Boiling point at room temperature

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Mitch Mologne 1A
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Joined: Fri Sep 29, 2017 7:04 am

Boiling point at room temperature

Postby Mitch Mologne 1A » Tue Feb 13, 2018 4:57 pm

When you are finding the boiling point of water at room temperature, why do you have to cool the water back down to room temperature?

Sean Monji 2B
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Joined: Fri Sep 29, 2017 7:06 am

Re: Boiling point at room temperature

Postby Sean Monji 2B » Tue Feb 13, 2018 10:09 pm

If you are talking about the case in which water will boil at lower temperatures due to extremely low pressures, it is more like you are trying to find the atmospheric pressure than the temperature.
Otherwise, it doesn't really make sense, since water of course won't usually boil at room temperature.

Abigail Urbina 1K
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Joined: Thu Jul 27, 2017 3:01 am

Re: Boiling point at room temperature

Postby Abigail Urbina 1K » Tue Feb 13, 2018 10:12 pm

I was wondering the same question. Saw this exact same concept applied to a question on the 2015 Winter Midterm

Sean Monji 2B
Posts: 66
Joined: Fri Sep 29, 2017 7:06 am

Re: Boiling point at room temperature

Postby Sean Monji 2B » Wed Feb 14, 2018 3:12 pm

If you are trying to find the boiling point of water at room temperature, the water must first be at room temperature. From there, you can calculate (I don't know how) the other various, non-standard conditions to allow this to be true, like a rapid change in pressure.

CalebBurns3L
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Joined: Fri Sep 29, 2017 7:07 am

Re: Boiling point at room temperature

Postby CalebBurns3L » Fri Feb 16, 2018 12:08 pm

I am also confused about this. The way that we're supposed solve the problem suggests that after boiling, the water cools back down to room temperature. Wouldn't the water just condense again?

Sirajbir Sodhi 2K
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Joined: Sat Jul 22, 2017 3:00 am

Re: Boiling point at room temperature

Postby Sirajbir Sodhi 2K » Fri Feb 16, 2018 4:18 pm

We know the vaporization of water is non-spontaneous at room temperature, so we must first heat it up to 100, boil it, and then cool it back down. A lot of the water would condense -- you are right -- but like much of what we do, this is a simplification that allows us to calculate the change in a state function (has to be a state function) that comes from boiling water at room temperature.


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