Is methane gas lighter than oxygen?

and carbon dioxide too?

define "lighter"

Lighter as in if concealed in a box, which would float on top of the other. Maybe the term would be lowest density.

lol. lower density at a simple quess

Just curious, but what other kinds of "lighter" are there?

In terms of Avagadro's law, yes methane is lighter than O2 and CO2

at the same time, you have to consider the ideal gas law...

Just curious, but what other kinds of "lighter" are there?

lol

brighter, an igniter, less weighty

Generally speaking, gasses with a low molecular weight will be less dense than gasses with a higher molecular weight. That is why hydrogen gas is the least dense gas in existance, and why sulfur hexafluoride is basically the densest.

Wha? Sulfur hexafluoride? Never heard of it, sounds rather dense though.

Anyone else get the feeling that this has gone way off a very simple question?

It was obvious what he was trying to say.

Well, it wasn't too clear if he meant the O2 weight vs. CH4 weight or something else.

lol. if some one is asking if the gas is lighter than another gas then I dont think they would be thinking about the atomic weight.

"lol. if some one is asking if the gas is lighter than another gas then I dont think they would be thinking about the atomic weight."

 

Well... who knows.

Wha? Sulfur hexafluoride? Never heard of it, sounds rather dense though.

 

Sulfur Hexafluoride is a VERY inert and VERY dense gas. It's used in the electronics industry to provide an inert atmosphere that will be so much denser than the other gasses that it really doesn't allow any contamination. If you inhale a little bit of it, your voice will become VERY deep, and the only way to get it out of your lungs is to basically turn upside down and cough it out. It's pretty neat stuff.

Whoah, sounds rather interesting. But I don't think that I voluntarily want to breathe sulfur containing gases. Or is it so inert that it doesn't cause any problems like for example your lungs breaking into a bloody pulp?

it`s quite inert

 

and don`t worry about the Fluorine component either, Halokanes are used regularly as anaesthetics (inhaled) certain halogen compounds can be used a temp blood substitutes also (in combo with others).

 

they`re medical lifesavers really!

I want some, try and get a mix of helium and that stuff to sound normal, lol.

got any density figures for this sulphur hexaflouride

SF6 has a density of about 6.164 g/L, so that is INCREDIBLY dense for a gas. It is fully non-toxic, but it can still be lethal. Since it's so much denser than air, if you inhale too much it can quickly asphyxiate you. Plus, since it's so dense it's hard to expel from your lungs. (At about 500 degrees celcius, it will also decompose into fluorine gas and sulfur.)