Sublimiation

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Justin_Ching_3I
Posts: 7
Joined: Wed Sep 21, 2016 2:55 pm

Sublimiation

Postby Justin_Ching_3I » Wed Jan 11, 2017 10:04 pm

I read in the course reader that sublimation is solid changing into vapor. Is vapor changing solid sublimation as well? If not, what is it called?

Manvita_Mareboina_3K
Posts: 12
Joined: Sat Jul 09, 2016 3:00 am

Re: Sublimiation

Postby Manvita_Mareboina_3K » Wed Jan 11, 2017 10:07 pm

If a vapor changes into a solid, this is known as deposition which is the opposite of sublimation.

NinaSheridan
Posts: 30
Joined: Wed Sep 21, 2016 2:58 pm

Re: Sublimiation

Postby NinaSheridan » Thu Jan 12, 2017 12:29 am

I looked this up too and also found that in the case of liquids going to solids (the opposite of fusion) it's technically called solidification or crystallization if that ever comes up anywhere :)

Jeffreyho97
Posts: 10
Joined: Fri Jul 15, 2016 3:00 am

Re: Sublimiation

Postby Jeffreyho97 » Thu Jan 12, 2017 3:46 pm

I may be wrong, but when I asked my TA this question, she said that in this course, the reverse of such phase change as sublimation would still be called the same. The difference is that the Delta H has a reversed sign: + to - .

Chris_Rudewicz_3H
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Joined: Fri Jul 22, 2016 3:00 am
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Re: Sublimiation

Postby Chris_Rudewicz_3H » Thu Jan 12, 2017 3:56 pm

No, that would be like saying when water turns into ice it's called melting. I believe it is called deposition.

Aashi_Patel_3B
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Joined: Wed Sep 21, 2016 2:57 pm

Re: Sublimiation

Postby Aashi_Patel_3B » Fri Jan 13, 2017 10:03 am

Adding onto the topic of sublimation, when we calculate the phase change reaction of sublimation, do we only calculate vapor and solid changes? Or do we follow the line of phase change, including the liquid part?

I remember the TA saying we always have to calculate ALL steps in between (that we cant skip phase changes), was hoping for clarification.

-Aashi

Chiao-Wei Cheng 3e
Posts: 16
Joined: Wed Sep 21, 2016 2:55 pm

Re: Sublimiation

Postby Chiao-Wei Cheng 3e » Fri Jan 13, 2017 4:48 pm

I could be incorrect, but I remember that we have to calculate all of the phase changes for sublimation.
(link: http://chem.libretexts.org/Core/Physica ... ublimation)

The heat of sublimation can be calculated by H(gas)-H(solid) or by adding the heat of fusion and heat of vaporization together.


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