Compound Information 

Name: hydrogen cyanide
Formula: CHN
Molar Mass: 27.026
Additional Names: formic anammonide
methanenitrile
formonitrile
carbon hydride nitride (CHN)
prussic acid
evercyn
hydrocyanic acid
Image of hydrogen cyanide

Please be patient while the web interface loads...

Property Availability 

For this compound, WTT contains critically evaluated recommendations for:
(Please note that if more than 50 points are used for regression, only the 50 most-constraining points are reported)

  • Triple point temperature
    • Triple point temperature (Crystal 1, Liquid, and Gas)
      14 experimental data points
    • Triple point temperature (Crystal 2, Crystal 1, and Gas)
      1 experimental data points
  • Normal boiling temperature (Liquid and Gas)
    • Critical temperature (Liquid and Gas)
      1 experimental data points
      • Critical pressure (Liquid and Gas)
        1 experimental data points
        • Boiling temperature (Liquid in equilibrium with Gas) as a function of Pressure
          Pressure from 18.7828 kPa to 4968.64 kPa
          • Phase boundary pressure
            • Phase boundary pressure (Liquid in equilibrium with Gas) as a function of Temperature
              Temperature from 259.871 K to 456.646 K
              48 experimental data points
            • Phase boundary pressure (Crystal 1 in equilibrium with Gas) as a function of Temperature
              Temperature from 194.565 K to 259.87 K
              20 experimental data points
          • Critical density (Liquid and Gas)
            1 experimental data points
            • Density
              • Density (Liquid in equilibrium with Gas) as a function of Temperature
                Temperature from 259.871 K to 456.646 K
                30 experimental data points
              • Density (Gas) as a function of Temperature and Pressure
                Temperature from 200.22 K to 448.225 K
                Pressure from 0.0007 kPa to 663.841 kPa
                10 experimental data points
              • Density (Gas in equilibrium with Liquid) as a function of Temperature
                Temperature from 340.33 K to 456.646 K
                11 experimental data points
            • Enthalpy of phase transition
              • Enthalpy of phase transition (Crystal 2 to Crystal 1 in equilibrium with Gas)
                1 experimental data points
              • Enthalpy of phase transition (Crystal 1 to Liquid in equilibrium with Gas)
                1 experimental data points
            • Enthalpy of vaporization or sublimation
              • Enthalpy of vaporization or sublimation (Liquid to Gas) as a function of Temperature
                Temperature from 259.871 K to 456.646 K
                1 experimental data points
              • Enthalpy of vaporization or sublimation (Crystal 1 to Gas) as a function of Temperature
                Temperature from 194.565 K to 259.87 K
            • Heat capacity at saturation pressure
              • Heat capacity at saturation pressure (Liquid in equilibrium with Gas) as a function of Temperature
                Temperature from 259.871 K to 447.513 K
                16 experimental data points
              • Heat capacity at saturation pressure (Crystal 2 in equilibrium with Gas) as a function of Temperature
                Temperature from 0.0002 K to 170.402 K
                50 experimental data points
              • Heat capacity at saturation pressure (Crystal 1 in equilibrium with Gas) as a function of Temperature
                Temperature from 170.403 K to 259.87 K
                28 experimental data points
            • Heat capacity at constant pressure (Ideal Gas) as a function of Temperature
              Temperature from 298 K to 1000 K
              • Enthalpy
                • Enthalpy (Crystal 2 in equilibrium with Gas) as a function of Temperature
                  Temperature from 0.0002 K to 170.402 K
                • Enthalpy (Crystal 1 in equilibrium with Gas) as a function of Temperature
                  Temperature from 170.403 K to 259.87 K
                • Enthalpy (Liquid in equilibrium with Gas) as a function of Temperature
                  Temperature from 259.871 K to 447.513 K
                • Enthalpy (Ideal Gas) as a function of Temperature
                  Temperature from 298 K to 1000 K
              • Entropy
                • Entropy (Crystal 2 in equilibrium with Gas) as a function of Temperature
                  Temperature from 0.0002 K to 170.402 K
                • Entropy (Crystal 1 in equilibrium with Gas) as a function of Temperature
                  Temperature from 170.403 K to 259.87 K
                • Entropy (Liquid in equilibrium with Gas) as a function of Temperature
                  Temperature from 259.871 K to 447.513 K
                  1 experimental data points
                • Entropy (Ideal Gas) as a function of Temperature and Pressure
                  Temperature from 298 K to 1000 K
              • Viscosity
                • Viscosity (Liquid in equilibrium with Gas) as a function of Temperature
                  Temperature from 263.158 K to 450 K
                  10 experimental data points
                • Viscosity (Gas) as a function of Temperature and Pressure
                  Temperature from 300 K to 680 K
              • Thermal conductivity
                • Thermal conductivity (Gas) as a function of Temperature and Pressure
                  Temperature from 300 K to 680 K
                • Thermal conductivity (Liquid in equilibrium with Gas) as a function of Temperature
                  Temperature from 260 K to 410 K

              About WTT 

              NIST/TRC Web Thermo Tables (WTT)
              NIST Standard Reference Subscription Database 3 - Professional Edition
              Version 2-2012-1-Pro

              This web application provides access to a collection of critically evaluated thermodynamic property data for pure compounds with a primary focus on organics. These data were generated through dynamic data analysis, as implemented in the NIST ThermoData Engine software package [1, 2, 3, 4, 5, 6]. Some critically evaluated data from the historical TRC Thermodynamic Tables archive [7, 8] are included, also. As of May 2012, the Professional Edition contains information on 28432 compounds and total of 531486 evaluated data points. The properties covered by both versions (32 total) are described in Properties and Implemented Models.

              Developed by Kenneth Kroenlein, Chris D. Muzny, Andrei F. Kazakov, Vladimir Diky, Robert D. Chirico, Joseph W. Magee, Ilmutdin Abdulagatov and Michael Frenkel.

              Thermodynamics Research Center (TRC)
              Thermophysical Properties Division
              National Institute of Standards and Technology
              Boulder CO 80305-3337

              Questions and comments should be addressed to Dr. Michael Frenkel .

              DISCLAIMER: The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high-quality copy of the database and to verify that the methods and data contained therein have been selected on the basis of sound scientific judgement. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the program and database.

              Distributed by:
              Standard Reference Data Program
              National Institute of Standards and Technology
              Gaithersburg MD 20899

              Compound Information
              Property Availability
              About this site
              NIST Chemistry WebBook