Air doesn't hold water - I need to prove it!

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I know that there is an "accepted" belief that "warm air holds more water than cold air", but this compromise in accuracy leads people to believe that evaporation is a quality held by the air rather than the energy held by the water molecules. Water is just a constituent of the blend of gasses that we call air - but it isn't "HELD" by air.

I teach people the science of drying out flooded houses. This belief that air holds water has produced many faulty drying strategies. I need to be able to demonstrate through a simple experiment that evaporation is a function of the water molecule - not a function of the air.

The only way I could think of doing this demonstration is to produce a very strong vacuum in a vacuum bell with a dish of water in the chamber. Given a strong enough vacuum, the water shall boil (I need to get the vacuum down to 2 or 3 torr in order to make the water boil). Not the easiest of tasks and requires some pretty specialized devices.

Can anyone out there assist me in a simpler experiment that can demonstrate this fact of physics?

Thanks everyone.

Ken Larsen

Moldenboy (talk)10:10, 10 April 2010