Compound Information 

Name: octadecane
Formula: C18H38
Molar Mass: 254.502
Additional Names: n-octadecane
Image of octadecane

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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)
      7 experimental data points
    • Triple point temperature (Crystal 2, Crystal 1, and Gas)
      3 experimental data points
  • Normal boiling temperature (Liquid and Gas)
    • Critical temperature (Liquid and Gas)
      3 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 3.33472e-005 kPa to 1244.6 kPa
          • Phase boundary pressure
            • Phase boundary pressure (Liquid in equilibrium with Gas) as a function of Temperature
              Temperature from 301.315 K to 747.6 K
              50 experimental data points
            • Phase boundary pressure (Crystal 1 in equilibrium with Liquid) as a function of Temperature
              Temperature from 301.315 K to 353.15 K
              14 experimental data points
          • Critical density (Liquid and Gas)
            • Density
              • Density (Liquid in equilibrium with Gas) as a function of Temperature
                Temperature from 301.315 K to 747.6 K
                50 experimental data points
              • Density (Gas) as a function of Temperature and Pressure
                Temperature from 400 K to 537 K
                Pressure from 0.0004 kPa to 425.045 kPa
              • Density (Gas in equilibrium with Liquid) as a function of Temperature
                Temperature from 601.852 K to 747.629 K
            • Enthalpy of phase transition (Crystal 1 to Liquid in equilibrium with Gas)
              5 experimental data points
              • Enthalpy of vaporization or sublimation (Liquid to Gas) as a function of Temperature
                Temperature from 301.315 K to 747.6 K
                • Heat capacity at saturation pressure
                  • Heat capacity at saturation pressure (Liquid in equilibrium with Gas) as a function of Temperature
                    Temperature from 301.315 K to 732.677 K
                    49 experimental data points
                  • Heat capacity at saturation pressure (Crystal 2 in equilibrium with Gas) as a function of Temperature
                    Temperature from 13 K to 237.028 K
                    50 experimental data points
                • Heat capacity at constant pressure (Ideal Gas) as a function of Temperature
                  Temperature from 200 K to 1000 K
                  • Enthalpy
                    • Enthalpy (Crystal 2 in equilibrium with Gas) as a function of Temperature
                      Temperature from 13 K to 237.028 K
                    • Enthalpy (Ideal Gas) as a function of Temperature
                      Temperature from 200 K to 1000 K
                  • Entropy
                    • Entropy (Crystal 2 in equilibrium with Gas) as a function of Temperature
                      Temperature from 13 K to 237.028 K
                    • Entropy (Ideal Gas) as a function of Temperature and Pressure
                      Temperature from 200 K to 1000 K
                    • Entropy (Liquid in equilibrium with Gas) as a function of Temperature
                      Temperature from 301.315 K to 732.677 K
                  • Refractive index (Liquid) as a function of Wavelength, Temperature, and Pressure
                    Wavelength from 589.26 nm to 632.8 nm
                    Temperature from 301.396 K to 343.124 K
                    14 experimental data points
                    • Surface tension (Liquid in equilibrium with Gas) as a function of Temperature
                      Temperature from 302.985 K to 352.973 K
                      12 experimental data points
                      • Viscosity
                        • Viscosity (Liquid in equilibrium with Gas) as a function of Temperature
                          Temperature from 303.134 K to 740 K
                          42 experimental data points
                        • Viscosity (Gas) as a function of Temperature and Pressure
                          Temperature from 590 K to 1120 K
                      • Thermal conductivity
                        • Thermal conductivity (Gas) as a function of Temperature and Pressure
                          Temperature from 607.037 K to 1120 K
                          2 experimental data points
                        • Thermal conductivity (Liquid in equilibrium with Gas) as a function of Temperature
                          Temperature from 312.991 K to 670 K
                          42 experimental data points
                      • Enthalpy of formation
                        • Enthalpy of formation (Gas)
                        • Enthalpy of formation (Liquid)
                        • Enthalpy of formation (Crystal)
                          1 experimental data points

                      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
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