Re: Terminology Confusion

[Robert A Cohen <bbq@ESU.EDU>]

On Wed, 14 Jul 1999, Gordon Smith wrote:

> If I have a closed container, with gas at some pressure and temperature,
> and a pool of water at the bottom, I eventually reach an equilibrium state
> wherein the vapor leaving the water is the same as the vapor entering the
> water.
>
> My confusion: Is the gas above the water saturated with water vapor?

I would also argue with this terminology.  It is the *space* that is
saturated with water vapor.  At a certain temperature, there is a specific
maximum amount (pressure) of water vapor that can exist.  This amount is
independent of how much other gas there is (assuming reasonable limits).
The space may have originally been a vacuum, in which case at equilibrium
the space only contains water vapor (at 0C, the pressure of the water
vapor at saturation would only be 0.006 atm).

----------------------------------------------------------
| Robert Cohen               Department of Physics       |
|                            East Stroudsburg University |
| bbq@esu.edu                East Stroudsburg, PA  18301 |
| http://www.esu.edu/~bbq/   (570) 422-3428              |
|                            **note new area code**      |
----------------------------------------------------------