What if H2O became just H and O?

[threaded]

The hydrogen would just float up to the top wouldn't it?

Correct.

The Hindenburg disaster is a case in point. As soon as a gas cell ruptured the hydrogen would have shot up in the air so fast that only a small amount of it actually burnt. All the flames were from the fabric.

[VectraMan]

What if H2O became just H and O?

What happens to the 2?

[Grinder]

I can see its a difficult calculation and probably not worth people's time.

I like the idea (for the movie) that the atmosphere would be denser and you could kind of swim about in the air.

What happens to the 2?

What do you want to happen? <shrug>

[TimberWolf]

I can see its a difficult calculation and probably not worth people's time.

I like the idea (for the movie) that the atmosphere would be denser and you could kind of swim about in the air.


What do you want to happen? <shrug>

The old atmosphere would be a trace gas, so not worth considering.

[Grinder]

The old atmosphere would be a trace gas, so not worth considering.

Something that currently envelopes the whole earth to a height that probably exceeds the depth of the deepest part of the ocean - I guess its due to difference in the densities....

[TimberWolf]

Something that currently envelopes the whole earth to a height that probably exceeds the depth of the deepest part of the ocean - I guess its due to difference in the densities....

The air presses down on us with a force of one atmosphere (about 10 tonnes per square metre). That's the extra pressure at a depth of only 10m underwater. The worlds oceans (1.4*10^21 Kg) would cover the Earth to a depth of about 3 km, and at 3 km down the pressure would be about 300 times atmospheric pressure. So the atmosphere contains much less mass than the oceans and yes air is much less dense than water and gets less dense with height (about 1/1000 the density of water at the surface).

[Turion]

Water is 700 times denser than air so the massive quantities in the oceans will 'drown' the existing atmosphere. Pressure would greatly increase, and so the height of the atmosphere would increase. One effect would be that satellites would become caught up in the atmospheric drag and come down like shooting stars. Thousands of sats and space debris would be raining down on the earth like fireballs of death.....

Sounds like it could be a great Hollywood blockbuster

[Grinder]

We have the answer.

[Mich the Tester]

I posed this question to Any Questions Answered when they first started offering the service. The answer was rubbish (basically "it wouldn't happen") and I got my £1 back.

So my learned colleagues here is my pseudo-science question for you.

If all the water in the world somehow* got converted to Hydrogen and Oxygen, what would be the resultant proportion of gases in our atmosphere and would it be breathable?

* I'm thinking of some non-existing catalytic process, perhaps caused by research into alternative fuels. I know it wouldn't actually happen.

Please note I am writing a movie script based around this scenario, so please no one can use if for that.

There would have to be a strict no-smoking policy.

[KentPhilip]

Water is 700 times denser than air so the massive quantities in the oceans will 'drown' the existing atmosphere. Pressure would greatly increase, and so the height of the atmosphere would increase. One effect would be that satellites would become caught up in the atmospheric drag and come down like shooting stars. Thousands of sats and space debris would be raining down on the earth like fireballs of death.....

Sounds like it could be a great Hollywood blockbuster

Yeah and some of the atmosphere would extend up as far as the moon, and the extra drag on its orbit would cause it to come crashing down to earth and we'd all die.