phase change

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Sophia Dinh 1D
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

phase change

Postby Sophia Dinh 1D » Fri Mar 13, 2020 2:30 am

how can you tell if there has been a phase change?

Parker Smith
Posts: 102
Joined: Thu Jul 25, 2019 12:15 am

Re: phase change

Postby Parker Smith » Fri Mar 13, 2020 8:22 am

Usually the problem will tell you when a phase change occurs, or if on a phase diagram the temperature remains constant but enthalpy increases, the energy in crease was used for the phase change of the compound.

Sanjana Borle 2K
Posts: 111
Joined: Fri Aug 09, 2019 12:15 am

Re: phase change

Postby Sanjana Borle 2K » Fri Mar 13, 2020 8:39 am

Like the diagram in class, you can tell that there is a phase change when the heat or enthalpy is increasing, but the temperature is not increasing, or delta T is zero.

KBELTRAMI_1E
Posts: 108
Joined: Sat Jul 20, 2019 12:17 am

Re: phase change

Postby KBELTRAMI_1E » Fri Mar 13, 2020 10:02 am

Sanjana Borle 2K wrote:Like the diagram in class, you can tell that there is a phase change when the heat or enthalpy is increasing, but the temperature is not increasing, or delta T is zero.


Can the enthalpy increase AND the temperature remains the same while there still not being a phase change? Like I'm imagining the enthalpy of water at a positive value but without becoming a gas? Is that possible?

Ivan Tadeja 1G
Posts: 81
Joined: Fri Sep 28, 2018 12:28 am

Re: phase change

Postby Ivan Tadeja 1G » Sat Mar 14, 2020 12:22 pm

KBELTRAMI_1E wrote:
Sanjana Borle 2K wrote:Like the diagram in class, you can tell that there is a phase change when the heat or enthalpy is increasing, but the temperature is not increasing, or delta T is zero.


Can the enthalpy increase AND the temperature remains the same while there still not being a phase change? Like I'm imagining the enthalpy of water at a positive value but without becoming a gas? Is that possible?


I was wondering the same thing. Would any change in either of these, no matter to what degree, result in a phase change? Or is there an explicit threshold for each phase with regards to the reaction?

Julia Holsinger_1A
Posts: 50
Joined: Tue Feb 26, 2019 12:16 am

Re: phase change

Postby Julia Holsinger_1A » Sun Mar 15, 2020 6:29 am

Ivan Tadeja 1G wrote:
KBELTRAMI_1E wrote:
Sanjana Borle 2K wrote:Like the diagram in class, you can tell that there is a phase change when the heat or enthalpy is increasing, but the temperature is not increasing, or delta T is zero.


Can the enthalpy increase AND the temperature remains the same while there still not being a phase change? Like I'm imagining the enthalpy of water at a positive value but without becoming a gas? Is that possible?


I was wondering the same thing. Would any change in either of these, no matter to what degree, result in a phase change? Or is there an explicit threshold for each phase with regards to the reaction?

I believe because enthalpy is a state function there are explicit thresholds for each phase which is why, when plotted, it is a step diagram. That is how I understood it, there could be a different explanation

Ivan Tadeja 1G
Posts: 81
Joined: Fri Sep 28, 2018 12:28 am

Re: phase change

Postby Ivan Tadeja 1G » Sun Mar 15, 2020 7:48 am

Julia Holsinger_1A wrote:
Ivan Tadeja 1G wrote:
KBELTRAMI_1E wrote:
Can the enthalpy increase AND the temperature remains the same while there still not being a phase change? Like I'm imagining the enthalpy of water at a positive value but without becoming a gas? Is that possible?


I was wondering the same thing. Would any change in either of these, no matter to what degree, result in a phase change? Or is there an explicit threshold for each phase with regards to the reaction?

I believe because enthalpy is a state function there are explicit thresholds for each phase which is why, when plotted, it is a step diagram. That is how I understood it, there could be a different explanation


That is how I initially believed it to be. Are all diagrams for phase changes step diagrams?


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