; Hinton, R.E., Variation of the retention index with temperature on squalane substrates, J. Gas Chromatogr., 1968, 6, 4, 203-217, https://doi.org/10.1093/chromsci/6.4.203 . [all data]

Hoekman, 1993
Hoekman, S.K., Improved gas chromatography procedure for speciated hydrocarbon measurements of vehicle emissions, J. Chromatogr., 1993, 639, 2, 239-253, https://doi.org/10.1016/0021-9673(93)80260-F . [all data]

Supelco, 2012
Supelco, CatalogNo. 24160-U, Petrocol DH Columns. Catalog No. 24160-U, 2012, retrieved from http://www.sigmaaldrich.com/etc/medialib/docs/Supelco/Datasheet/1/w97949.Par.0001.File.tmp/w97949.pdf. [all data]

Zenkevich, 2005
Zenkevich, I.G., Experimentally measured retention indices., 2005. [all data]

Chen and Feng, 2007
Chen, Y.; Feng, C., QSPR study on gas chromatography retention index of some organic pollutants, Comput. Appl. Chem. (China), 2007, 24, 10, 1404-1408. [all data]

Zenkevich and Rodin, 2004
Zenkevich, I.G.; Rodin, A.A., Gas chromatographic identification of some volatile toxic fluorine containing compounds by precalculated retention indices, J. Ecol. Chem. (Rus.), 2004, 13, 1, 22-28. [all data]

Flanagan, Streete, et al., 1997
Flanagan, R.J.; Streete, P.J.; Ramsey, J.D., Volatile Substance Abuse, UNODC Technical Series, No 5, United Nations, Office on Drugs and Crime, Vienna International Centre, PO Box 500, A-1400 Vienna, Austria, 1997, 56, retrieved from http://www.odccp.org/pdf/technical_series₁997-01-01₁.pdf. [all data]

Strete, Ruprah, et al., 1992
Strete, P.J.; Ruprah, M.; Ramsey, J.D.; Flanagan, R.J., Detection and identification of volatile substances by headspace capillary gas chromatography to aid the diagnosis of acute poisoning, Analyst, 1992, 117, 7, 1111-1127, https://doi.org/10.1039/an9921701111 . [all data]

Notes

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

• Symbols used in this document:
  

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  Pc	Critical pressure
  Ptriple	Triple point pressure
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Vc	Critical volume
  d(ln(kH))/d(1/T)	Temperature dependence parameter for Henry's Law constant
  k°H	Henry's Law constant at 298.15K
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔvapH	Enthalpy of vaporization
  ρc	Critical density

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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