helium (CAS 7440-59-7) – Thermophysical Properties
This page provides thermophysical, transport, safety, and environmental property data for helium, along with a property calculator for evaluating values at user-defined temperature and pressure conditions.
Related Calculators for helium
Input Conditions
Enter a pure component, temperature, and pressure.
Results
Calculated properties for the given state will appear here.
helium
Identification
| Atoms | He: 1 |
| CAS | 7440-59-7 |
| Formula | He |
| ID | helium |
| InChI | He |
| InChI Key | SWQJXJOGLNCZEY-UHFFFAOYSA-N |
| IUPAC Name | helium |
| Molecular Weight (kg/kmol) | 4.0026 |
| Phase | g |
| PubChem ID | 2.3987e+4 |
| SMILES | [He] |
| Synonyms |
Physical Properties
| Acentric factor | -0.3836 |
| Critical pressure (bar) | 2.2832 |
| Critical temperature (°C) | -267.955 |
| Critical volume (m³/kmol) | 0.0575252 |
| Dipole moment | 0 |
| Melting temperature (°C) | -272.2 |
| Normal boiling temperature (°C) | -268.926 |
State-dependent Properties
| Compressibility factor | 1 |
| Density (kg/m³) | 0.163603 |
| Dynamic viscosity (cP) | 0.0198456 |
| Joule–Thomson coefficient | 4.2132e-13 |
| Kinematic viscosity | 1.2130e-4 |
| Molar enthalpy (kJ/kmol) | 0 |
| Molar enthalpy of vaporization (kJ/kmol) | 0 |
| Molar heat capacity (kJ/(kmol·K)) | 20.7861 |
| Molar volume (m³/kmol) | 24.4654 |
| Parachor | |
| Poynting correction factor | |
| Prandtl number | 0.66359 |
| Saturation pressure (bar) | 1.6261e+23 |
| Saturation temperature (°C) | -268.926 |
| Solubility parameter | |
| Specific enthalpy of vaporization (kJ) | 0 |
| Specific gravity | 0.138126 |
| Specific heat capacity (kJ/kg·K) | 5.19316 |
| Surface tension | 0 |
| Thermal conductivity (W/m·K) | 0.155309 |
| Thermal diffusivity | 1.8280e-4 |
Safety Properties
| Autoignition temperature (°C) | -273.15 |
| Flash point temperature (°C) | -273.15 |
| Lower flammability limit | |
| Upper flammability limit | 0.235 |
Environmental Properties
| Global warming potential | |
| Ozone depletion potential |
Failed Properties:
| API gravity | Failed |
| Molar entropy (kJ/(kmol·K)) | Failed |
| Molar Gibbs free energy (kJ/kmol) | Failed |
| Specific enthalpy (kJ) | Failed |
| Specific entropy (kJ/kg·K) | Failed |
| Specific Gibbs free energy (kJ) | Failed |
About This Property Calculator
This tool provides a comprehensive set of thermophysical, safety, and environmental properties for helium. By default, the state-dependent properties like density, viscosity, and heat capacity are calculated at standard conditions of 25 °C (298.15 K) and 1 atm (101325 Pa).
How to Calculate Properties at Different Conditions
You can use the interactive calculator above to compute properties at your desired temperature and pressure. Simply enter your target values in the input fields and click the "Calculate Properties" button. The results table will update with the new values.
For example, to find the density of liquid helium at 50 °C and 2 bar, you would:
- Select your preferred unit system (e.g., Metric).
- Enter "50" into the Temperature field.
- Enter "2" into the Pressure field.
- Click "Calculate Properties."
The calculator will then display the updated density and other state-dependent properties for these specific conditions. This functionality is essential for process design, equipment sizing, and safety analysis in chemical engineering.