Hydrogen cyanide

• Formula: CHN
• Molecular weight: 27.0253
• IUPAC Standard InChI: InChI=1S/CHN/c1-2/h1H Copy

  
• IUPAC Standard InChIKey: LELOWRISYMNNSU-UHFFFAOYSA-N Copy
• CAS Registry Number: 74-90-8
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: Hydrocyanic acid; AC; Blausaeure (German); Carbon hydride nitride (CHN); Formic anammonide; Formonitrile; HCN; Prussic Acid; Cyclon; Acide cyanhydrique; Acido cianidrico; Aero Liquid HCN; Blausaeure; Blauwzuur; Cyaanwaterstof; Cyanwasserstoff; Cyclone B; Cyjanowodor; Evercyn; NA 1051; Prussic acid, unstabilized; Rcra waste number P063; UN 1051; Zaclondiscoids; Carbon hydride nitride; Zootic acid; Agent AC; Nitrilomethane
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• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • IR Spectrum
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Phase change data
  • Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 92
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering data
  • Mass spectrum (electron ionization)
  • Gas Chromatography
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Gas Phase Kinetics Database
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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.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = 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
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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Condensed 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.

Data compiled by: Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of liquid

IR Spectrum

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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: Coblentz Society, Inc.

Spectrum

A digitized version of this spectrum is not currently available.

Additional Data

Vibrational and/or electronic energy levels

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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: Takehiko Shimanouchi

Symmetry:   C_∞ν     Symmetry Number σ = 1

Source: Shimanouchi, 1972

Notes

References

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

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

Giauque and Ruehrwein, 1939
Giauque, W.F.; Ruehrwein, R.A., The entropy of hydrogen cyanide. Heat capacity, heat of vaporization and vapor pressure. Hydrogen bond polymerization of the gas in chains of indefinite length, J. Am. Chem. Soc., 1939, 61, 2626-2633. [all data]

Shimanouchi, 1972
Shimanouchi, T., Tables of Molecular Vibrational Frequencies Consolidated Volume I, National Bureau of Standards, 1972, 1-160. [all data]

Notes

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• Symbols used in this document:
  

  Cp,liquid	Constant pressure heat capacity of liquid
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  S°liquid	Entropy of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions

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