Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

This is an AMP page - Open full page! for all features.

Hydrogen - Thermophysical Properties

Sponsored Links

Hydrogen, H2, is a colorless, odorless gas.

Hydrogen is easily ignited. Once ignited it burns with a pale blue, almost invisible flame. The vapors are lighter than air. It is flammable over a wide range of vapor/air concentrations. Hydrogen is not toxic but is a simple asphyxiate by the displacement of oxygen in the air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket.

Hydrogen is used to make other chemicals, in petroleum refining and in oxyhydrogen welding and cutting.

The phase diagram of hydrogen is shown below the table.

Chemical, physical and thermal properties of hydrogen:
Values at 25 oC (77 o F, 298 K) and atmospheric pressure

Hydrogen - Thermophysical Properties
Molecular Weight 2.016
Specific Gravity , air = 1 0.070
Specific Volume ( ft3 /lb, m3 /kg ) 194, 12.1
Density of liquid at atmospheric pressure ( lb/ft3 , kg/m3 ) 4.43, 71.0
Absolute Viscosity ( lb m /ft s, centipoises ) 6.05 10-6 , 0.009
Sound velocity in gas ( m/s ) 1315
Specific Heat - c p - ( Btu/lb o F or cal/g oC, J/kgK ) 3.42, 14310
Specific Heat Ratio - c p /c v 1.405
Gas constant - R - ( ft lb/lb o R, J/kg oC ) 767, 4126
Thermal Conductivity ( Btu/hr ft o F, W/m oC ) 0.105, 0.182
Boiling Point - saturation pressure 14.7 psia and 760 mm Hg - ( o F, o K ) -423, 20.4
Latent Heat of Evaporation at boiling point ( Btu/lb, J/kg ) 192, 447000
Freezing or Melting Point  at 1 atm ( o F, oC ) -434.6, -259.1
Latent Heat of Fusion ( Btu/lb, J/kg ) 25.0, 58000
Critical Temperature ( o F, oC ) -399.8, -240.0
Critical Pressure ( psia, MN/m2 ) 189, 1.30
Critical Volume ( ft3 /lb, m3 /kg ) 0.53, 0.033
Flammable yes
Heat of combustion ( Btu/ft3 , Btu/lb, kJ/kg ) 320, 62050, 144000

Follow the links below to get values for the listed properties of hydrogen at varying pressure and temperature :

See also more about atmospheric pressure , and STP - Standard Temperature and Pressure & NTP - Normal Temperature and Pressure ,
as well as Thermophysical properties of: Acetone , Acetylene , Air , Ammonia , Argon , Benzene , Butane , Carbon dioxide , Carbon monoxide , Ethane , Ethanol , Ethylene , Helium , Hydrogen sulfide , Methane , Methanol , Nitrogen , Oxygen , Pentane , Propane , Toluene , Water and Heavy water, D2O .

Hydrogen is a gas at standard conditions. However, at very low temperature and/or high pressures the gas becomes a liquid or a solid.

The hydrogen phase diagram shows the phase behavior with changes in temperature and pressure. The curve between the critical point and the triple point shows the hydrogen boiling point with changes in pressure. It also shows the saturation pressure with changes in temperature.


At the critical point there is no change of state when pressure is increased or if heat is added.

The triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.

Sponsored Links

Related Topics

Material Properties

Properties of gases, fluids and solids. Densities, specific heats, viscosities and more.

Related Documents

Acetone - Thermophysical Properties

Chemical, physical and thermal properties of acetone, also called 2-propanone, dimethyl ketone and pyroacetic acid. Phase diagram included.

Benzene - Thermophysical properties

Chemical, physical and thermal properties of benzene, also called benzol. Phase diagram included.

Combustion Heat

Heat of combustion (energy content) for som common substances - with examples how to calculate heat of combustion.

Critical Temperatures and Pressures for some Common Substances

Critical temperatures and pressures for some common substances like air, alcohol, ether, oxygen and more.

Cryogenic Fluids and Liquefied Gas Properties

Cryogenic properties as density, boiling points and heat of evaporation for fluids like hydrogen, methane, oxygen, nitrogen, fluorine and helium.

Ethane - Thermophysical Properties

Chemical, Physical and Thermal Properties of Ethane - C2H6.

Ethylene - Thermophysical Properties

Chemical, physical and thermal properties of ethylene, also called ethene, acetene and olefiant gas. Phase diagram included.

Fuel Gases - Heating Values

Combustion heat values for gases like acetylene, blast furnace gas, ethane, biogas and more - Gross and Net values.

Fuels and Chemicals - Autoignition Temperatures

Autoignition points for fuels and chemicals like butane, coke, hydrogen, petroleum and more.

Gases - Densities

Densities and molecular weights of common gases like acetylene, air, methane, nitrogen, oxygen and others.

Gases - Dynamic Viscosities

Absolute (dynamic) viscosities of some common gases.

Gases - Explosion and Flammability Concentration Limits

Flame and explosion limits for gases like propane, methane, butane, acetylene and more.

Gases - Ratios of Specific Heat

Ratios of specific heat for gases with constant pressure and volume processes.

Gases - Specific Gravities

Specific gravities of air, ammonia, butadiene, carbon dioxide, carbon monoxide and some other common gases.

Gases - Speed of Sound

Speed of sound in some gases at zero degrees Celsius and atmospheric pressure.

Helium - Thermophysical Properties

Chemical, Physical and Thermal Properties of Helium - He.

Hydrogen - Density and Specific Weight vs. Temperature and Pressure

Online calculator, figures and tables showing density and specific weight of hydrogen, H2, at temperatures ranging from -260 to 325 °C (-435 to 620 °F) at atmospheric and higher pressure - Imperial and SI Units.

Hydrogen - Specific Heat

Specific heat of Hydrogen Gas - H2 - at temperatures ranging 175 - 6000 K.

Hydrogen - Thermal Conductivity vs. Temperature and Pressure

Online calculator, figures and table showing thermal conductivity of hydrogen, H2, at varying temperature and pressure - Imperial and SI Units.

Molecular Weight of Substances

Definition and molecular weight (molar mass) of some common substances.

Pentane - Thermophysical Properties

Chemical, physical and thermal properties of pentane, also called n-pentane. Phase diagram included.

Solubility of Gases in Water vs. Temperature

Solubility of Ammonia, Argon, Carbon Dioxide, Carbon Monoxide, Chlorine, Ethane, Ethylene, Helium, Hydrogen, Hydrogen Sulfide, Methane, Nitrogen, Oxygen and Sulfur Dioxide in water.

Sponsored Links

Search Engineering ToolBox

  • the most efficient way to navigate the Engineering ToolBox!

SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Privacy

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.

AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.