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Evaporation in a Closed Object

02/01/2011 10:21 PM

can evaporation occure in a closed object?

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#1

Re: evaporation

02/01/2011 10:25 PM

no

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#2

Re: evaporation

02/01/2011 10:41 PM

If there is "air space" in the closed object, yes. But, only to a point.

We aren't doing you homework, are we?

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#3
In reply to #2

Re: evaporation

02/01/2011 10:46 PM

yes doing homework.have to ask an expert a few questions for project,are you an expert?

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#4
In reply to #3

Re: evaporation

02/01/2011 10:57 PM

Probably not as far as your teacher is concerned. I'm just an anonymous CR4 junkie. "Experts" are usually knowledgeable in a specific subject. Are you studying evaporation?

We don't mind helping, if we know it's homework and you don't just want us to do all the work for you.

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#5

Re: evaporation

02/02/2011 12:38 AM

The idea of question is to make you apply your acquired knowledge to figure it out.

Write down what you know about the subject and try to convince yourselves either way.

Imagen a centrifugal pump as a closed system. the water in the eye will "boil"/evaporate because of low pressure. why?

If you suck the air out of a half full bottle will water evaporate?

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#6
In reply to #5

Re: evaporation

02/02/2011 1:02 AM

hey are you a expeert ?

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#7
In reply to #6

Re: evaporation

02/02/2011 5:02 AM

What is an "expeert"?

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#15
In reply to #6

Re: evaporation

02/03/2011 12:19 AM

Not an expert but I depend on the evaporation of water to exist.

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#8
In reply to #5

Re: evaporation

02/02/2011 7:50 AM

"Imagen a centrifugal pump" Really!

How can you expect a child to, "Imagen a centrifugal pump"??????????

You are asking them to imagine something they could not possibly comprehend! .

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#9

Re: Evaporation in a Closed Object

02/02/2011 7:57 AM

Can? It does. Example: closed butane storage cylinder.

Evaporation and condensation always proceed towards equilibrium conditions at whatever temperature and pressure the system is subjected to.

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#10

Re: Evaporation in a Closed Object

02/02/2011 11:02 AM

Certainly evaporation can happen in a closed space. So can condensation happen in a closed space. One can even have both happen in a closed space at the same time. One can even have a closed space that prevents evaporation.

You were given a very good analogy earlier on evaporation involving pop corn. The only drawback of this analogy is that one cannot un-pop pop corn. (Hmm, that gives me some ideas on the matter anti-matter paradox. But I digress.) So just imagine that you can un-pop pop corn and that it takes either a lot of pressure to un-pop the corn or for the popcorn to cool down enough. Now think about putting un-popped reversible popcorn on an open frying pan, an open pot, a closed pot with a few kernels and a closed pot almost full of kernels. Tell us what will happen when you heat each of these on a stove.

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#11
In reply to #10

Re: Evaporation in a Closed Object

02/02/2011 11:18 AM

Both happen in a closed space at the same time would give you a heat pipe. Photo below from Wikipedia:

Alaska pipeline support legs cooled by heat pipes to keep permafrost frozen

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#12
In reply to #10

Re: Evaporation in a Closed Object

02/02/2011 11:31 AM

hey redfred do you happen to be an expert?I need to ask a few questions to an expert

or if any experts i may ask

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#13
In reply to #12

Re: Evaporation in a Closed Object

02/02/2011 12:42 PM

My formal expertise is not evaporation and distillation. I am an Electrical Engineer. But part of my formal training does include the Chemistry and Physics that involves evaporation. I am particularly familiar with the difficulty that water poses to producing an ultra high vacuum (UHV). Without knowing what type of questions you might ask though I cannot guess if I should be considered an expert in evaporation or who you should ask. What do you want to know about evaporation?

A warning for you: I believe in what's known as the Socratic method of teaching. I teach by answering a question with a question, at least for the first question. If you do not answer my questions, I cannot help you.

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#14

Re: Evaporation in a Closed Object

02/02/2011 8:33 PM

Would you consider a pot of water (with a lid) on the stove a 'closed object'? Even with no heat applied, some evaporation will occur -- until an equilibrium is reached, when the rate of evaporation equals the rate of condensation. This equilibrium point depends on the temperature of the air.

If you turn on the burner, the water will evaporate at a faster rate; and as the air above the water gets hot it can hold more evaporated water. Eventually the water will boil and the pressure of the air will rise until the lid is forced up letting some steam escape.

You might also look up (google) the phrase 'pressure cooker'.

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Anonymous Poster (1); Glenn Summers (1); Hendrik (2); lyn (4); PWSlack (1); redfred (2); sciencekid? (3); Usbport (1)

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