What is vapor-gas?

James McGinn

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Jan 17, 2017, 11:09:49 AM1/17/17

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On Monday, January 16, 2017 at 10:38:57 AM UTC-8, edpr...@gmail.com wrote:

> > Someone's boiling a kettle of water where the kitchen temperature is
> > 20⁰ C, atmospheric pressure 1 atm. The water boils and bubbles and
> > the water temperature stays at 100⁰ C. When the bubble floats to the
> > top, it burst and become steam vapor(NOT GAS) - you're right.
>
> OH, so close. the bubble is gaseous water. true once out of the kettle
> and mixing with air, two things happen to the water vapor (gas):

What is a water vapor (gas)?

> 1. temperature drops due to mixing with cooler air
> 2. the air water mixture now has relative humidity above the dew point
> As a consequence, SOME of the water condenses to droplets.

SOME? How many? What percentage? And how did you detect the part that you
claim to, seripticiously, still be gas? Where is the data and the
reproducible, experimental procedures? Bring if forth or, if you prefer,
make a retraction. Fair enough?

> Note these
> droplets are clearly visible. But notice a strange thing that JM's theory
> cannot explain. About a a foot (30cm) away, the droplets disappear.

LOL. Feel free to make a detailed argument to that effect.

> This is due to the air water mixture continuing to mix with the larger
> volume of air in the room. The relative humidity in the large volume is
> below the dew point and those droplets because of their high surface area
> per volume of each drop evaporate back to gaseous water as long as the
> partial pressure of the water in the air is below the value that you (Chan) found to be true as you mention here:

So, let me get this straight. Firstly, only some of the gaseous H2O stays
steam at temperatures below the boiling point of H2O. I think that absurd.
But that doesn't mean it is wrong. Where is the data and the reproducible,
experimental procedures? Bring if forth or, if you prefer, make a
retraction. Fair enough?

Actually, none of it stays gaseous. As soon as it hits the atmosphere and
begins to cool below the boiling point it becomes liquid and--
instantaneously--the huge heat capacity of liquid H2O appears on the scene
(as if out of nowhere) and begins capturing energy. (Note: this is a
consequence of the huge heat capacity of *LIQUID* H2O--something that does
not exist in the gaseous phase). Consequently, With the only exception being
extremely voluminous and high speed streams of gaseous H2O (of volcanic or
extraterrestrial origin) all gaseous H2O turns to liquid H2O almost
instantly when it hits the atmosphere.

(BTW, H2O's high heat capacity is the same reason gaseous H2O must be
pressurized in order to capture and maintain it, as in a steam engine. It's
high heat capacity keeps soaking up energy as it approaches boiling. And
then if you do contain it the boiling point of H2O increases rapidly with
the, inevitable, increases in pressure associated with containment. So, an
incredible amount of heat has to be put into H2O to get it to flash into
steam and maintain it as such.)

> > There is usually water vapor gas in the atmosphere at 20⁰ C
> > 1 atm pressure. The gaseous water contributes just a tiny pressure
> > (partial pressure) of 0.023 atm to the total 1.0 atm.
>
> Note the 0.023 is at 100% relative humidity.

Meaningless. (It's the pressure the gaseous H2O produces when it *BOILS* in
a vacuum at 20 degrees Celsius.)

> So as long as the air
> in the room has relative humidity less than 100%, the water that did
> condense at the opening of the kettle will evaporate back to gaseous
> form, and back to being invisible.

Impossible. If it becomes invisible that is because the microdroplets are
smaller than a photon. It does not become steam, and since evaporation
produces evaporate (not gaseous H2O) it certainly does not, "evaporate" into
gaseous H2O.

> > JM: "There is nothing wrong with the laws. Gas laws are applicable
> > to gases, not vapor.
> > It's that simple. Vapor pressure and partial pressure of multiple
> > gases are two different subjects."
>
> Sorry JM you are off the track. You can try but it is exactly the
> correct and same subject.

So you're saying we should take your word on that? Sorry, nothing personal,
I don't take anybodies word on anythings. Feel free to submit any data that
supports this assertion.

> > ***They are the same! Vapor pressure contributes to total
> > pressure as (partial) pressure.***
> > A vacuum of volume V filled with enough water at 20⁰ C will
> > finally have gaseous water vapor in the container - exactly 0.023 atm.
>
> at saturation (100% humidity).

True, but . . . relevance?

> > This gas vapor CAN mix with V volume of dry oxygen gas at 1 atm
> > to give a:
> > *** mixture of gases oxygen + water vapor gas, same volume V,
> > total pressure 1.023 atm ***
>
> in a closed container. in the open kitchen or lab, the air will expand
> so the total pressure is back to 1.0 atm, with a portion of that due to
> water vapor.

True but, . . what does that explain?

> you seem to be learning Chan. Good for you.

I finally found something I agree with you on, Edster!
- show quoted text -

James McGinn

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Jan 18, 2017, 1:55:21 AM1/18/17

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