[Question] Steam coming from my mouth when air is compressed?

[quan chi2]

Hey, I'm new here and I didn't really know where to ask this question. I figured that since we breathe out CO2, then this might be a question for the chemistry catagory.

 

So anyway, I'm wondering why steam comes out of my mouth when I sqeeze the gas inside of my mouth. It could be oxygen that I'm sqeezing, but it could also be the CO2 that I'm squeezing too.

 

For all of you who are wondering, to make the steam come out of your mouth, fill your mouth with some type of air, then puff your cheeks out as if you are playing the trumpit. Then softly and slowly open your lips. Some type of steam-looking gas will come out.

 

Why is that?

 

Thanks in advanced, guys.

[psynapse]

In cold weather perhaps?

This is simply the water vapor condensing, because the air that leaves your mouth is warm and when it comes into contact with cold air the water vapor will condense.

[Phi for All]

You smoke cigarettes, don't you? It could be residual smoke from your lungs. When you fill your mouth with air you're using your lungs to compress the air in your mouth.

[blike]

In cold weather perhaps?

This is simply the water vapor condensing' date=' because the air that leaves your mouth is warm and when it comes into contact with cold air the water vapor will condense.[/quote']It actually works in any weather, even a hot steamy florida day. I usually have to build up more pressure than the "trumpet" method the OP mentioned. I hold my mouth shut and try and force air out as hard as I can. Then you gently open your lips and puff out.

 

Good question OP, I'll see if I can dig up something in a little bit.

 

You smoke cigarettes, don't you? It could be residual smoke from your lungs. When you fill your mouth with air you're using your lungs to compress the air in your mouth.

I don't smoke and occasionally I can get a little to come out. But right now it's not working

[Phi for All]

I don't smoke and occasionally I can get a little to come out. But right now it's not working

You LIE!!! I saw that photo of you and Fidel with those monster stogies!

[insane_alien]

this is a pretty simple phenomenon. the air in your lungs is saturated with water vapour. when you force air into your mouth and it gets compressed, it can hold slightly more water vapour. so some of the spit in your mouth evapourates(a really tiny amount). when you release the air, the pressure drops and the air can no longer hold all the water vapour so it condenses out.

 

this isn't steam, as steam is perfectly transparent but little tiny dropplets of water. a similar effect is seen when planes depressurize suddenly at altitude. the cabin will become foggy as excess water vapour condenses out from the sudden pressure change.

[quan chi2]

In cold weather perhaps?

This is simply the water vapor condensing, because the air that leaves your mouth is warm and when it comes into contact with cold air the water vapor will condense.

 

Not cold weather. I can do it in warm weather too.

 

You smoke cigarettes, don't you? It could be residual smoke from your lungs. When you fill your mouth with air you're using your lungs to compress the air in your mouth.

 

No, I do not smoke, nor have I ever tried a cigarette in my life.

 

It actually works in any weather' date=' even a hot steamy florida day. I usually have to build up more pressure than the "trumpet" method the OP mentioned. I hold my mouth shut and try and force air out as hard as I can. Then you gently open your lips and puff out.

 

Good question OP, I'll see if I can dig up something in a little bit.[/quote']

 

Yeah, exactly. I had trouble explaining the method. Anyway, thanks.

[Phi for All]

No, I do not smoke, nor have I ever tried a cigarette in my life.

Good for you! I'm more than happy to be wrong in this case.

[John Cuthber]

"when you force air into your mouth and it gets compressed, it can hold slightly more water vapour."

Why?, the vapour pressure of water is not dependent on the external pressure (at least, not at the temperatures and pressures we are talking about here).

 

On the other hand, when the pressure is dropped again the air cools, it can hold slightly less water vapour.