chemistry/physics question

[cellar701]

Yes. That is kind of the way Goretex works.

 

[wwb]

In order for a substance to pass through any membrane, the pores must be large enough to accomodate the individual molecules. "Water vapor" (water in the gaseaous state) is rather tough to deal with, as the molecule size is not well defined at lower temperatures (any temp where the vapor pressure is lower than the ambient atmospheric pressure) since it may have groups of more than one molecule clumped together. Add to that the fact that some membranes will repel water (primarily those composed of or treated with non-polar materials) while some will attract and pass water quite easily.

 

[Selena]

Schrödinger would tell you yes and no at the same time.

 

[gramps]

No such thing as being water tight, but not airtight in an container. IMO. If air can escape then it can suck in water!
gramps

 

[slayer61]

Schrödinger would tell you yes and no at the same time.

Schrodinger was a weird cat!

 

[Busterswoodshop]

It is basically like a liberals brain. Crap can get in but it can never get out.

 

[Selena]

Schrödinger would tell you yes and no at the same time.

Schrodinger was a weird cat!

OK, I should be serious, RKDS, try looking up semi-permeable membranes. That maybe the scenario you are looking for... Then again...

Dirac spoke of energy levels,
Both minus and plus. Oh, how droll!
And now, just because of his teaching,
We don’t know our mass from a hole.

 

[coach]

I would say since water vapor is part of the makeup of air, anytime air can get somewhere so will water vapor.

 

[Phoenix too]

And to add to all that, a water molecule is a bi-polar molecule (It actually looks like a Mickey Mouse head.) As a constituent of air, it will be on the walls of the container in a quantity affected by humidity and by the temperature of the wall as has been pointed out.

Another issue to consider is Dalton's Laws of partial pressure, which state that gases, left to their own devices, will try to mix equally. If the inside of the container is very dry, and the humidity of the surrounding air is high, those water molecules will be trying very, very hard to get in.

But, I do love the cat. Very clever.

 

[Rick Courtright]

Hi,

Kinda funny that, after an absence of several years, Schrödinger has popped up a second time today in totally unrelated conversations. Earlier in the afternoon before checking this thread, my sister in law had commented Schrödinger is why cats always try to get in boxes. Makes as much sense as anything cats, or physicists, concentrate on!

Rick C

 

[6GUNSONLY]

Hmm. Learned something new today.. I think...?

 

[KWYJIBO]

Schrödinger would tell you yes and no at the same time.

Actually, he'd say that it is neither dry nor wet before we open it to have a look; its state is undetermined. As soon as we check, it assumes either a dry or wet state, and our act of observation is what causes this.

Sorry to hijack the thread. I'm with Gramps--you can't have something that is watertight but not airtight.

 

[Number9]

Everything known tries to seek a balance...

which brings up the question...

why would RKDS ask this question? :mrgreen:

 

[Number9]

For a period of "time"..

Will water _vapor_ get into a container that is watertight but not airtight?

.. the answer could be "No".

If you had a bottle of say, dry nitrogen.. and opened the valve slightly so the gas could leak out slowly.. and sink it in water..it wouldn't be "airtight", but it would be "watertight".
Until the pressure equalized.. then it wouldn't be watertight.

 

[Phoenix too]

To continue: http://www.youtube.com/watch?v=YhMiuzyU1ag&feature=player_embedded