Why is hydrogen gas lighter than air?

Answer 1

[answerer one]

the word hydro =water and if water evaporates it transforms into a content of air and hydrogen is a gas which is made up of evaporated liquid this is why hydrogen gas is lighter air

[answerer two]

Let me take this from a purely chemical point of view. One mole of oxygen gas weighs 32 grams, one mole of nitrogen gas weighs 14.01 grams. At standard temperature and pressure, one mole of gas takes up 22.4 liters of space. Earth's atmosphere is (approximately) 78% Nitrogen, and 22% oxygen, knowing that, one can figure that 22.4 liters of air contains .78 moles of nitrogen, and .22 moles of oxygen, which translates into 7.0 grams of oxygen and 11 grams of nitrogen (approximately). So, the density is 18/22.4 grams per liter.

Lets compare that to the density of 22.4 liters of hydrogen. 1 mole of hydrogen weighs 1.01 grams, so the density is 1.01/22.4 grams per liter.

So, the density of air is 17.821 times more than the density of helium.

Correct me if I'm wrong though, I'm still learning chem.

[edit] i was a bit off, but i don't know why. I'm assuming hydrogen to be H-1 isotope, but it could be H-2.

Because the atomic weight of hydrogen is lower than the atomic weights of the atomss that typically form "air", namely nitrogen, oxygen, carbon dioxide, and a bunch of other gasses in extremely small concentrations. With lower density, the atoms of hydrogen tend to want to "float" just like liquids behave when different densities are mixed. Hydrogen is #1 on the Periodic Table of the elements because it has the lowest atomic weight

Hello im another person

Air weighs 34 tins of baked beans- with nothing inside , this is because of gravity, but if you would weigh it without gravity it would be 17 tins without anything inside

so even with gravity hydrogen will be lighter

because if hydrogen was 6g- causing gravity, then it would be 3g without gravity

dont forget hydrogen is flammable, so it is lighter, but air isnt flammable, so it must be heavier.

think of a paper, weigh it about 3g, so burn it about 1g since it all goes together like a family and turns black.

By Susana25

also by another person

the first bit

until hello im another

person!

Thank you for reading.

Answer 2

Hydrogen's Atomic Mass is much smaller than all of the other gases in air. The smaller the mass of a substance the lighter it is. The greater the mass, the heavier the substance becomes.

Added:Molar masses of H2 and air (80% N2 and 20% O2) are repectively: 2 g/mole H2

and (0.80*28 g/mole N2 + 0.2*32 g/mole O2)= 28.8 g/mole 'air'

That is also the ratio of their (gas) densities. I.e. 1 : 14.4

so hydrogen is 14.4 times lighter than air

Answer 3

Air is composed of about 23% Oxygen, 70+% Nitrogen, and the rest is other gases. Of all the elements Hydrogen has the lowest mass. All the other gasses in air have much higher mass and are consequently, more dense.

Answer 4

Hydrogen is a specific element. "Air" is a mixture of Oxygen, Nitrogen, Carbon Dioxide and various other elements and compounds. In its elemental gaseous form. Pure (H) or hydrogen is lighter in molecular weight than all the major components of "Air" thus Hydrogen is lighter than "Air". According to the periodic table, Pure elemental hydrogen is also lighter than pure elemental oxygen.

Answer 5

yes. that's what they suspect was in the Hindenburg

Answer 6

It is lighter than air.