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Visible Gas? Answered

I wan't to fill a chamber with hydrogen, have a chamber of the same size linked with it, with a heavy visible gas in it, then as I pump out the hydrogen the heavy gas displaces it and I can see when I need to stop pumping and refill with hydrogen.  What gas can I use,  I know just about any visible gas will work because hydrogen is the lightest, but it would be nice if it was heavier than average air so I could allow air to flow into my heavy gas chamber to displace it.  Or can I just die the air with some kind of smoke from my smoke machine.
Yes hydrogen is extremely explosive, so this would be on a very, very small scale with hopefully 0 oxygen.



Best Answer 7 years ago

Visible gases tend to be toxic (chlorine, bromine), and the hydrogen would mix with them anyway.

The easiest and safest fluid to use would be water.

Place the water tank above the hydrogen tank, and simple gravity will let it flow into the hydrogen chamber. It would have the added advantage of pressuring the hydrogen slightly, so it flows out at a useful rate.

Thanks, I figured I would be stuck with water. Do you know if an air compressor in an hydrogen environment would be dangerous. It would only be hydrogen, but I want to make sure that if I had a small amount of oxygen enter I wouldn't be dealing with a ruined compressor (like a small one for footballs and basketballs.) I am doing this because I can't find any compressors that actually have an inlet. And I couldn't produce enough hydrogen to keep up.

You could try smoke or an oil dispersion "fog", but gasses are not immiscible and you aren't going to get a clean line. Liquid is better, and is in fact is the classic solution. Or you could try an inflatable nonpermiable container such as a mylar balloon.

H2 by itself is highly _flammable_ and burns very hot, but is not explosive unless thoroughly mixed with oxygen. Many things can be explosive when sufficiently mixed with oxygen; that's why grist mills had to be so careful about using non-sparking implements.

Ok, I just wanted to make it clear that this would be safe, thanks.

As far as the compressor goes: I think the biggest hazard would be sparks from the motor which drives the compressor.

Bear in mind that the lower explosive limit for hydrogen in air is ~4.5%.
Handling H2 is a risky business.


"hopefully" doesn't hack it with H2.


Watch the mythbusters episode, its kinda cool that the hydrogen wasn't the only fault.

But, it won't be explosive with the amount my "hopefully" delivers