Water bath and water vapor + air mixture in a closed system

[MacIntoShiba]

Hello,

At my work I came up with the following question:

Say we have a vacuum chamber. Inside the vacuum chamber we have at the bottom a water bath. The rest of the chamber is filled with a air and water vapor mixture. The whole system is placed in a room, is at room temperature and is in equilibrium.

Since the system is in equilibrium the relative humidity should be 100% (is this correct?). Therefore the partial water vapor pressure should be the same as the water vapor pressure at room temperature (for example given by the Buck equation). This water vapor pressure is only a function of the temperature.

Does this mean that the amount of air (raising the pressure in the vacuum chamber) has no effect on the amount of water vapor inside the vacuum chamber?

Does this mean that if at the start the air has 0% relative humidity (the whole system is still at room temperature) in which case the air pressure is p_air will increase to p_air + p_vapor when the system in back in equilibrium?

I feel like I am missing something.

 

[Chestermiller]

Yes to all your questions.

 

[MacIntoShiba]

Its a bit counter intuitive, I would expect the air pressure to play a role here. Thank you for your reply.