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Specialty Chemistry Forums => Other Sciences Question Forum => Topic started by: bg105ee056 on December 07, 2006, 07:28:24 AM

Title: about hydrogen gas
Post by: bg105ee056 on December 07, 2006, 07:28:24 AM

how much hydrogen gas (volume) would be required to lift a mass of 1 K.g. Like in the case of an hydrogen balloon.

Title: Re: about hydrogen gas
Post by: Borek on December 07, 2006, 09:10:27 AM

Please learn how to properly use chemicalforums.

http://www.chemicalforums.com/index.php?topic=11796

http://www.chemicalforums.com/index.php?topic=11795

Title: Re: about hydrogen gas
Post by: billnotgatez on December 08, 2006, 08:00:55 AM

http://www.chemicalforums.com/index.php?topic=11795.0

Title: Re: about hydrogen gas
Post by: Donaldson Tan on December 08, 2006, 02:09:53 PM

The Ideal Gas Equation will give you a good estimate of the volume.

Title: Re: about hydrogen gas
Post by: kommyching on July 01, 2008, 10:10:09 AM

As the molar mass of hydrogen gas is 2 grams/mole.
1000 kg of hydrogen gas contains 500 moles of hydrogen molecule.
Under room condition(25 Degree Celsius and 1 atmospheric pressure), 1 mole of gas molecule occupy 24.0 cubic decimeter.
Therefore 500 moles= 500*24 cubic decimeter=1200 cubic decimeter.

Title: Re: about hydrogen gas
Post by: Borek on July 01, 2008, 01:38:18 PM

Quote from: kommyching on July 01, 2008, 10:10:09 AM

As the molar mass of hydrogen gas is 2 grams/mole.
1000 kg of hydrogen gas contains 500 moles of hydrogen molecule.

No. What is difference between g and kg?

Not that it is in any way related to the original question.

Title: Re: about hydrogen gas
Post by: Mitch on July 07, 2008, 02:52:55 AM

Umm... I actually wouldn't know how to approach this one, any suggestions? And if anyone says look at #1 in my sig....

Title: Re: about hydrogen gas
Post by: sjb on July 07, 2008, 03:35:12 AM

Quote from: Mitch on July 07, 2008, 02:52:55 AM

Umm... I actually wouldn't know how to approach this one, any suggestions? And if anyone says look at #1 in my sig....

Something along the lines of http://www.chem.hawaii.edu/uham/lift.html ? perhaps - but the figures seem a little low (not enough lift)

S

Title: Re: about hydrogen gas
Post by: Borek on July 07, 2008, 05:25:55 AM

Lift is the difference between mass of the liquid (gas) displaced and mass of the object (or buoyancy minus mass of the object itself). So, volume V of hydrogen displaces V air and lift is V(d_air-d_hydrogen). Density of air at STP is around 1.29 g/L, density of hydrogen at STP - around 0.089 g/L. That gives lift of 1.2 g/L, you need 1kg, so 830 L will do. That's neglecting mass of the baloon.

Densities can be easily calculated from pV=nRT and n=mass/molar mass, or even simpler from d = molar mass/22.4.