Anonymous asked in Science & MathematicsChemistry · 1 decade ago

C1. Properties of hydrogen?

Q1. Describe the physical properties of hydrogen.

2 Answers

  • 1 decade ago
    Favorite Answer

    Hydrogen is the lightest element with an atomic mass weight of about 1.007 amu. In it's stable state it has 1 proton, 1 neutron, and 1 electron, although it's isotopes vary...It's phase at room temperature is gas, and it is colorless and odorless.

    When put together with oxygen it makes water (duh =]) with a 2:1 ration.

    Yep, those are the more basic properties of hydrogen.

  • 1 decade ago

    * Atomic Mass Average: 1.00794

    * Boiling Point: 20.418K -252.732°C -422.918°F

    * Coefficient of lineal thermal expansion/K-1: N/A

    * Conductivity


    Thermal: 0.001815 W/cmK

    * Density: 0.0899g/L @ 273K & 1atm

    * Description:

    Tasteless, colorless, odorless and extremely flammable gas.

    * Enthalpy of Atomization: 217.6 kJ/mole @ 25°C

    * Enthalpy of Fusion: 0.059 kJ/mole

    * Enthalpy of Vaporization: 0.449 kJ/mole

    * Flammablity Class: Highly flammable gas

    o Auto Ignition Temp: 773K 500°C 932°F

    o Explosive Limits

    Lower (LEL): 17%

    Upper (UEL): 56%

    o Flammable Limits

    Lower (LFL): 4%

    Upper (UFL): 75%

    o Flash Point: 20K -253°C -423°F

    Theoretical (there are no oxidizing materials i.e. oxygen in the gas state at this temperature, which is necessary to support combustion.)

    * Freezing Point: see melting point

    * Heat of Vaporization: 0.44936kJ/mol

    * Melting Point: 14.175K -258.975°C -434°F

    * Molar Volume: 14.1 cm3/mole

    * Optical Refractive Index: 1.000132 (gas) 1.12 (liquid)

    * Physical State (at 20°C & 1atm): Gas

    * Realitive Gas Density (Air=1) = 0.0694

    * Specific Heat: 14.304J/gK

    * Vapor Pressure = 1570mmHg@-250°C

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