Compound Information 

Name: helium
Formula: He
Molar Mass: 4.002602
Additional Names: helium-4
o-helium
p-helium
atomic helium
Image of helium

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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)

  • 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 5.04276 kPa to 227.6 kPa
          • Phase boundary pressure
            • Phase boundary pressure (Liquid in equilibrium with Gas) as a function of Temperature
              Temperature from 2.1768 K to 5.19529 K
              41 experimental data points
            • Phase boundary pressure (Crystal 1 in equilibrium with Liquid) as a function of Temperature
              Temperature from 1.28 K to 60.867 K
              50 experimental data points
          • Critical density (Liquid and Gas)
            2 experimental data points
            • Density
              • Density (Liquid in equilibrium with Gas) as a function of Temperature
                Temperature from 2.1768 K to 5.19529 K
                47 experimental data points
              • Density (Gas in equilibrium with Liquid) as a function of Temperature
                Temperature from 2.1768 K to 5.19529 K
                24 experimental data points
              • Density (Liquid) as a function of Temperature and Pressure
                Temperature from 2.1768 K to 5.19538 K
                Pressure from 1 kPa to 1000000 kPa
                50 experimental data points
              • Density (Gas) as a function of Temperature and Pressure
                Temperature from 2.1768 K to 2000 K
                Pressure from 1 kPa to 227.6 kPa
                50 experimental data points
            • Isobaric coefficient of expansion
              • Isobaric coefficient of expansion (Liquid) as a function of Temperature and Pressure
                Temperature from 2.1768 K to 5.19538 K
                Pressure from 1 kPa to 1000000 kPa
              • Isobaric coefficient of expansion (Gas) as a function of Temperature and Pressure
                Temperature from 2.1768 K to 2000 K
                Pressure from 1 kPa to 227.6 kPa
            • Isothermal compressibility
              • Isothermal compressibility (Liquid) as a function of Temperature and Pressure
                Temperature from 2.1768 K to 5.19538 K
                Pressure from 1 kPa to 1000000 kPa
              • Isothermal compressibility (Gas) as a function of Temperature and Pressure
                Temperature from 2.1768 K to 2000 K
                Pressure from 1 kPa to 227.6 kPa
            • Thermal pressure coefficient
              • Thermal pressure coefficient (Liquid) as a function of Temperature and Pressure
                Temperature from 2.1768 K to 5.19538 K
                Pressure from 1 kPa to 1000000 kPa
              • Thermal pressure coefficient (Gas) as a function of Temperature and Pressure
                Temperature from 2.1768 K to 2000 K
                Pressure from 1 kPa to 227.6 kPa
            • 2nd virial coefficient (Gas) as a function of Temperature
              Temperature from 2.1768 K to 2000 K
              50 experimental data points
              • 3rd virial coefficient (Gas) as a function of Temperature
                Temperature from 2.1768 K to 2000 K
                50 experimental data points
                • Enthalpy of vaporization or sublimation (Liquid to Gas) as a function of Temperature
                  Temperature from 2.1768 K to 5.19529 K
                  6 experimental data points
                  • Heat capacity at saturation pressure (Liquid in equilibrium with Gas) as a function of Temperature
                    Temperature from 2.1768 K to 5 K
                    • Heat capacity at constant pressure
                      • Heat capacity at constant pressure (Ideal Gas) as a function of Temperature
                        Temperature from 200 K to 1000 K
                      • Heat capacity at constant pressure (Liquid) as a function of Temperature and Pressure
                        Temperature from 2.1768 K to 5.19538 K
                        Pressure from 1 kPa to 1000000 kPa
                      • Heat capacity at constant pressure (Gas) as a function of Temperature and Pressure
                        Temperature from 2.1768 K to 2000 K
                        Pressure from 1 kPa to 227.6 kPa
                    • Enthalpy (Ideal Gas) as a function of Temperature
                      Temperature from 200 K to 1000 K
                      • Adiabatic compressibility
                        • Adiabatic compressibility (Liquid) as a function of Temperature and Pressure
                          Temperature from 2.1768 K to 5.19538 K
                          Pressure from 1 kPa to 1000000 kPa
                        • Adiabatic compressibility (Gas) as a function of Temperature and Pressure
                          Temperature from 2.1768 K to 2000 K
                          Pressure from 1 kPa to 227.6 kPa
                      • Pressure coefficient of enthalpy (Liquid) as a function of Temperature and Pressure
                        Temperature from 2.1768 K to 5.19538 K
                        Pressure from 1 kPa to 1000000 kPa
                        • Joule-Thomson coefficient (Gas) as a function of Temperature and Pressure
                          Temperature from 2.1768 K to 2000 K
                          Pressure from 1 kPa to 227.6 kPa
                          • Speed of sound
                            • Speed of sound (Gas in equilibrium with Liquid) as a function of Temperature
                              Temperature from 2.1768 K to 5.19529 K
                              20 experimental data points
                            • Speed of sound (Liquid) as a function of Temperature and Pressure
                              Temperature from 2.1768 K to 5.19538 K
                              Pressure from 1 kPa to 1000000 kPa
                            • Speed of sound (Gas) as a function of Temperature and Pressure
                              Temperature from 2.1768 K to 2000 K
                              Pressure from 1 kPa to 227.6 kPa
                              50 experimental data points
                            • Speed of sound (Liquid in equilibrium with Gas) as a function of Temperature
                              Temperature from 2.1768 K to 5.19529 K
                          • Surface tension (Liquid in equilibrium with Gas) as a function of Temperature
                            Temperature from 2.1768 K to 5.19529 K
                            16 experimental data points
                            • Viscosity
                              • Viscosity (Gas) as a function of Temperature and Pressure
                                Temperature from 2.1768 K to 2000 K
                                Pressure from 0.1 kPa to 227.6 kPa
                                376 experimental data points
                              • Viscosity (Liquid in equilibrium with Gas) as a function of Temperature
                                Temperature from 2.1768 K to 5 K
                                14 experimental data points
                              • Viscosity (Liquid) as a function of Temperature and Pressure
                                Temperature from 2.1768 K to 5.19538 K
                                Pressure from 0.1 kPa to 100000 kPa
                                14 experimental data points
                            • Thermal conductivity
                              • Thermal conductivity (Liquid) as a function of Temperature and Pressure
                                Temperature from 2.1768 K to 5.19538 K
                                Pressure from 0.1 kPa to 100000 kPa
                                15 experimental data points
                              • Thermal conductivity (Gas) as a function of Temperature and Pressure
                                Temperature from 2.1768 K to 2000 K
                                Pressure from 0.1 kPa to 227.6 kPa
                                50 experimental data points
                              • Thermal conductivity (Liquid in equilibrium with Gas) as a function of Temperature
                                Temperature from 2.1768 K to 5 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

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